MODULATORS OF PrPC AND USES THEREOF

Abstract

The present invention relates to compounds capable of modulating the activity of the cellular prion protein (PrPC) and their use for the treatment of immune and neurodegenerative diseases.

Claims

1. Method of treating of a neurodegeneratie disease or an immune disease in a patient in need thereof with a compound of general Formula (I): ##STR00190## wherein A is a benzene ring or a five- or six heteroaromatic ring; B is a benzene ring of general structure: ##STR00191## or B is a five- or six membered heteroaromatic ring optionally substituted by one or more substituents each independently selected from hydrogen, halogen, nitro, cyano, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-4alkyl, hydroxy, SC.sub.1-4alkyl, OC.sub.1-4alkylamino; W is C(O), C(S), CH.sub.2 or is absent; Y is selected from CH.sub.2, SO.sub.2, SO, S, C(O), PO.sub.2 and NR.sub.4; Z is N or CH; X.sub.1 and X.sub.2 are each independently selected in each instance from hydrogen, halogen, nitro, cyano, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-4alkyl, hydroxy, SC.sub.1-4alkyl, OC.sub.1-4alkylamino, OH, pyrrolidine, piperidine, morpholine, piperazine, N-methylpiperazine; X.sub.3 is hydrogen, methyl, ethyl, isopropyl or benzyl; X.sub.4 and X.sub.5 are independently selected in each instance from hydrogen, C.sub.1-3alkyl, haloalkyl, halogen, cycloalkyl, amino, hydroxy, cyano, nitro; n is 0, 1, 2, 3, 4; or residues X.sub.3 and X.sub.4 taken together represent a single bond or a C.sub.1-4alkanediyl, said single bond or said C.sub.1-4alkanediyl forming together with the bridging atoms to which they are respectively linked a 5 or 6 membered heterocyclic ring; R.sub.1, R.sub.2, R.sub.2a and R.sub.3 are each independently selected from hydrogen, halogen, nitro, cyano, hydroxy, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-4alkyl, OC.sub.1-4alkylamino, SC.sub.1-4alkyl; R.sub.4 is selected from hydrogen, C.sub.1-4alkyl, C.sub.1-4aminoalkyl, C.sub.1-4hydroxyalkyl, C.sub.1-4nitroalkyl, C.sub.1-4thioalkyl, C.sub.1-6haloalkyl; Q is selected from C.sub.1-8 alkyl, C.sub.1-8 alkenyl, cycloalkyl, heterocycloalkyl, aryl ring, heteroaromatic ring, wherein: the C.sub.1-8 alkyl is optionally substituted with hydroxy, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, N(C.sub.1-4alkyl).sub.2, NH(CO)C.sub.1-4alkyl, aryl, heteroaryl, heterocycloalkyl, cycloalkyl, cycloalkenyl, each of said aryl, heteroaryl, heterocycloalkyl, cycloalkyl, cycloalkenyl being optionally substituted with methyl, halogen, hydroxy; the cycloalkyl and the heterocycloalkyl are each optionally substituted with OH, OSO.sub.2R.sub.5, C.sub.1-3alkyl, NR.sub.6R.sub.7, wherein: R.sub.5 is selected from hydrogen, phenyl, heteroaryl, aminophenyl and nitrophenyl; and wherein R.sub.6 and R.sub.7 are each independently selected from H, methyl, C(O)CH.sub.3, SO.sub.2CH.sub.3; the aryl ring or the heteroaromatic ring are each optionally substituted with one or more substituents selected from halogen, nitro, cyano, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NH.sub.2, NHSO.sub.2C.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-4alkyl, hydroxy, SC.sub.1-4alkyl, OC.sub.1-4alkylamino; and any stereoisomer, pharmaceutically acceptable salt, hydrate, solvate thereof, wherein said method comprises administering to said patient a pharmaceutical effective amount of said compound.

2. (canceled)

3. The method according to claim 1 wherein: A is benzene; and/or Y is SO.sub.2; and/or W is C(O) or CH.sub.2; and/or Z is N; and/or X.sub.4 and X.sub.5 are H.

4. The method according to claim 1, wherein the compound has general formula (II): ##STR00192##

5. The method according to claim 1, the compound being: ##STR00193## ##STR00194## ##STR00195## ##STR00196## ##STR00197## ##STR00198## ##STR00199## ##STR00200## ##STR00201## ##STR00202##

6. The method according to claim 1, the compound being: ##STR00203##

7. (canceled)

8. A compound of general Formula (III): ##STR00204## wherein A is a benzene ring or a five- or six heteroaromatic ring; B is a benzene ring of general structure: ##STR00205## wherein: R.sub.1, R.sub.2 and R.sub.3 are each independently selected from hydrogen, halogen, nitro, cyano, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-6alkyl, OC.sub.1-4alkylamino, hydroxy, SC.sub.1-4alkyl; R.sub.2a is hydrogen, CF.sub.3, F, OH, OC.sub.1-4alkyl, SC.sub.1-4alkyl, OC.sub.1-4alkylamino with the proviso that: if R.sub.2a is hydrogen or F, then R.sub.2 and R.sub.3 are each independently selected from F, Cl, Br, CF.sub.3, OMe, OH; or if R.sub.1 is halogen, then R.sub.2a is hydrogen and R.sub.2 and R.sub.3 are each independently selected from hydrogen, halogen, nitro, cyano, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-6alkyl, OC.sub.1-4alkylamino, hydroxy, SC.sub.1-4alkyl; or B is a five- or six membered heteroaromatic ring optionally substituted by one or more substituents each independently selected from hydrogen, halogen, nitro, cyano, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-6alkyl, hydroxy, SC.sub.1-4alkyl, OC.sub.1-4alkylamino; W is C(O); Y is selected from CH.sub.2, SO.sub.2, SO, S, C(O), PO.sub.2, and NR.sub.4; Z is N or CH; X.sub.1 and X.sub.2 are each independently selected in each instance from hydrogen, halogen, nitro, cyano, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-4alkyl, hydroxy, SC.sub.1-4alkyl, OC.sub.1-4alkylamino, OH, pyrrolidine, piperidine, morpholine, piperazine, N-methylpiperazine; X.sub.3 is hydrogen, methyl, ethyl, isopropyl or benzyl; X.sub.4 and X.sub.5 are independently selected in each instance from hydrogen, C.sub.1-3alkyl, haloalkyl, halogen, cycloalkyl, amino, hydroxy, cyano, nitro; n is 0, 1, 2, 3, 4; or residues X.sub.3 and X.sub.4 taken together represent a single bond or a C.sub.1-4alkanediyl, said single bond or said C.sub.1-4alkanediyl forming together with the bridging atoms to which they are respectively linked a 5 or 6 membered heterocyclic ring; R.sub.4 is selected from hydrogen, C.sub.1-4alkyl, C.sub.1-4aminoalkyl, C.sub.1-4hydroxyalkyl, C.sub.1-4nitroalkyl, C.sub.1-4thioalkyl, C.sub.1-6haloalkyl; Q is selected from C.sub.1-8 alkyl, C.sub.1-8 alkenyl, cycloalkyl, heterocycloalkyl, aryl ring, heteroaromatic ring, wherein: the C.sub.1-8 alkyls is optionally substituted with hydroxy, OC.sub.1-4alkyl, NHC.sub.1-4alkyl, N(C.sub.1-4alkyl).sub.2, NH(CO)C.sub.1-4alkyl, aryl, heteroaryl, heterocycloalkyl, cycloalkyl, cycloalkenyl, each of said aryl, heteroaryl, heterocycloalkyl, cycloalkyl, cycloalkenyl being optionally substituted with methyl, halogen, hydroxy; the cycloalkyl and the heterocycloalkyl are each optionally substituted with OH, OSO.sub.2R.sub.5, C.sub.1-3alkyl, NR.sub.6R.sub.7, wherein: R.sub.5 is selected from hydrogen, phenyl, heteroaryl, aminophenyl and nitrophenyl; and wherein R.sub.6 and R.sub.7 are each independently selected from H, methyl, C(O)CH.sub.3, SO.sub.2CH.sub.3; the aryl ring or the heteroaromatic ring are each optionally substituted with one or more substituents selected from halogen, nitro, cyano, thiol, C.sub.1-4alkyl, haloalkyl, O-haloalkyl, OC.sub.1-4alkyl, NH.sub.2, NHSO.sub.2C.sub.1-4alkyl, NHC.sub.1-4alkyl, C(O)C.sub.1-6alkyl, C(O)OC.sub.1-6alkyl, C(O)NHC.sub.1-4alkyl, hydroxy, SC.sub.1-4alkyl, OC.sub.1-4alkylamino; and any stereoisomer, pharmaceutically acceptable salt, hydrate, solvate thereof.

9. The compound of formula (III) according to claim 8 wherein: A is benzene; and/or Y is SO.sub.2; and/or Z is N; and/or X.sub.4 and X.sub.5 are H.

10. The compound of formula (III) according to claim 8 being: ##STR00206## ##STR00207## ##STR00208## ##STR00209## ##STR00210##

11.-12. (canceled)

13. The method according to claim 18, wherein said compound modulates activity of cellular prion protein (PrPC).

14. A pharmaceutical composition comprising at least one compound as defined in claim 8, alone or in combination with at least one further active compound, and at least one pharmaceutically acceptable excipient.

15. (canceled)

16. A process for the synthesis of a compound of general formula (III) according to claim 6, wherein A is benzene and Y is SO2, comprising the following steps: a) reacting a compound of formula 1a with an aromatic or heteroaromatic amine of formula 1b, in the presence of a solvent like dichlorometane and an amine like pyridine, trimethylamine, diethylisopropylamine, to give a compound of formula 2a ##STR00211## b) reducing the nitro group of compound of formula 2a to an amino group by hydrogenation in the presence of Raney-Nichel catalyst or with SnCl2.Math.2H2O under appropriate conditions, to obtain a compound of formula 3a: ##STR00212## c) converting compound 3a into a compound of formula 5a: ##STR00213## by a first step comprising reaction with NaNO.sub.2, NaOH and HCl under appropriate conditions, and a second step employing Cu powder and DMSO as solvent at room temperature; d) converting compound of formula 5a into a compound of formula (I) or of formula (II), wherein the reaction comprises at least one of the following step: reacting 5a with an alkylating agent of formula hal-(CH.sub.2).sub.nC(O)OEt or with an alkylating agent of formula hal-(CH.sub.2).sub.n-Q wherein hal is bromine or chlorine; treating with an amine of formula Q-NHX.sub.3 under microwawe irradiation and neat conditions; coupling with an amine of formula Q-NHX.sub.3 in the presence of a condensing agents such as TBTU in CH.sub.2Cl.sub.2 and DIPEA or using SOCl.sub.2 as chlorinating agent.

17. The method according to claim 1, wherein said neurodegenerative disease or said immune disease is selected from the group consisting of Alzheimer's Disease, Prion Disease, Multiple Sclerosis, Autoimmune Encephalitis, Parkinsons' Disease, Inflammatory Bowel Disease and Crohn's disease.

18. The method of claim 17, wherein said neurodegenerative disease is Prion Disease, provided that compound ##STR00214## is not included.

19. The compound of formula III according to claim 8 being: ##STR00215##

Description

BRIEF DESCRIPTION OF THE FIGURES

[0112] Embodiments and experiments illustrating the principles of the invention will be discussed with reference to the following figures:

[0113] FIG. 1. Chemical and biological characterization of SM3. The compound SM3 (referred to as LD24 in the original study.sup.21), structure shown in panel (A), was previously identified in a HTS screen for its ability to suppress the CR PrP-dependent hypersensitivity to cationic antibiotics in a dose-dependent fashion. (B) The drug-based cell assay (DBCA) was performed as previously described.sup.20,25. Briefly, HEK293 cells stably transfected with a toxic PrP mutant carrying a deletion in the central region of the protein (105-125) were seeded in 24-well plates and incubated in medium containing 500 g/mL of Zeocin, for 48 h at 37 C. Cell death in response to co-treatment with SM3 (0.1-10 M) was evaluated by MTT assay. Data are expressed as a percentage of untreated cells.

[0114] FIG. 2. Evaluation of potency for the SM3 derivatives. The graph shows the relative ability of each compound (tested at 1 M) to suppress the CR PrP-dependent hypersensitivity to cationic antibiotics. Data are expressed as the mean percentage relative to the parent compound SM3 (referred in the graph as LD24). Error bars reflect standard deviation. Each compound has been tested in at least three biologically independent replicates (n3).

[0115] FIG. 3. Dose-response analysis of selected compounds. (A) Chemical structures of the selected molecules are shown in panel. (B) A dose-response analysis using the DBCA was employed to evaluate the anti-CR PrP effects of the different molecules. The graphs show a quantification of the dose-dependent, rescuing effect of each molecule. Average values were obtained from a minimum of 3 independent experiments (n3), and expressed as a percentage of cell viability in untreated cells. Data were fitted to a sigmoidal function using a 4-parameter logistic (4PL) non-linear regression model, allowing the estimation of the half-maximal inhibitory concentration (IC.sub.50). (C) The intrinsic toxicity of each compound was evaluated in naive HEK293 cells, exposed to each molecule/concentration for 48 h at 37 C. Cytotoxicity was evaluated by MTT. Average values were obtained from a minimum of 3 independent experiments (n3), and expressed as a percentage of cell viability in untreated cells. Data were fitted to an inverse sigmoidal function using a 4PL non-linear regression model, allowing the estimation of the half-maximal toxicity dose (LD.sub.50).

[0116] FIG. 4. SM231 rescues neurotoxicity. Primary hippocampal neurons were exposed to different concentrations of A oligomers for short times (10, 20 or 60 minutes) or vehicle (VHC) control. We confirmed that the oligomers induce a quick, transient phosphorylation of the Fyn kinase (results at the 20 min time point are shown in panel A). Consistent with previous observations, this effect was prevented by co-treatment with a PrPC-directed compound TMPyP. Interestingly, co-incubation with SM231 completely abrogated A effects, restoring Fyn phosphorylation to normal levels. (B) Primary hippocampal neurons were incubated for 3 hours with A oligomers (3 M) or VHC control. Consistent with previous reports, we observed a decrease of several post-synaptic markers (indicated), as evaluated by western blotting of the triton X-insoluble fractions. Importantly, co-incubation with SM231 for 20 minutes prior to incubation with A oligomers significantly rescued the levels of all the post-synaptic markers. The level of a control protein (actin) was not affected by either A oligomers or SM231. (*p<0.05; ** p<0.01 by Student's t test).

[0117] FIG. 5. Metabolic studies on SM231. (A) The software MetaSite suggested three regions of the molecule as the main metabolic sites (red and yellow colours in the 3D structure and bold spheres indicated by empty arrows in 2D structure) with the methylene bridge predicted as the most reactive (highlighted in red/blue sphere and indicated by a solid black arrow in the 2D structure of SM231. (B) Docking experiments against the active site of CYP450 indicated that only the cyclohexyl moiety and the C-3 (gray arrows) could be metabolized because they were accessible to the hepatic metabolic enzymes. (C) Incubation (for 4 h) of SM231 with rat liver microsomes (RLM) indicated a t1/2 of 25 min (paned C at the right) and HPLC-MS analysis of the resulting mixture suggested four metabolites (MET1-4) confirming that the cyclohexyl and the C-3, at less extent, are the main metabolic sites.

[0118] FIG. 6. DBCA-based validation of newly developed derivatives. Chemical structures for each molecule are shown inside the graphs. A dose-response analysis using the DBCA was employed to evaluate the anti-CR PrP effects of the different molecules. The graphs show a quantification of the dose-dependent, rescuing effect of each molecule. Average values were obtained from a minimum of 3 independent experiments (n3), and expressed as a percentage of cell viability in untreated cells. Data were fitted to a sigmoidal function using a 4PL non-linear regression model, allowing the estimation of the half-maximal inhibitory concentration (IC.sub.50).

[0119] FIG. 7. SM884 rescue the suppression of LTP by a prion strain. The bar graph shows the quantification of the rescue effect on LTP induced by the chronic administration of SM884 to brain slices acutely treated with a lysate of cells infected with the mouse-adapted M1000 human prion strain. Values are expressed as mean+/SEM and calculated as percentage rescue of LTP over vehicle controls. Statistically significant differences between SM884-treated and untreated slices are calculated with student t-test: M1000 vs 884 0.03 M+M1000 p=0.0038 (**); M1000 vs 884 0.1 M+M1000 p=0.0031 (**). M1000 n=4; 884 0.03 M+M1000 n=4; 884 0.1 M+M1000 n=5.

[0120] FIG. 8. DC subsets express endogenous PrPC and DC2 treated with SM231 promote Treg cells in DC-T cell co-cultures. A. Sorted mouse DC1 and DC2 cells were treated with TMP or SM231 and then subjected to western blot analysis to evaluate PrPC expression using a specific anti-PrPC antibody. Results shown are meanS.D. from two independent EAE experiments. *P<0.05; two-tailed Mann-Whitney test. B. CD4+ LAP+FOXP3+ cell frequency in cultures of DCs (i.e. DC1 or DC2), preconditioned with TMP or SM231 or vehicle, treated with either a specific PrPC SiRNA or an SiRNA control, cultured with nave CD4+ T cells for 5 days. Representative results of CD4+CD25+LAP+FOXP3+ cell frequency (top right quadrants) in T: DC2 co-cultures Representative results from one experiment of three.

[0121] FIG. 9. Compounds SM888 and SM889 promote tolerogenic activity in cDC2. cDC2 treated overnight with different concentrations of PrPC modulating molecules or vehicle as control, were co-cultured with CFSE-labeled CD4+ T cells, from the spleen of OT.II mice, in the presence of different concentrations of OVA. After 3 days, proliferation was analyzed by FACS to evaluate the % of T cell proliferation in response to the specific antigen. Data are shown as meanS.D. **P<0.01, ***P<0.001, ****P<0.0001, ANOVA followed by Bonferroni multiple comparison test.

[0122] FIG. 10. Administration of the reference PrPC binding molecule TMP or of a PrPC activating molecule SM231 ameliorate EAE severity. A. Scheme of EAE induction and treatment. B EAE clinical scores (SEM) of) mice on a C57BL/6 background, treated with different doses of SM 231 (*P<0.05; **P<0.01; ***P<0.001; Student's ttest). C. Representative staining of spinal cord sections from MOG 35-55-immunized mice treated with PBS or SM231, visualizing immune infiltrates and demyelinization at day 25 post immunization in mice treated with PBS or SM231.

[0123] FIG. 11. SM231 does not act directly on PrPC. (A) SM231 does not alter the cell-surface localization of PrPC. HEK293 cells stably expressing an EGFP-tagged version of PrPC were grown to 60% confluence on glass coverslips, and then treated with the indicated concentrations of SM231 or CPZ for 24 h. After fixation and washing, the intrinsic green signal of EGFP-PrPC was acquired with an inverted microscope coupled with a high-resolution camera equipped with a 488 nm excitation filter. (B) SM231 does not alter the expression of PrPC. HEK293 cells expressing WT PrPC were treated with SM231 at different concentrations (indicated), for 48 hours. Total PrP levels were evaluated in whole-cell lysates by Western blot, using anti-PrP antibody D18. The picture in the upper panel illustrates a representative western blotting. Graph in the bottom panel shows the quantification of PrP levels, obtained by densitometric analysis of four independent (n=4) experiments, normalizing each value on the corresponding Ponceau S-stained lane. Bars represent the mean (SEM), expressed as percentage of the levels in untreated cells. (C) SM231 does not bind to PrPC. The interaction of the porphyrin Fe(III)-TMPyP (abbreviated TP), chlorpromazine (CPZ) or SM231 with recombinant PrPC was evaluated by DMR. Different concentrations of each compound (0.1-1000 M) were added to label-free microplate well surfaces (EnSpire-LFB HS microplate, Perkin Elmer) on which full-length human recombinant PrPC or BSA had previously been immobilized. Measurements were performed before (baseline) and after (final) adding the compound. The response (pm) was obtained subtracting the baseline output to the final output signals. The output signal for each well was obtained by subtracting the signal of the protein-coated reference area to the signal of uncoated area. Signals for TP (blue dots) or CPZ (green dots) were fitted (blue and green lines) to a sigmoidal function using a 4PL non-linear regression model; R.sup.2=0.99; p=0.00061. Conversely, no binding was detected for SM231, suggesting that this compound does not exert its effects by directly binding to PrPC.

[0124] FIG. 12. An FXR agonist potently rescues mutant PrP toxicity. The DBCA was employed to evaluate the ability of the two FXR agonists, tested at different concentrations (indicated), to rescue the Zeocin hypersensitivity conferred by the expression of mouse CR PrP molecules expressed in HEK293 cells. Bar graphs illustrate the quantification of the dose-dependent rescuing effect of each molecule. Mean values were obtained from a minimum of 3 independent cell culture preparations, and expressed as percentage of cell viability rescue, using the following equation: R=(TZ)/(UZ) (R: rescuing effect; T: cell viability in compound-treated samples; Z: cell viability in zeocin-treated samples; U: cell viability in untreated samples).

[0125] FIG. 13. FXR transcriptional activity in hepatocytes treated with SM231. Murine hepatocytes were treated for 4 or 12 h, as indicated. FXR and Nr0b2 mRNA levels were assessed by RT-qPCR. mRNA levels in untreated cells were arbitrarily set to 1.

MATERIALS AND METHODS

Chemistry: Methods for Making the Compounds of General Formula (I)

[0126] As used herein, the following abbreviations have the following meanings. If an abbreviation is not defined, it has its generally accepted meaning.

Abbreviations

[0127] BOP: N-(Benzenesulfonyl)-L-prolyl-L-O-(1-pyrrolidinylcarbonyl)tyrosine sodium salt; DIPEA: N,N-Diisopropylethylamine; DMF: N,N-Dimethylformamide; DMSO: N,N-dimethylsulfoxide; EtOAc: ethyl acetate; MeOH: methanol; TBTU: 2-(1H-Benzotriazole-1-yl)-1,1,3,3-tetramethylaminium tetrafluoroborate; Pyr: Pyridine;

[0128] Unless otherwise indicated, reagents and solvents were purchased from common commercial suppliers and were used as such. HPLC-grade solvents used for IPLC analysis were purchased by Sigma-Aldrich and all the employed mobile phases were degassed with 10 min sonication before use. Organic solutions were dried over anhydrous Na.sub.2SO.sub.4 and concentrated with a rotary evaporator at low pressure. All reactions were routinely checked by thin-layer chromatography (TLC) on silica gel 60F254 (Merck) and visualized by using UV or iodine. Microwave assisted reactions were carried out using the microwave reactor Biotage Initiator 2.0 and parameters were adjusted according to the reaction as indicated in the following examples. Flash chromatography on Merck silica gel 60 (mesh 230-400). Melting points were determined in capillary tubes (Bchi Electrotermal model 9100) and are uncorrected. .sup.1H NMR spectra were recorded at 200 or 400 MHz (Bruker Avance DRX-200 or 400, respectively) while .sup.13C NMR spectra were recorded at 100 MHz (Bruker Avance DRX-400) as well as 2D .sup.1H NMR NOESY run in phase sensitive mode. Chemical shifts are given in ppm () relative to TMS. Spectra were acquired at 298 K. Data processing was performed with standard Bruker software XwinNMR and the spectral data are consistent with the assigned structures. Yields were of purified products and were not optimized. All compounds were 95% pure as determined by LC/MS using an Agilent 1290 Infinity System machine equipped with DAD detector from 190 to 640 nm. The purity was revealed at 270.44 nm using a ZORBAX Eclipse Plus C18 (2.150 mm, 1.8 M particle size column) reverse phase was used with gradient of 0-100% CH.sub.3CN with 0.1% formic acid (channel B) in water with 0.1% formic acid (channel A) for 20 min at 0.3 mL/min. Injection volume was 0.5 L with a column temperature of 50 C. All compounds were 95% pure as determined by HPLC using a Waters System machine equipped with UV detector. The purity was revealed at 254 and 270 nm by using an X Terra C18 (x mm, M particle size column) reverse phase was used with isocratic eluent 70:30 of CH.sub.3CN (channel C) and water with 0.1% formic acid (channel B) for 10 min at 1 mL/min. Injection volume was 20 L with a column temperature of 25 C. Peak retention time is given in minutes. HRMS Detection was based on electrospray ionization (ESI) in negative polarity using Agilent 1290 Infinity System equipped with a MS detector Agilent 6540UHD Accurate Mass Q-TOF.

[0129] The compounds of the invention can be prepared while using a series of chemical reactions well known to those skilled in the art, altogether making up the process for preparing said compounds and exemplified further. The processes described further are only meant as examples and by no means are meant to limit the scope of the present invention. In particular, the compounds of the present invention may be prepared according to the general procedure outlined in the following Schemes 1, 2, 3 and 4. Alternative synthetic pathways and analogues structures will be apparent to those skilled in the art of organic chemistry.

[0130] Scheme 1 shows a procedure useful for making heterocyclic compounds of formula (I) having a dibenzo[c,e][1,2]thiazine 5,5 dioxide scaffold, i.e. wherein A is a phenyl, B is a phenyl, Y is a SO.sub.2 group, and wherein W is carbonyl, Z is nitrogen, X.sub.4 and X.sub.5 are hydrogen, n is as defined for general formula (I). The Q substituent can be selected from those described in general formula (I).

##STR00031##

[0131] Coupling reaction of an appropriate 2-nitro-benzensulfonyl chloride of formula (1a) with unsubstituted or functionalized aniline, carried-out at 40 C. in dry pyridine, affords the corresponding aryl 2-nitrobenzensulfonamides of formula (2a), in high yields. The nitro group of intermediates of formula (2a) was reduced by using a catalytic reduction employing Raney-Ni and H.sub.2 flux or SnCl.sub.2.Math.2H.sub.2O in acidic conditions, depending on the substrates, to afford amino compounds of formula (3a) which were subsequently diazotized using NaNO.sub.2 and HCl followed by addition of NaOH promoting in situ conversion of diazo compounds into unstable intermediates of formula (4a). These latter were immediately isolated as crude products and converted to intermediates of formula (5a) in moderate yields, employing Cu powder and DMSO as solvent at room temperature. Compounds of formula (5a) were reacted with ethyl 2-bromoacetate, under microwave irradiation at 50 C. for 15 min. in DMF and using DIPEA as scavenger to afford compounds of formula (6a) in good yields. Some intermediates of formula (5a) were alkylated exploiting a Mitsunobu reaction to give certain compounds of formula (6a). Some examples of intermediates of formula (6a) were treated with an excess of amines as defined by Q substituents, employing microwaves irradiation at 120 C. and neat conditions to give target compounds of formula (8a). In some cases, intermediates of formula (7a) were treated with a mixture of 10% aq. NaOH and EtOH (1:1 ratio) to afford the corresponding carboxylic acids of formula (7a) which were coupled with aryl amines or alkyl amines, as defined by the Q substituent, and exploiting two different methods that entails the use of condensing agents such as TBTU in CH.sub.2Cl.sub.2 and using DIPEA as scavenger or the use of SOCl.sub.2 as chlorinating agent followed by the addition of amines to give other examples of target compounds of formula (8a). In some examples, di-substituted anilines were used to prepare intermediates of formula (5a) as mixture of regioisomers that were used as it is for the next reaction steps to obtain certain compounds of formula (8a); regioisomers were then separated into final compounds by flash chromatography to afford each pure regioisomer.

[0132] Scheme 2 shows a procedure useful for making heterocyclic compounds of formula (I) having a dibenzo[c,e][1,2]thiazine 5,5 dioxide scaffold wherein A is a phenyl, B is a phenyl, Y is a SO.sub.2 group, W is absent, Z is nitrogen, X.sub.4 and X.sub.5 are hydrogen, n is as defined for general formula (I). The Q substituent can be selected from those described in general formula (I).

Scheme 2. Synthetic Procedure for the Preparation of Some Target Compounds.

[0133] ##STR00032##

[0134] Certain compounds of formula (5a) were alkylated using bromo/chloroalkyls wherein Z was chosen between those substituents reported in formula (I) and with n=1, 2, 3, 4 by using the appropriate dihalide under microwave irradiation at 80 C. and using DIPEA as scavenger. Scheme 3 shows a procedure for synthesizing compounds SM226 and SM230 starting from a compound SM225 which was demethylated employing BBr.sub.3 in CH.sub.2Cl.sub.2 and added at 60 C. The reaction was then maintained at 30 C. to give the hydroxyl derivative SM226 used as intermediate for a successive O-alkylation using (2-chloroethyl)dimethylamine hydrochloride and Cs.sub.2CO.sub.3 in DMF at 80 C. to give the target compound SM230.

##STR00033##

[0135] Scheme 4 depict an example of compound of formula (I) wherein A is a phenyl, B is a 3-methyl-pyrazole, Y is a SO.sub.2 group and W is carbonyl and the Q substituent can be selected from those indicated in the formula (I).

##STR00034##

[0136] Compound 11a, reported in a Korean patent KR2011060653, was reacted with cyclohexylamine by using TBTU as condensing agent in presence of DIPEA affording intermediate 12a in good yield which was then condensed with hydrazine monohydrate in neat conditions at 60 C. giving the target product SM879.

[0137] The following examples are provided for the purpose of illustrating the present invention and by no means should be interpreted to limit the scope of the present invention.

TABLE-US-00001 TABLE 1 List of target compounds prepared in this invention - reference compound SM3 is included Compound Chemical structure of Experimental Code compound of formula 8a procedure Example SM3 [00035] 48 SM4 [00036] 49 SM5 [00037] 50 SM6 [00038] 67 SM7 [00039] 62 SM8 [00040] 68 SM9 [00041] 45 SM10 [00042] 51 SM11 [00043] 46 SM225 [00044] 55 SM226 [00045] 63 SM227 [00046] 56 SM228 [00047] 57 SM229 [00048] 57 SM230 [00049] 64 SM231 [00050] 53 SM254 [00051] 52 SM336 [00052] 60 SM337 [00053] 60 SM338 [00054] 59 SM339 [00055] 59 SM340 [00056] 54 SM585 [00057] 58 SM586 [00058] 58 SM587 [00059] 61 SM588 [00060] 78 SM882 [00061] 70 SM883 [00062] 70 SM884 [00063] 71 SM885 [00064] 72 SM881 [00065] 73 SM589 [00066] 79 SM655 [00067] 77 SM656 [00068] 80 SM880 [00069] 74 SM879 [00070] 82 SM886 [00071] 83 SM887 [00072] 84 SM888 [00073] 85 SM889 [00074] 86 SM890 [00075] 88 SM891 [00076] 89 SM892 [00077] 90

[0138] The following examples are compounds purchased by AMBINTER and tested as it is for their biological activities. The synthetic procedures reported in schemes 1-3 can be easily adapted to prepare commercially available compounds whose synthesis has not been reported yet.

TABLE-US-00002 TABLE 2 List of target compounds of general formula 8a purchased from commercial sources. SM162 COM129 [00078] SM163 COM130 [00079] SM164 COM131 [00080] SM165 COM132 [00081] SM166 COM133 [00082] SM167 COM134 [00083] SM168 COM135 [00084] SM169 COM136 [00085] SM170 COM137 [00086] SM171 COM138 [00087] SM172 COM139 [00088] SM173 COM140 [00089] SM174 COM141 [00090] SM175 COM142 [00091] SM176 COM143 [00092] SM177 COM144 [00093] SM178 COM145 [00094] SM179 COM146 [00095] SM180 COM147 [00096] SM181 COM148 [00097] SM219 COM149 [00098] SM220 COM150 [00099] SM221 COM151 [00100] SM222 COM152 [00101] SM223 COM153 [00102] SM224 COM154 [00103]

Experimental

[0139] General procedure to obtain nitrobenzensulfonam ides of formula 2a (Scheme 1): To a solution of commercial or synthesized 2-nitrobenzenesulfonyl chloride (1 equiv.) and the appropriate aniline (2 equiv.) in CH.sub.2Cl.sub.2, pyridine (1 equiv.) was added at once and the mixture was maintained under magnetic stirring at 30 C. for 2 h. After concentration to one third volume, the mixture was poured into ice-water and acidified with 2N HCl (pH=3) and after digestion under magnetic stirring a precipitate was formed. After filtration the crude was then triturated with cyclohexane/EtOAc (8:2) and filtered again to give benzensulfonamides of formula 2a.

Example 1

[0140] 2-nitro-N-[3-(trifluoromethyl)phenyl]benzenesulfonamide: Following the above general procedure and using 3-trifluoromethylaniline the compound was obtained in 93% yield as red solid: mp 132.6-132.7 C.; .sup.1H NMR (200 MHz, acetone-d.sub.6): 9.40 (brs, 1H, NH), 8.10-7.75 (m, 4H, ArH), 7.60-7.30 (m, 4H, ArH).

Example 2

[0141] N-(3-chloro-4-fluorophenyl)-2-nitrobenzenesulfonamide: Following the above general procedure and using 3-chloro-4-fluoroaniline the compound was obtained as red solid in 90% yield: mp 110.0-110.1 C.; .sup.1H NMR (200 MHz, acetone-d.sub.6): 9.25 (brs, 1H, NH), 8.00-7.70 (m, 4H, ArH), 7.50-7.40 (m, 1H, ArH), 7.30-7.20 (m, 2H, ArH).

Example 3

[0142] N-(3,5-dichlorophenyl)-2-nitrobenzenesulfonamide: Following the general procedure above reported and using 3,4-dichloroaniline, the compound was obtained as red solid in 95% yield: mp 128.0-129.0 C.; .sup.1H NMR (400 MHz, acetone-d.sub.6): 9.55 (brs, 1H, NH), 8.20 (d, J=1.3 and 7.8 Hz, 1H, ArH), 8.10-7.80 (m, 3H, ArH), 7.40-7.35 (m, 2H, ArH), 7.28 (t, J=1.8 Hz, 1H, ArH).

Example 4

[0143] 5-Fluoro-2-nitro-N-[4-(trifluoromethyl)phenyl]benzenesulfonamide (2a(Int-1)): Following the general procedure reported above, intermediate 5-fluoro-2-nitrobenzenesulfonyl chloride (prepared as reported in Buhr, WO 212110603) was reacted with commercial 3-trifluoromethylaniline to give the compound as red solid in 86% yield: m.p 130-132 C.; .sup.1H NMR (400 MHz, CDCl.sub.3): 7.30-7.40 (m, 3H, ArH), 7.50-7.60 (m, 3H, ArH and NH), 7.70 (dd, J=2.8 and 7.7 Hz, 1H, ArH), 7.90 (dd, J=4.5 and 8.8 Hz, 1H, ArH).

Example 5

[0144] N-(4-bromophenyl)-2-nitrobenzenesulfonamide: the intermediate was prepared following the procedure reported by Kurkin, A. et al. in Tetrahedron: Asymmetry, 2009, 20, 1500-1505. Melting point and spectral data are in agreement with those reported in literature.

Example 6

[0145] N-(3-bromophenyl)-2-nitrobenzenesulfonamide: the intermediate was prepared following the procedure reported by Abramovitch, R. A. et al. in J. Org. Chem. 1977, 42, 2914-2919. Melting point and spectral data are in agreement with those reported in literature.

Example 7

[0146] 2-nitro-N-[4-(trifluoromethyl)phenyl]benzenesulfonamide: the intermediate was prepared following the procedure reported by Kang, J. G. et al. in Biosci. Biotechnol. Biochem. 2002, 66, 2677-2682. Melting point and spectral data are in agreement with those reported in literature.

Example 8

[0147] N-[4-(methylthio)phenyl]-2-nitrobenzenesulfonamide: the intermediate was prepared following the procedure reported in PCT WO 2007/003962 A2. Melting point and spectral data are in agreement with those reported in literature.

Example 9

Scheme 5. Synthetic Procedure for the Preparation of Intermediate of Formula 2a(Int-2).

##STR00104##

[0148] 5-Methoxy-2-nitro-N-[4-(trifluoromethyl)phenyl]benzenesulfonamide (2a(Int-2)). A stirred mixture of 5-fluoro-2-nitro-N-[4-(trifluoromethyl)phenyl]benzenesulfonamide 2a(Int-1) (1.00 g, 2.86 mmol) in aqueous 10% NaOH (20 mL) and MeOH (40 mL) was kept at room temperature for 3 h. The reaction mixture was poured into ice/water and the formed precipitate was filtered off to give the title compound as a white solid in 99% yield: m.p. 142-144 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 3.89 (s, 3H, OCH.sub.3), 7.12 (dd, J=2.7 and 8.9 Hz, 1H, H-4), 7.37 (d, J=8.4 Hz, 2H, H-2 and H-6), 7.48 (d, J=2.7 Hz, 1H, H-6), 7.58 (d, J=8.5 Hz, 2H, H-3 and H-5), 8.02 (d, J=9.0 Hz, 1H, H-3).

[0149] General procedure to obtain aminobenzensulfonamides of formula 3a (Scheme 1): A stirred solution of nitro derivative of formula (2a) (1 equiv.) in EtOH (150 mL) was hydrogenated over a catalytic amount of Raney nickel at room temperature and atmospheric pressure for 2.5 h. The mixture was then filtered over Celite and the filtrate was evaporated to dryness to give the amino derivative pure by TLC (CHCl.sub.3/MeOH 98:2).

Example 10

[0150] 2-amino-N-[3-(trifluoromethyl)phenyl]benzenesulfonamide: Following the general procedure reported above, the compound was obtained in 96% yield as a whitish solid: mp 88.1-88.2 C. (dec.); .sup.1H NMR (200 MHz, acetone-d.sub.6): 9.50 (bs, 1H, NH), 7.60-7.25 (m, 5H, ArH), 7.25-7.15 (m, 1H, ArH), 6.75 (d, J=8.3 Hz, 1H, ArH), 6.50 (t, J=8.0 Hz, 1H, ArH), 6.75 (bs, 2H, NH.sub.2).

Example 11

[0151] 2-amino-N-(3-chloro-4-fluorophenyl)benzenesulfonamide: Following the procedure reported above, the compound was obtained as a grey solid, in 95% yield: mp 102.1-102.2 C.; .sup.1H NMR (200 MHz, acetone-d.sub.6): 9.15 (bs, 1H, NH), 7.40 (dd, J=1.6 and 8.0 Hz, 1H, ArH), 7.25-7.00 (m, 4H, ArH), 6.75 (d, J=8.3 Hz, 1H, ArH), 6.55 (t, J=8.0 Hz, 1H, ArH), 5.60 (bs, 2H, NH.sub.2).

Example 12

[0152] 2-amino-N-(3,5-dichlorophenyl)benzenesulfonamide: Following the procedure reported above, the compound was obtained as a grey solid, in 92% yield: mp 103.0-105.0 C.; .sup.1H NMR (400 MHz, acetone-d.sub.6): 9.50 (brs, 1H, NH), 7.59 (dd, J=1.5 and 7.9 Hz, 1H, ArH), 7.25 (dt, J=1.5 and 7.0 Hz, 1H, ArH), 7.18-7.12 (m, 2H, ArH), 7.10 (t, J=2.4 Hz, 1H, ArH), 6.85 (dd, J=0.9 and 7.9 Hz, 1H, ArH), 6.68 (dt, J=0.9 and 7.0 Hz, 1H, ArH), 5.65 (brs, 2H, NH.sub.2).

Example 13

[0153] 2-amino-N-[4-(trifluoromethyl)phenyl]benzenesulfonamide: Following the procedure reported above, the compound was obtained as a grey solid, in 85% yield (reaction time 1.5 h): mp 105.3-105.4 C.; .sup.1H NMR (200 MHz, DMSO-d.sub.6): 10.75 (bs, 1H, NH), 7.40-7.60 (m, 3H, ArH), 7.20-7.00 (m, 3H, ArH), 6.70 (d, J=8.0 Hz, 1H, ArH), 6.50 (t, J=8.0 Hz, 1H, ArH), 5.95 (bs, 2H, NH.sub.2).

Example 14

[0154] 2-amino-N-[4-(methylthio)phenyl]benzenesulfonamide: To a stirred suspension of the corresponding nitro derivative of formula 2a (0.20 g, 0.62 mmol) in 8N HCl (9.0 mL), SnCl.sub.2 2H.sub.2O (0.42 g, 1.85 mmol), dissolved in 8N HCl (2.0 mL), was added at once and the mixture was refluxed for 2 h. 10% NaOH was added to reach pH 6 and the precipitate so obtained was filtered and washed three time with CHCl.sub.3 (315 mL). The fractions were collected and the solvent was dried and evaporated to dryness to obtain the amino derivative (0.10 g, 50% yield) as a crude solid used as it is in the next reaction step: mp 94.1-94.3 C.; .sup.1H NMR (200 MHz, CDCl.sub.3): 7.40 (dd, J=1.5 and 8.0 Hz, 1H, ArH), 7.27-7.20 (m, 1H, ArH), 6.75 (d, J=8.3 Hz, 1H, ArH), 7.10-6.90 (m, 2H, ArH), 6.80-6.90 (m, 2H, ArH), 6.75-6.55 (m, 3H, ArH and NH), 4.75 (bs, 2H, NH.sub.2).

Example 15

[0155] 2-Amino-5-fluoro-N-[4-(trifluoromethyl)phenyl]benzenesulfonamide: Following the procedure reported above, the compound was obtained as pale orange solid in 87% yield (reaction time 1 h, purification method: trituration by cyclohexane): m.p 115-117 C.; .sup.1H NMR (400 MHz, CDCl.sub.3): 4.60 (bs, 2H, NH.sub.2), 6.70 (dd, J=4.3 and 8.8 Hz, 1H, ArH), 7.05 (dt, J=2.9 and 8.7 Hz, 1H, ArH), 7.15 (d, J=8.4 Hz, 2H, ArH), 7.30 (dd, J=2.9 and 7.9 Hz, 1H, ArH), 7.45 (d, J=8.4 Hz, 2H, ArH).

Example 16

[0156] 2-amino-N-(3-bromophenyl)benzenesulfonamide: the intermediate was prepared following the procedure reported by Abramovitch, R. A. et al. in J. Org. Chem. 1977, 42, 2914-2919. Melting point and spectral data are in agreement with those reported in literature.

Example 17

[0157] 2-amino-N-(4-methoxyphenyl)benzenesulfonamide: the intermediate was prepared following the procedure reported by Ramirez-Martinez, J. F. et al. in Molecules, 2013, 18, 894-913. Spectral data are in agreement with those reported in literature.

Example 18

[0158] 2-amino-N-(4-chlorophenyl)benzenesulfonamide: the intermediate was prepared following the procedure reported by Ramirez-Martinez, J. F. et al. in Molecules, 2013, 18, 894-913. Spectral data are in agreement with those reported in literature.

Example 19

[0159] 2-amino-N-(2-bromophenyl)benzenesulfonamide: the intermediate was prepared following the procedure reported by Giannotti, D. et al. in J. Med. Chem. 1991, 34, 1356-1362. Spectral data are in agreement with those reported in literature.

Example 20

[0160] 2-amino-N-(3-chlorophenyl)benzenesulfonamide: the intermediate was prepared following the procedure reported in PCT WO 96/05185. Melting point and spectral data are in agreement with those reported in literature.

Example 21

[0161] 2-amino-N-(4-bromophenyl)benzenesulfonamide: the intermediate was prepared following the procedure reported by Ramirez-Martinez, J. F. et al. in Molecules, 2013, 18, 894-913. Spectral data are in agreement with those reported in literature.

Example 22

[0162] 2-Amino-5-methoxy-N-[4-(trifluoromethyl)phenyl]benzenesulfonamide. Following the procedure reported above, the compound was obtained as a brown solid in 73% yield (reaction time 12 h, purification method: trituration by Et.sub.2O): m.p. 150-152 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 3.64 (s, 3H, OCH.sub.3), 5.38 (bs, 2H, NH.sub.2), 6.52 (d, J=8.4 Hz, 1H, H-3), 6.66-6.69 (m, 1H, H-4), 6.82 (d, J=8.0 Hz, 2H, H-2 and H-6), 7.15-7.21 (m, 3H, H-6, H-3 and H-5), 7.97 (s, 1H, NH).

[0163] General procedure to obtain 6H-dibenzo[c,e][1,2]thiazine 5,5-dioxides of formula 5a (Scheme 1): Aminobenzenesulfonamide of formula 3a (1 equiv.), NaOH (1.2 equiv.) and NaNO.sub.2 (1.2 equiv.) were mixed in water and the obtained solution was added dropwise to HCl 37% (6 equiv.) and kept to 0 C. The muddy mixture was mixed with a glass rod for 30 min verifying the formation of diazonium salt by the -naphtol assay. The red mixture was than diluted with H.sub.2O and treated with AcONa powder till pH=5 and the orange solid so obtained was filtered and treated with cyclohexane to obtain instable crude solid of formula 4a. Due to its high instability, the solid was immediately added portion wise to a stirring suspension of Cu (5% of mass weight) powder in DMSO. After 30 min. the reaction mixture was filtered over Celite to remove the Cu powder and the filtrate was poured into ice/water acidifying with HCl 2N till pH=4 to afford a precipitate that was filtered under vacuum to give intermediates compounds of formula 5a.

Example 23

[0164] 9-bromo-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a, the compound was obtained in 70% yield as brown solid and used as it is in the next reaction step: mp 229-231 C. .sup.1H NMR (200 MHz, DMSO-d.sub.6):511.50 (bs, 1H, NH), 8.37 (d, J=2.3 Hz, 1H, ArH), 8.25 (d, J=7.6 Hz, 1H, ArH), 7.90 (dd, J=1.3 and 7.7 Hz, 1H, ArH), 7.76 (dt, J=1.4 and 7.5 Hz, 1H, ArH), 7.66 (dd, J=1.1 and 7.5 Hz, 1H, ArH), 7.59 (dd, J=2.1 and 8.6 Hz, 1H, ArH), 7.55-7.80 (m, 3H, H-2, H-3 and H-8), 7.10 (d, J=8.6 Hz, 1H, H-7).

Example 24

[0165] 9-chloro-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a, the compound was obtained, after purification by flash column chromatography (CHCl.sub.3/MeOH 98:2), as a brown solid in 26% yield (reaction time 2 h): mp 231.4-231.5 C.; .sup.1H NMR (200 MHz, DMSO-d.sub.6): 11.50 (bs, 1H, NH), 8.29-8.25 (m, 2H, ArH), 7.89 (dd, J=1.5 and 7.5 Hz, 1H, ArH), 7.75 (dt, J=1.5 and 7.5 Hz, 1H, ArH), 7.62 (dt, J=1.0 and 9.0 Hz, 1H, ArH), 7.48 (dd, J=2.3 and 7.2 Hz, 1H, ArH).

Example 25

[0166] 9-(Trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a, the compound was obtained as a brown solid in 66% yield (reaction time 1 h): mp 235-237 C. .sup.1H-NMR (200 MHz, CDCl.sub.3): 8.22 (brs, 1H, ArH), 8.03-7.98 (m, 2H, ArH), 7.80-7.74 (m, 2H, Ar.H), 7.64-7.57 (m, 2H, ArH), 7.20 (brs, 1H, NH).

Example 26

[0167] 9-(Methylthio)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a the compound was obtained, after purification by flash column chromatography (CH.sub.2Cl.sub.2/MeOH 98: 2), as a pale brown solid in 25% yield (reaction time 2 h): mp 211.4-211.6 C.; .sup.1H-NMR (200 M Hz, DMSO-d.sub.6): 11.29 (brs, 1H, NH), 8.25 (d, J=7.9 Hz, 1H, ArH), 8.00 (brs, 1H, ArH), 7.87 (d, J=7.7 Hz, 1H, ArH), 7.85 (t, J=7.3 Hz, 1H, ArH), 7.61 (t, J=7.4 Hz, 1H, ArH), 7.34 (d, J=8.5 Hz, 1H, ArH), 7.09 (d, J=8.5 Hz, 1H, ArH).

Example 27

[0168] 9-Methoxy-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a the compound was obtained, after purification by flash column chromatography (CHCl.sub.3/MeOH 97:3), as pale brown solid in 41% yield (reaction time: 30 min.): mp 198-202 C. .sup.1H-NMR (200 MHz, DMSO-d.sub.6) 10.97 (brs, 1H, NH), 8.25 (d, J=7.7 Hz, 1H, ArH), 7.85 (dd, J=1.4 and 7.7 Hz, 1H, ArH), 7.75 (dt, J=1.4 and 7.55 Hz, 1H, ArH), 7.68-7.55 (m, 2H, ArH), 7.13-6.95 (m, 2H, ArH), 3.80 (s, 3H, CH.sub.3).

Example 28

[0169] 7-Bromo-6H-dibenzo-[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a the compound was obtained as yellow solid in 78% yield: mp 188.2-188.4 C. (dec.). .sup.1H-NMR (400 MHz, DMSO-d.sub.6): 10.80 (brs, 1H, NH), 8.25-8.30 (m, 2H, ArH), 7.95 (d, J=7.7 Hz, 1H, ArH), 7.85-7.80 (m, 2H, ArH), 7.72 (t, J=7.5 Hz, 1H, ArH), 7.36 (t, J=7.9, 1H, ArH).

Example 29

[0170] 8,10-Dichloro-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a the compound was obtained as yellow solid in 77% yield: mp 190.0-191.0 C. (dec.); .sup.1H-NMR (200 MHz, acetone-d.sub.6): 10.25 (brs, 1H, NH), 8.58 (dd, J=1.7 and 7.8 Hz, 1H, ArH), 7.95 (dd, J=1.5 and 7.3 Hz, 1H, ArH), 7.83-7.65 (m, 2H, ArH), 7.48 (d, J=2.1 Hz, 1H, ArH), 7.32 (J=2.1 Hz, 1H, ArH).

Example 30

[0171] 3-Fluoro-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a the compound was obtained as pale brown solid in 83% yield: m.p. 195-197 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.35 (d, J=8.4 Hz, 1H, H-7), 7.70 (dt, J=2.7 and 8.7 Hz, 1H, H-2), 7.80 (d, J=8.5 Hz, 1H, H-8), 7.85 (dd, J=2.6 and 7.6 Hz, 1H, H-4), 8.50 (dd, J=4.8 and 8.9 Hz, 1H, H-1), 8.55 (s, 1H, H-10), 12.10 (bs, 1H, NH).

Example 31

[0172] 8-bromo-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide and 10-bromo-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: Following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a, a mixture of two regioisomers difficult to be separated was obtained and the crude was employed without further purification for the next reaction step.

Example 32

[0173] 8-chloro-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide and 10-chloro-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a, a mixture of two regioisomers difficult to be separated was obtained and the crude was employed without further purification for the next reaction step.

Example 33

[0174] 8-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide and 10-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a, a mixture of two regioisomers difficult to be separated was obtained and the crude was employed without further purification for the next reaction step.

Example 34

[0175] 8-Chloro-9-fluoro-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide and 10-chloro-9-fluoro-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a, a mixture of two regioisomers difficult to be separated was obtained and the crude was employed without further purification for the next reaction step.

Example 35

[0176] 3-Methoxy-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide: following the general procedure reported above and starting from the corresponding amino-benzensulfonamide of formula 3a, the compound was obtained in 40% yield as brown solid: m.p. 198-200 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 3.84 (s, 3H, OCH.sub.3), 7.30-7.43 (m, 3H, ArH), 7.75 (d, J=7.2 Hz, 1H, ArH), 8.37 (d, J=8.6 Hz, 1H, ArH), 8.49 (s, 1H, ArH), 11.78 (s, 1H, NH).

[0177] General procedure to obtain 6H-dibenzo[c,e][1,2]thiazine 5,5-dioxides N-6 ethyl acetates of formula 6a (Scheme 1): In a microwave reactor tube, a solution of the appropriate compound of formula 5a (1 equiv.), ethyl bromoacetate (1 equiv.), and DIPEA (3 equiv.) in dry DMF (5 mL) was irradiated at 50 C. for 15 min. by setting the following experimental parameters: pressure 5 bar, cooling off, FHT on, solvent absorption very high. The pitchy mixture was poured into ice-water and extracted three times with EtOAc. The combined organic layers were washed with brine, dried, and evaporated to dryness to give a crude slurry mass that was triturated with EtOH giving a precipitate that was filtered to afford the desired compound.

Example 36

[0178] Ethyl 2-(9-bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, the compound was obtained as pink solid in 75% yield: mp 89-91 C. .sup.1H-NMR (200 MHz, DMSO-d.sub.6): 8.40 (d, J=2.3 Hz, 1H, ArH), 8.26 (d, J=7.6 Hz, 1H, ArH), 7.90-7.60 (m, 4H, ArH), 7.40 (d, J=8.6 Hz, 1H, ArH), 4.77 (s, 2H, NCH.sub.2), 3.90 (q, J=7.0 Hz, 2H, OCH.sub.2CH.sub.3), 0.80 (t, J=7.0 Hz, 3H, OCH.sub.2CH.sub.3).

Example 37

[0179] Ethyl (9-chloro-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, the compound was obtained as brown solid in 86% yield: mp 102.8-102.9 C.; .sup.1H-NMR (200 MHz, CDCl.sub.3): 8.47-7.99 (m, 3H, ArH), 7.64 (dt, J=1.5 and 7.5 Hz, 1H, ArH), 7.53 (dt, J=1.2 and 7.7 Hz, 1H, ArH), 7.34 (dd, J=2.3 and 8.7 Hz, 1H, ArH), 7.17 (d, J=8.7 Hz, 1H, ArH), 4.59 (s, 2H, NCH.sub.2), 3.96 (q, J=7.2 Hz, 2H, OCH.sub.2CH.sub.3), 1.00 (t, J=7.2 Hz, 3H, OCH.sub.2CH.sub.3).

Example 38

[0180] Ethyl [5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, the compound was obtained as pale brown solid in 80% yield: mp 101-103 C. .sup.1H-NMR (200 MHz, DMSO-d.sub.6): 8.60 (brs, 1H, ArH), 8.35 (d, J=8.0 Hz, 1H, ArH), 8.00-7.75 (m, 3H, ArH), 7.74-7.65 (m, 2H, ArH), 4.91 (s, 2H, NCH.sub.2), 3.92 (q, J=7.4 Hz, 2H, OCH.sub.2CH.sub.3), 0.92 (t, J=7.4 Hz, 3H, OCH.sub.2CH.sub.3).

Example 39

[0181] Ethyl [9-(methylthio)-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, the compound was obtained as yellowish solid in 73% yield: mp 103-105 C. .sup.1H-NMR (200 MHz, DMSO-d.sub.6): 8.02-7.91 (m, 3H, ArH), 7.75 (t, J=7.9 Hz, 1H, ArH), 7.61 (t, J=7.4 Hz, 1H, ArH), 7.45-7.35 (m, 1H, ArH), 7.26-7.23 (m, 1H, ArH), 4.66 (s, 2H, NCH.sub.2), 4.05 (q, J=6.9 Hz, 2H, OCH.sub.2CH.sub.3), 2.57 (s, 3H, SCH.sub.3), 1.07 (t, J=6.9 Hz, 3H, OCH.sub.2CH.sub.3).

Example 40

[0182] Ethyl (9-methoxy-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, the compound was obtained as brown solid in 85% yield: mp 101-104 C. .sup.1H-NMR (200 MHz, DMSO-d.sub.6): 8.26 (d, J=7.9 Hz, 1H, ArH), 7.88-7.74 (m, 2H, ArH), 7.70-7.62 (m, 2H, ArH), 7.49 (d, J=8.9 Hz, 1H, ArH), 7.12 (dd, J=2.7 and 8.9 Hz, 1H, ArH), 4.75 (s, 2H, NCH.sub.2), 3.94-3.77 (m, 5H, OCH.sub.3 and OCH.sub.2CH.sub.3), 0.90 (t, J=7.0 Hz, 3H, OCH.sub.2CH.sub.3).

Example 41

[0183] Ethyl (7-bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, the compound was obtained, after crystallization by EtOH, as pink solid in 50% yield: mp 169-171 C. .sup.1H-NMR (400 MHz, CDCl.sub.3) 7.96-7.90 (m, 3H, ArH), 7.75-7.67 (m, 2H, ArH), 7.58 (t, J=7.8, 1H, ArH), 7.30 (t, J=7.9 Hz, 1H, ArH), 4.73 (s, 2H, NCH.sub.2), 3.80 (q, J=7.1 Hz, 2H, OCH.sub.2CH.sub.3), 1.00 (t, J=7.1 Hz, 3H, OCH.sub.2CH.sub.3).

Example 42

[0184] Ethyl (8,10-dichloro-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, was obtained as pink solid in 90% yield: mp 172-173 C. .sup.1H-NMR (200 MHz, CDCl.sub.3) 8.49 (dd, J=1.3 and 7.9 Hz, 1H, ArH), 7.90 (dd, J=1.8 and 7.6 Hz, 1H, ArH), 7.70-7.55 (m, 2H, ArH), 7.10 (d, J=2.1 Hz, 1H, ArH), 4.51 (s, 2H, NCH.sub.2), 4.02 (q, J=7.2 Hz, 2H, OCH.sub.2CH.sub.3), 1.05 (t, J=7.2 Hz, 3H, OCH.sub.2CH.sub.3).

Example 43

[0185] Ethyl [3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, was obtained as pale brown solid in 85% yield: m.p. 175-177 C.; .sup.1H NMR (400 MHz, DMSO-d.sub.6): 1.10 (t, J=7.2 Hz, 3H, OCH.sub.2CH.sub.3), 4.10 (q, J=7.2 Hz, 2H, OCH.sub.2CH.sub.3), 4.75 (s, 1H, NCH.sub.2), 7.35 (d, J=8.5 Hz, 1H, H-7), 7.45 (dt, J=2.7 and 8.3 Hz, 1H, H-2), 7.60-7.70 (m, 2H, H-4 and H-8), 8.00 (dd, J=4.6 and 8.8 Hz, 1H, H-1), 8.20 (s, 1H, H-10).

Example 44

[0186] Ethyl [3-methoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetate: following the general procedure reported above and starting from the corresponding dibenzothiazine of formula 5a, the compound was obtained as pink solid in 86% yield: m.p. 190-192 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 1.03 (t, J=7.0 Hz, 3H, OCH.sub.2CH.sub.3), 3.95 (s, 3H, OCH.sub.3), 3.98 (q, J=7.4 Hz, 2H, OCH.sub.2CH.sub.3), 4.93 (s, 2H, NCH.sub.2), 7.42-7.45 (m, 2H, H-2 and H-4), 7.73 (d, J=8.6 Hz, 1H, H-7), 7.85 (d, J=8.4 Hz, 1H, H-8), 8.38 (d, J=8.4 Hz, 1H, H-1), 8.54 (s, 1H, H-10).

Example 45

[0187] N-[2-(9-bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)ethyl]cyclohexanamine (SM9). In a microwave reactor tube, a solution of the appropriate compound of formula 5a (0.6 g, 1.9 mmol), N-(2-chloroethyl)cyclohexanamine (0.31 g, 1.9 mmol), and DIPEA (0.66 mL, 3.8 mmol) in dry DMF (4 mL) was irradiated at 70 C. for 60 min. by setting the following experimental parameters: pressure 5 bar, cooling off, FHT on, solvent absorption very high. The residue was poured into ice-water acidified to pH 3 with 2N HCl and extracted with EtOAc (320 mL). The combined organic layers were washed with brine, dried, and evaporated to dryness to give a crude slurry mass that was purified by flash column chromatography eluting with CHCl.sub.3/MeOH (97:3) giving the target compound SM9 (0.65 g, 79%) as low melting pale brown solid: .sup.1H NMR (400 MHz, CDCl.sub.3): 8.13 (d, J=2.2 Hz, 1H, ArH), 7.99 (dd, J=1.1 and 7.7 Hz, 1H, H-4), 7.92 (d, J=7.2 Hz, 1H, ArH), 7.73 (dt, J=1.3 and 7.8 Hz, 1H, ArH), 7.64-7.58 (m, 2H, ArH), 7.40 (d, J=8.7 Hz, 1H, ArH), 4.00 (t, J=6.7 Hz, 2H, SO.sub.2NCH.sub.2), 2.85 (t, J=6.7 Hz, 2H, NCH.sub.2), 2.40-2.25 (m, 1H, Cy-CH), 1.75-1.50 (m, 4H, Cy-CH.sub.2), 1.25-1.00 (m, 4H, Cy-CH.sub.2), 1.00-0.80 (m, 2H, Cy-CH.sub.2). .sup.13C NMR (100 MHz, CDCl.sub.3): 137.58, 135.22, 133.05, 132.42, 131.16, 128.95, 128.45, 127.15, 125.68, 123.56, 122.51, 118.59, 56.17, 49.17, 44.52, 32.97, 25.87, 24.72. HRMS (ESI) calcd. for C.sub.20H.sub.23BrN.sub.2O.sub.2S[M.sup.++H].sup.+: 435.0739, found: 435.0735; LC-MS: ret. time 4.075.

Example 46

[0188] (R,S)-3-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-1-cyclohexylpyrrolidin-2-one (SM1l). Following the procedure above described for compound SM9 and using 3-bromo-1-cyclohexyl-2-pyrrolidinone.sup.37, the title compound was purified by flash column chromatography, eluting with cyclohexane/EtOAc (6:4), and subsequent trituration with petroleum ether/Et.sub.2O, to give racemic target compound SM1l as a white solid in 70% yield: mp 177-179 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.42 (d, J=2.1 Hz, 1H, ArH), 8.28 (d, J=7.8 Hz, 1H, ArH), 7.91 (d, J=7.7 Hz, 1H, ArH), 7.85 (t, J=8.6 Hz, 1H, ArH), 7.75-7.70 (m, 2H, ArH), 7.30 (d, J=8.6 Hz, 1H, H-7), 7.37 (d, J=8.6 Hz, 1H, ArH), 4.90 (t, J=9.4 Hz, 2-Pyrrolidone-CH), 3.75-3.55 (m, 1H, Cy-CH), 3.20-3.00 (m, 2H, 2-Pyrrolidone-CH), 2.10-2.00 (m, 1H, 2-Pyrrolidone-CH), 1.75-1.48 (m, 6H, Cy-CH.sub.2 and 2-Pyrrolidone-CH), 1.40-1.00 (m, 5H, Cy-CH.sub.2). .sup.13C NMR (100 MHz, DMSO-d.sub.6): 168.65, 136.83, 135.87, 133.56, 133.48, 131.05, 130.15, 129.38, 128.95, 127.40, 126.72, 122.36, 119.96, 62.56, 51.37, 25.45, 25.38, 25.33, 25.19, 22.83. HRMS (ESI) calcd for C.sub.22H.sub.23BrN.sub.2O.sub.3S: [M.sup.++H].sup.+: 475.0692, found: 475.03691; LC-MS: ret. time 6.015.

Example 47

[0189] Methyl 3-(9-bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)propanoate: To a solution the appropriate compound of formula 5a (0.300 g, 0.92 mmol) in dry THE (12 mL), commercial methyl 3-hydroxypropanoate (0.12 mL, 1.3 mmol) and PPh.sub.3 (0.33 g, 1.3 mmol), were added and the solution was sonicated at 25 C. for 7 min. DEAD (0.20 mL, 1.3 mmol) was then added drop-wise and the solution was sonicated for 18 h at 25 C. (approximately 70% of conversion followed by TLC). The mixture was concentrated under reduced pressure, poured into ice-water, basified with aqueous 10% NaOH to pH 10 in order to remove the residual starting material, and extracted with EtOAc (320 mL). The combined organic layers were washed brine, dried, and evaporated to dryness. The obtained brown oil was purified by column chromatography (petroleum ether/EtOAc 7:3) followed by trituration with Et.sub.2O to give the desired title compound of formula 6a (0.100 g, 30%) as a white solid: mp 101-103 C. .sup.1H NMR (200 MHz, CDCl.sub.3): 8.10 (d, J=2.3 Hz, 1H, ArH), 7.94-7.83 (m, 2H, ArH), 7.70 (dt, J=1.5 and 7.4 Hz, 2H, ArH), 7.60-7.50 (m, 2H, ArH), 7.28 (d, J=8.8 Hz, 1H, ArH), 4.10 (t, J=7.4 Hz, 2H, NCH.sub.2), 3.50 (s, 3H, CH.sub.3), 2.50 (t, J=7.4 Hz, 2H, CH.sub.2).

[0190] General procedure of direct amidation of compounds of formula 6a with cyclohexylamine to obtain target compounds of formula 8a (Scheme 1): Using the microwave oven a tube containing a mixture of appropriate dibenzothiazine ethyl acetate or the intermediate in example 44 of general formula 6a (1 equiv.) and cyclohexylamine (4 equiv.) was irradiated at 120 C. for 4 h by setting the following experimental parameters: pressure 5 bar, cooling off, FHT on, solvent absorption normal. The residue was poured into ice-water and acidified with 2 N HCl to pH 3. The obtained precipitate was filtered off and crystallized by EtOH to give the target compound of formula 8a.

Example 48

[0191] 2-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM3): following the general procedure above described the title compound was obtained as white solid in 62% yield: mp 211-213 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 8.20 (brs, 1H, ArH), 8.00 (d, J=7.8 Hz, 1H, ArH), 7.87 (d, J=7.8 Hz, 1H, ArH), 7.75 (t, J=7.5 Hz, 1H, ArH), 7.73 (t, J=7.4 Hz, 1H, ArH), 7.57 (d, J=7.4 Hz, 1H, ArH), 7.12 (d, J=8.7 Hz, 1H, H-7), 6.54 (d, J=7.0 Hz, 1H, NH), 4.42 (s, 2H, NCH.sub.2), 3.90-3.75 (m, 1H, Cy-CH), 1.95-1.75 (m, 2H, Cy-CH), 1.65-1.50 (m, 3H, Cy-CH), 1.45-1.25 (m, 2H, Cy-CH), 1.25-1.05 (m, 3H, Cy-CH). .sup.13C NMR (100 MHz, DMSO-d.sub.6): 166.29, 137.11, 134.09, 133.49, 133.12, 131.05, 129.18, 128.57, 125.91, 125.59, 122.56, 121.09, 118.62, 51.64, 48.45, 32.45, 25.35, 24.35. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.21BrN.sub.2O.sub.3S: 448.0535, found: 448.0456; LC-MS: ret. time 5.754.

Example 49

[0192] 2-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclopentylacetamide (SM4): following the general procedure above described the title compound was obtained, after crystallization by EtOH, as white solid in 43% yield: mp 192-194 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 8.19 (d, J=2.1 Hz, 1H, ArH), 8.04 (d, J=7.9 Hz, 1H, ArH), 7.99 (d, J=7.9 Hz, 1H, ArH), 7.80 (dt, J=1.2 and 7.6 Hz, 1H, ArH), 7.69-7.61 (m, 2H, ArH), 7.15 (d, J=8.7 Hz, 1H, ArH), 6.62 (d, J=7.5 Hz, 1H, NH), 4.46 (s, 2H, NCH.sub.2), 4.31-4.24 (m, 1H, cyclopentyl-CH), 2.00-1.92 (m, 2H, cyclopentyl-CH.sub.2), 1.70-1.55 (m, 4H, cyclopentyl-CH.sub.2), 1.45-1.30 (m, 2H, cyclopentyl-CH.sub.2). .sup.13C NMR (100 MHz, CDCl.sub.3): 166.76, 137.03, 134.04, 133.49, 133.14, 131.00, 129.20, 128.57, 125.90, 125.53, 122.53, 121.04, 118.61, 51.60, 51.49, 32.80, 23.45. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.19H.sub.19BrN.sub.2O.sub.3S: 435.0379, found: 435.03733; LC-MS: ret. time 5.434.

Example 50

[0193] 2-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cycloheptylacetamide (SM5): following the general procedure above described the title compound was obtained, after crystallization by EtOH, as white solid in 51% yield: mp 208-210 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 8.18 (d, J=1.8 Hz, 1H, ArH), 8.03 (d, J=7.4 Hz, 1H, ArH), 7.98 (d, J=7.9 Hz, 1H, ArH), 7.80 (t, J=7.6 Hz, 1H, H-2), 7.70-7.60 (m, 2H, ArH), 7.15 (d, J=8.7 Hz, 1H, ArH), 6.60 (d, J=7.5 Hz, 1H, NH), 4.45 (s, 2H, NCH.sub.2), 4.20-3.95 (m, 1H, cycloheptyl-CH), 1.90-177 (m, 2H, cycloheptyl-CH.sub.2), 1.70-1.30 (m, 10H, cycloheptyl-CH.sub.2). .sup.13C NMR (100 MHz, CDCl.sub.3): 166.01, 137.08, 134.08, 133.47, 133.13, 131.04, 129.18, 128.57, 125.92, 125.55, 122.55, 121.04, 118.60, 51.60, 50.63, 34.59, 27.84, 23.72. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.21H.sub.23BrN.sub.2O.sub.3S: 463.0689, found: 463.0688; LC-MS: ret. time 6.018.

Example 51

[0194] 3-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylpropanamide (SM10). following the general procedure above described the title compound was obtained, after purification by flash column chromatography (cyclohexane/EtOAc 7:3), as white solid in 34% yield: mp 114-116 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 8.13 (brs, 1H, ArH), 8.00 (d, J=7.6 Hz, 1H, ArH), 7.90 (d, J=7.7 Hz, 1H, ArH), 7.75 (t, J=7.7 Hz, 1H, ArH), 7.65-7.60 (m, 2H, ArH), 7.42 (d, J=8.7 Hz, 1H, ArH), 5.55 (d, J=6.4 Hz, 1H, NH), 4.15 (t, J=6.6 Hz, 2H, NCH.sub.2), 3.75-3.60 (m, 1H, Cy-CH), 2.60 (t, J=6.6 Hz, 2H, CH.sub.2), 1.85-1.53 (m, 5H, Cy-CH.sub.2), 1.50-1.10 (m, 5H, Cy-CH.sub.2). .sup.13C NMR (100 MHz, CDCl.sub.3): 168.33, 137.37, 134.19, 132.91, 132.21, 130.81, 128.46, 127.79, 126.07, 125.26, 123.13, 122.13, 118.23, 47.96, 45.98, 36.49, 32.36, 24.90, 24.18. HRMS (ESI) calcd for C.sub.21H.sub.23BrN.sub.2O.sub.3S [M.sup.++H].sup.+: 463.0689, found: 463.0693; LC-MS: ret. time 4.772

Example 52

[0195] 2-(9-chloro-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM254): following the general procedure above described the title compound was obtained, after crystallization by EtOH, as white solid in 60% yield: mp 218-220 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 8.02-7.95 (m, 2H, ArH), 7.92 (d, J=8.1 Hz, 1H, ArH), 7.75 (dt, J=1.2 and 7.7 Hz, 1H, ArH), 7.63 (dt, J=0.8 and 8.0 Hz, 1H, ArH), 7.43 (dd, J=2.2 and 8.7 Hz, 1H, ArH), 7.18 (d, J=8.7 Hz, 1H, H-7), 6.53 (d, J=7.0 Hz, 1H, NH), 4.42 (s, 2H, NCH.sub.2), 3.90-3.75 (m, 1H, Cy-CH), 1.90-1.75 (m, 2H, Cy-CH), 1.65-1.50 (m, 4H, Cy-CH), 1.40-1.25 (m, 2H, Cy-CH), 1.25-1.05 (m, 2H, Cy-CH). .sup.13C NMR (100 MHz, CDCl.sub.3): 166.29, 136.69, 134.16, 133.08, 131.17, 131.11, 130.58, 129.16, 125.88, 125.61, 125.32, 122.58, 120.97, 51.75, 48.45, 32.45, 25.34, 24.32; HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.21ClN.sub.2O.sub.3S: 405.1039, found: 404.1032. LC-MS: ret. time 6.492 min.

Example 53

[0196] N-cyclohexyl-2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM231): following the general procedure above described the title compound was obtained, after purification by flash column chromatography (cyclohexane/EtOAc 7:3), as white solid in 70% yield: mp 225-226 C. .sup.1H-NMR (200 MHz, CDCl.sub.3): 8.29 (brs, 1H, ArH), 8.03 (d, J=7.5 Hz, 1H, ArH), 7.81 (d, J=7.8 Hz, 1H, ArH), 7.75-7.65 (m, 2H, ArH), 7.35 (d, J=8.4 Hz, 1H, ArH), 6.57 (brs, 1H, NH), 4.52 (s, 2H, NCH.sub.2), 3.85-3.75 (m, 1H, Cy-CH), 1.85-1.75 (m, 2H, Cy-CH), 1.65-1.48 (m, 3H, Cy-CH), 1.40-1.25 (m, 2H, Cy-CH), 1.20-1.10 (m, 3H, Cy-CH). .sup.13C NMR (100 MHz, CDCl.sub.3): 166.04, 140.60, 134.01, 133.29, 131.16, 129.36, 127.33 (q, J.sub.C-F=33.1 Hz, C-9), 127.32 (d, J.sub.C-F=3.5 Hz, C-10), 126.02, 123.86, 123.63 (q, J.sub.C-F=270.7 Hz, CF.sub.3), 122.96 (d, J.sub.C-F=3.8 Hz, C-8), 119.49, 51.25, 48.55, 32.43, 25.32, 24.33. HRMS (ESI) m/z [M+Na].sup.+ calcd. for C.sub.21H.sub.21F.sub.3N.sub.2O.sub.3S: 461.1118, found: 461.1124. LC-MS: ret. time 4.688 min.

Example 54

[0197] N-cyclohexyl-2-[9-(methylthio)-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM340): following the general procedure above described the title compound was obtained, after crystallization by EtOH, as white solid in 63% yield: mp 178-180 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.03-7.98 (m, 2H, ArH), 7.92 (d, J=1.6 Hz, 1H, ArH), 7.78 (t, J=7.6 Hz, 1H, ArH), 7.64 (t, J=7.4 Hz, 1H, ArH), 7.39 (dd, J=1.9 and 8.6 Hz, 1H, ArH), 7.20 (d, J=8.6 Hz, 1H, ArH), 6.60 (d, J=7.5 Hz, 1H, NH), 4.44 (s, 2H, NCH.sub.2), 3.90-3.75 (m, 1H, Cy-CH), 2.58 (s, 3H, SCH.sub.3), 1.90-1.80 (m, 2H, Cy-CH), 1.75-1.50 (m, 3H, Cy-CH), 1.40-1.25 (m, 2H, Cy-CH), 1.20-1.10 (m, 3H, Cy-CH). .sup.13C-NMR (100 MHz, CDCl.sub.3): 166.60, 135.92, 135.61, 134.20, 132.99, 131.79, 129.14, 128.79, 125.81, 124.44, 124.07, 122.59, 120.25, 51.84, 48.39, 32.46, 25.35, 24.35, 16.44. HRMS (ESI) m/z [M+H].sup.+ calcd for C.sub.21H.sub.24N.sub.2O.sub.3S.sub.2: 417.1309, found: 417.1305; LC-MS: ret. time 5.403 min.

Example 55

[0198] N-Cyclohexyl-2-(9-methoxy-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetamide (SM225): following the general procedure above described the title compound was obtained, after purification by flash column chromatography (cyclohexane/EtOAc 7:3), as white solid in 45% yield: mp 216-217 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 7.99-7.93 (m, 2H, ArH), 7.74 (t, J=7.6 Hz, 1H, ArH), 7.59 (t, J=7.6 Hz, 1H, ArH), 7.49 (d, J=2.6 Hz, 1H, ArH), 7.20 (d, J=8.9 Hz, 1H, ArH), 7.02 (dd, J=2.7 and 8.9 Hz, 1H, ArH), 6.59 (d, J=7.8 Hz, 1H, NH), 4.32 (s, 2H, NCH.sub.2), 3.88-3.75 (m, 4H, OCH.sub.3, and Cy-CH), 1.85-1.75 (m, 2H, Cy-CH), 1.65-1.50 (m, 3H, Cy-CH), 1.35-1.25 (m, 2H, Cy-CH), 1.20-1.10 (m, 3H, Cy-CH). .sup.13C-NMR (100 MHz, CDCl.sub.3): 166.82, 157.36, 134.29, 132.96, 132.22, 131.86, 128.76, 125.87, 125.50, 122.84, 121.68, 116.50, 110.77, 55.78, 52.75, 48.27, 32.52, 25.39, 24.43. HRMS (ESI) m/z [M+H].sup.+ calcd for C.sub.21H.sub.24N.sub.2O.sub.4S: 401.1539, found: 401.1533; LC-MS: ret. time 5.544 min.

Example 56

[0199] 2-(7-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM227): following the general procedure above described the title compound was obtained, after purification by flash column chromatography (cyclohexane/EtOAc 6:4), as white solid in 40% yield:mp 159-160 C. .sup.1H-NMR (200 MHz, DMSO-d.sub.6) 8.15 (d, 2H, H-4 and H-8), 7.70-7.85 (m, 4H, H-1, H-9, H-10 and NH), 7.55-7.70 (t, J=7.4 Hz, 1H, H-2), 7.40 (t, J=7.9 Hz, 1H, H-3), 4.40 (brs, 2H, NCH.sub.2), 3.00-3.10 (m, 1H, cyclohexyl CH), 0.60-1.60 (m, 10H, cyclohexyl CH.sub.2). .sup.13C-NMR (100 MHz, CDCl.sub.3): 165.51, 139.33, 134.86, 133.55, 133.17, 132.58, 130.40, 129.51, 129.50, 126.35, 125.40, 125.09, 121.45, 54.69, 48.36, 32.70, 25.52, 25.40. HRMS (ESI) m/z [M+H].sup.+ calcd for C.sub.20H.sub.21BrN.sub.2O.sub.3S: 448.0539, found: 448.0267; LC-MS: ret. time 4.10 min.

Example 57

[0200] 2-(8-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM228) and 2-(10-bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM229): following the general procedure above described a mixture of the two regioisomers of formula 6a was reacted with cyclohexylamine obtaining the two regioisomers of formula 8a that were separated by flash column chromatography (CH.sub.2Cl.sub.2/acetone 98:2) and each compound was further purified by crystallization with EtOH to afford target compounds SM228 (R.sub.f>by TLC) and SM229 (R.sub.f<by TLC).

[0201] SM228: 8% yield: mp 184-185 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.10-7.80 (m, 3H, ArH), 7.82 (t, J=7.4 Hz, 1H, ArH), 7.65 (t, J=7.6 Hz, 1H, ArH), 7.52 (dd, J=1.5 and 8.5 1H, ArH), 7.40 (brs, 1H, ArH), 6.55 (d, J=8.0 Hz, 1H, NH), 4.50 (s, 2H, NCH.sub.2), 4.00-3.75 (m, 1H, Cy-CH), 2.00-1.80 (m, 2H, Cy-CH.sub.2), 1.75-1.50 (m, 2H, Cy-CH.sub.2), 1.45-1.00 (m, 6H, Cy-CH.sub.2). .sup.13C NMR (100 MHz, DMSO-d.sub.6): 165.60, 140.02, 134.99, 133.22, 131.50, 129.45, 128.16, 127.94, 126.66, 123.86, 123.82, 123.30, 121.76, 50.06, 48.12, 32.67, 25.53, 24.76. HRMS (ESI) m/z [M+Na].sup.+ calcd for C.sub.20H.sub.21BrN.sub.2O.sub.3S: 471.0354, found: 471.041; LC-MS: ret. time 12.592 min.

[0202] SM229: 21% yield: mp 211-212 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.62 (d, J=8.3 Hz, 1H, ArH), 8.00 (dd, J=1.4 and 7.8 Hz, 1H, ArH), 7.75-7.65 (m, 4H, ArH), 7.28-7.24 (m, 2H, ArH), 6.50 (d, J=8.1 Hz, 1H, NH), 4.40 (s, 2H, NCH.sub.2), 3.80-3.70 (m, 1H, Cy-CH), 1.90-1.80 (m, 2H, Cy-CH.sub.2), 1.75-1.50 (m, 2H, Cy-CH.sub.2), 1.45-1.00 (m, 6H, Cy-CH.sub.2). NMR COSY spectrum showed two relevant NOE cross-peaks: H-9 ( 7.70, dd).fwdarw.H-8 ( 7.32, t), H-9.fwdarw.H-7 ( 7.28, dd). NMR NOESY spectrum showed one relevant NOE cross-peak: H-8.fwdarw.NCH.sub.2. .sup.13C NMR (100 MHz, DMSO-d.sub.6): 165.49, 140.92, 134.85, 131.81, 131.48, 131.19, 131.13, 130.37, 129.41, 125.44, 121.64, 121.38, 120.59, 50.77, 48.11, 32.66, 25.52, 24.76. HRMS (ESI) m/z [M+Na].sup.+ calcd for C.sub.20H.sub.21BrN.sub.2O.sub.3S: 471.0354, found: 471.0407; LC-MS: ret. time 12.893 min.

Example 58

[0203] 2-(8-chloro-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM586) and 2-(10-chloro-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM585): following the general procedure above described a mixture of the two appropriate regioisomers of formula 6a was reacted with cyclohexylamine obtaining the two regioisomers of formula 8a that were separated by flash column chromatography (CH.sub.2Cl.sub.2/acetone 98:2) and each compound was further purified by crystallization with EtOH to afford target compounds SM586 (R.sub.f>by TLC) and SM585 (R.sub.f<by TLC).

[0204] SM586: 18% yield: mp 193-195 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.02-7.90 (m, 3H, ArH), 7.74 (dt, J=1.2 and 7.7 Hz, 1H, ArH), 7.60 (dt, J=0.7 and 8.0 Hz, 1H, ArH), 7.33 (dd, J=2.0 and 8.2 Hz, 1H, ArH), 7.28 (d, J=2.0 Hz, 1H, ArH), 6.50 (d, J=7.5 Hz, 1H, NH), 4.49 (s, 2H, NCH.sub.2), 3.90-3.75 (m, 1H, Cy-CH), 1.90-1.80 (m, 2H, Cy-CH.sub.2), 1.75-1.50 (m, 4H, Cy-CH.sub.2), 1.45-1.35 (m, 2H, Cy-CH.sub.2), 1.20-1.05 (m, 2H, Cy-CH.sub.2); .sup.13C-NMR (100 MHz, CDCl.sub.3): 166.05, 139.07, 136.51, 133.87, 133.07, 131.56, 128.74, 126.80, 125.71, 125.68, 122.52, 122.41, 119.71, 51.57, 48.41, 32.41, 25.36, 24.30; HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.21ClN.sub.2O.sub.3S: 405.1039, found:405.1037; LC-MS: ret. time 5.628 min.

[0205] SM585: 15% yield: mp 200-202 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.60 (d, J=8.0 Hz, 1H, ArH), 7.95 (dd, J=1.2 and 8.5 Hz, 1H, ArH), 7.70 (dt, J=1.3 and 8.5 Hz, 1H, ArH), 7.59 (dd, J=1.2 and 8.0 Hz, 1H, ArH), 7.43 (dd, J=1.1 and 8.1 Hz, 1H, ArH), 7.34 (t, J=8.1 Hz, 1H, ArH), 7.20 (dd, J=1.1 and 8.1 Hz, 1H, ArH), 6.35 (d, J=7.0 Hz, 1H, NH), 4.48 (s, 2H, NCH.sub.2), 3.90-3.75 (m, 1H, Cy-CH), 1.90-1.80 (m, 2H, Cy-CH.sub.2), 1.75-1.50 (m, 4H, Cy-CH.sub.2), 1.45-1.35 (m, 2H, Cy-CH.sub.2), 1.20-1.05 (m, 2H, Cy-CH.sub.2); .sup.13C-NMR (100 MHz, CDCl.sub.3): 166.25, 139.99, 135.69, 132.59, 131.57, 130.35, 130.16, 130.02, 128.78, 128.70, 123.48, 122.29, 118.69, 52.15, 48.38, 32.45, 25.34, 24.33; HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.21ClN.sub.2O.sub.3S: 405.1039, found: 405.1037; LC-MS: ret. time 5.631 min.

Example 59

[0206] N-cyclohexyl-2-[5,5-dioxido-8-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM338) and N-cyclohexyl-2-[5,5-dioxido-10-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM339): following the general procedure above described a mixture of the two appropriate regioisomers of formula 6a was reacted with cyclohexylamine obtaining the two regioisomers of formula 8a that were separated by flash column chromatography(CH.sub.2Cl.sub.2/acetone 99:1) and each compound was further purified by crystallization with EtOH to afford target compounds SM338 (R.sub.f>by TLC) and SM339 (R.sub.f<by TLC).

[0207] SM338: 40% yield: mp 230-232 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.20-8.10 (d, J=8.2 Hz, 1H, ArH), 8.05-7.98 (m, 2H, ArH), 7.78 (dt, J=1.5 and 7.5 Hz, 1H, ArH), 7.78 (dt, J=1.5 and 7.5 Hz, 1H, ArH), 7.69 (dt, J=1.3 and 7.7 Hz, 1H, ArH), 7.65 (d, J=8.0 Hz, 1H, ArH), 7.50 (brs, 1H, ArH), 6.50 (d, J=6.9 Hz, 1H, NH), 4.48 (s, 2H, NCH.sub.2), 3.90-3.75 (m, 1H, Cy-CH), 1.90-1.80 (m, 2H, Cy-CH.sub.2), 1.75-1.50 (m, 4H, Cy-CH.sub.2), 1.45-1.35 (m, 2H, Cy-CH.sub.2), 1.20-1.05 (m, 2H, Cy-CH.sub.2); .sup.13C-NMR (100 MHz, CDCl.sub.3): 165.86, 138.57, 134.66, 133.16, 132.50 (q, J.sub.C-F=33.1 Hz, C-8), 131.11, 129.58, 127.08, 126.42, 126.27, 123.79 (q, J.sub.C-F=271.0 Hz, CF.sub.3), 122.59, 121.89 (q, J.sub.C-F=5 Hz, C-9), 116.83 (q, J.sub.C-F=6 Hz, C-7), 51.71, 48.44, 32.40, 25.33, 24.33; HRMS (ESI) m/z [M+H].sup.+ calcd for C.sub.21H.sub.21F.sub.3N.sub.2O.sub.3S: 439.1303, found: 439.1296; LC-MS: ret. time 6.892 min.

[0208] SM339: 26% yield: mp 211-212 C.; .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.03-7.95 (m, 2H, ArH), 7.82-7.58 (m, 4H, ArH), 7.51 (d, J=8.3 Hz, 1H, ArH), 6.35 (d, J=8.0 Hz, 1H, NH), 4.40 (s, 2H, NCH.sub.2), 4.00-3.75 (m, 1H, Cy-CH), 1.90-1.80 (m, 2H, Cy-CH.sub.2), 1.75-1.50 (m, 4H, Cy-CH.sub.2), 1.45-1.05 (m, 4H, Cy-CH.sub.2); .sup.13C-NMR (100 MHz, CDCl.sub.3): 168.08, 140.01 (brs, C-6a), 139.80, 134.90, 134.32, 132.30, 130.56, 127.7 (d, J.sub.C-F=2.0 Hz, C-8), 124.57, 122.30 (q, J.sub.C-F=29.0 Hz, C-10), 119.60 (q, J.sub.C-F=270.1 Hz, CF.sub.3), 117.80 (q, J.sub.C-F=3.1 Hz, C-9), 115.85 (q, J.sub.C-F 2.0 Hz, C-10a), 115.09, 52.02, 49.50, 32.40, 26.28, 24.12; HRMS (ESI) m/z [M+H].sup.+ calcd for C.sub.21H.sub.21F.sub.3N.sub.2O.sub.3S: 439.1303, found: 439.1298; LC-MS: ret. time 6.598 min.

Example 60

[0209] 2-(8-chloro-9-fluoro-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM336) and 2-(10-chloro-9-fluoro-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM337): following the general procedure above described a mixture of the two appropriate regioisomers of formula 6a was reacted with cyclohexylamine obtaining the two regioisomers of formula 8a that were separated by flash column chromatography (cyclohexane/EtOAc 7:3) followed by crystallization with EtOH to afford target compounds SM336 (R.sub.f>by TLC) and SM337 (R.sub.f<by TLC).

[0210] SM336: 21% yield: mp 211-213 C. .sup.1H-NMR (400 MHz, DMSO-d.sub.6): 7.96 (dd, J=1.5 and 7.0 Hz, 1H, ArH), 7.8 (d, J=8.2 Hz, 1H, ArH), 7.78-7.70 (m, 2H, ArH), 7.61 (dt, J=1.4 and 7.7 Hz, 1H, ArH), 7.33 (d, J=6.4 Hz, 1H, ArH), 6.4 (d, J=9.0 Hz, 1H, ArH), 4.35 (s, 2H, NCH.sub.2), 3.80-3.70 (m, 1H, Cy-CH), 1.85-1.75 (m, 2H, Cy-CH.sub.2), 1.75-1.45 (m, 2H, Cy-CH.sub.2), 1.45-1.00 (m, 6H, Cy-CH.sub.2). .sup.13C NMR (100 MHz, DMSO-d.sub.6): 165.59, 154.86 (d, J.sub.C-F=243.0 Hz, C-9), 136.05 (d, J.sub.C-F=2.6 Hz, C-6a), 135.17, 133.19, 130.80, 130.05, 127.16, 125.69 (d, J.sub.C-F=8.0 Hz, C-10a), 123.97, 121.84, 121.29 (d, J.sub.C-F=20.0 Hz, C-8), 113.96 (d, J.sub.C-F=24.0 Hz, C-10), 50.97, 48.12, 32.62, 25.51, 24.73. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.2OClFN.sub.2O.sub.3S: 423.0946, found: 423.0938; LC-MS: ret. time 6.560 min.

[0211] SM337: 53% yield: mp 216-217 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.51 (d, J=8.2 Hz, 1H, ArH), 8.00 (d, J=7.7 Hz, 1H, ArH), 7.73 (dt, J=1.2 and 7.5 Hz, 1H, ArH), 7.64 (t, J=7.5 Hz, 1H, ArH), 7.35-7.20 (m, 2H, ArH), 6.25 (d, J=7.1 Hz, 1H, NH), 4.25 (s, 2H, NCH.sub.2), 3.80-3.70 (m, 1H, Cy-CH), 1.90-1.80 (m, 2H, Cy-CH.sub.2), 1.75-1.50 (m, 4H, Cy-CH.sub.2), 1.40-1.00 (m, 4H, Cy-CH.sub.2). .sup.13C NMR (100 MHz, CDCl.sub.3): 166.08, 156.77 (d, J.sub.C-F=246.1 Hz, C-9), 135.85 (brs, C-6a), 135.81, 131.72, 129.99, 129.81 (d, J.sub.C-F=2.8 Hz, C-10a), 129.39, 125.44, 122.69, 120.41 (J.sub.C-F=8.1 Hz, C-7), 119.5 (J.sub.C-F=20.1 Hz, C-10), 117.43 (J.sub.C-F=24.0 Hz, C-8), 52.73, 48.45, 32.53, 25.33, 24.39; HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.2OClFN.sub.2O.sub.3S: 423.0946, found: 423.0938; LC-MS: ret. time 6.520 min.

Example 61

[0212] N-cyclohexyl-2-(8,10-dichloro-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetamide (SM587): following the general procedure above described the title compound was obtained, after crystallization by EtOH, as white solid in 50% yield: mp 212.0-213.0 C.; H-NMR (200 MHz, DMSO-d.sub.6) 8.50 (d, J=8.0 Hz, 1H, ArH), 7.97 (dd, J=1.3 and 7.8, Hz, 1H, ArH), 7.71 (dt, J=1.4 and 8.0 Hz, 1H, ArH), 7.61 (dt, J=0.9 and 7.6, Hz, 1H, ArH), 7.45 (d, J=2.0 Hz, 1H, ArH), 7.22 (d, J=2.0 Hz, 1H, ArH), 6.28 (d, J=7.6 Hz, 1H, NH), 4.31 (s, 2H, NCH.sub.2), 3.80-3.70 (m, 1H, Cy-CH), 1.90-1.80 (m, 2H, Cy-CH.sub.2), 1.75-1.50 (m, 4H, Cy-CH.sub.2), 1.40-1.00 (m, 4H, Cy-CH.sub.2); .sup.13C NMR (100 MHz, CDCl.sub.3): 165.74, 140.50, 135.53, 135.44, 133.58, 131.78, 129.81, 129.75, 129.03, 128.46, 122.36, 122.06, 119.02, 52.00, 48.47, 32.46, 25.32, 24.37; HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.20Cl.sub.2N.sub.2O.sub.3S: 439.0649, found: 439.0646; LC-MS: ret. time 1.920 min.

Example 62

[0213] 2-(5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexylacetamide (SM7): to a suspension of LiAlH.sub.4 (0.021 g, 0.55 mmol) in dry THE (1 mL) cooled to 0 C., a solution of SM3 (0.100 g, 0.22 mmol) in dry THE (4 mL) was added drop-wise under N.sub.2 and then the mixture was stirred at 50 C. for 2 h. After cooling and quenching with EtOAc followed MeOH, the mixture was then poured into ice-water and extracted with EtOAc (320 mL). The combined organic layers were washed with brine, dried, and evaporated to dryness. The crude colorless oil obtained was purified by flash column chromatography, eluting with cyclohexane/EtOAc (7:3), to give SM7 (0.040 g, 49%) as a white solid: mp 176-178 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 8.25-8.00 (m, 3H, ArH), 7.77 (dt, J=1.2 and 8.4 Hz, 1H, ArH), 7.62 (t, J=7.7 Hz, 1H, ArH), 7.51 (dt, J=1.3 and 8.6 Hz, 1H, ArH), 7.39 (dt, J=1.0 and 8.4 Hz, 1H, ArH), 7.25 (dd, J=1.8 and 7.2 Hz, 1H, ArH), 6.60 (brs, 1H, NH), 4.48 (s, 2H, NCH.sub.2), 3.91-3.83 (m, 1H, Cy-CH), 1.90-1.80 (m, 2H, Cy-CH.sub.2), 1.60-1.50 (m, 3H, Cy-CH), 1.40-1.25 (m, 2H, Cy-CH.sub.2), 1.20-1.00 (m, 3H, Cy-CH). .sup.13C NMR (100 MHz, CDCl.sub.3): 166.18, 137.66, 133.57, 132.43, 131.81, 130.31, 127.98, 125.31, 125.21, 124.88, 123.36, 121.96, 118.99, 51.19, 47.85, 31.92, 24.87, 23.81. HRMS (ESI) calcd for C.sub.20H.sub.22N.sub.2O.sub.3S [M.sup.++H].sup.+: 371.1429, found: 371.1397. LC-MS: ret. time 5.212.

Example 63

[0214] N-Cyclohexyl-2-(9-hydroxy-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6yl)acetamide (SM226): to a solution of target compound SM225 (0.22 g. 0.55 mmol) in dry CH.sub.2Cl.sub.2 (12 mL) and under N.sub.2 flux, 1M BBr.sub.3 in CH.sub.2Cl.sub.2 (2.75 g, 2.75 mmol) was added dropwise at 60 C. and then the solution was stirred at 30 C. for 12 h. After quenching of the excess of BBr.sub.3 with MeOH, H.sub.2O, and saturated solution of NaHCO.sub.3, the mixture was acidified with 2N HCl to pH and extracted with CH.sub.2Cl.sub.2 (330 mL). The combined organic layers were washed with brine, dried, and evaporated to dryness and the residue which was purified by flash column chromatography (CHCl.sub.3/MeOH 95:5), to give compound SM226, as white solid in 88% yield: mp 216-217 C. .sup.1H-NMR (400 MHz, DMSO-d.sub.6): 9.77 (s, 1H, OH), 8.15 (d, J=8.9 Hz, 1H, ArH), 7.90-7.74 (m, 3H, ArH and NH), 7.62 (t, J=7.6 Hz, 1H, ArH), 7.45 (d, J=2.5 Hz, 1H, ArH), 7.25 (d, J=8.8 Hz, 1H, ArH), 6.85 (dd, J=2.6 and 8.7 Hz, 1H, ArH), 4.30 (s, 2H, NCH.sub.2), 3.40-3.30 (m, 1H, Cy-CH), 1.75-1.40 (m, 5H, Cy-CH.sub.2), 1.30-0.90 (m, 5H, Cy-CH.sub.2). .sup.13C-NMR (100 MHz, DMSO-d.sub.6): 166.19, 154.95, 143.08, 135.01, 133.28, 132.00, 129.29, 126.41, 126.31, 123.94, 121.99, 118.10, 111.45, 51.74, 48.13, 32.38, 25.31, 24.59. HRMS (ESI) m/z [M+H].sup.+ calcd for C.sub.20H.sub.22N.sub.2O.sub.4S: 387.1380, found: 387.1372; LC-MS: ret. time 4.691 min.

Example 64

[0215] N-Cyclohexyl-2-[9-[2-(dimethylamino)ethoxy]-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM230): to a solution of target compound SM226 (0.18 g. 0.47 mmol) in dry DMF (7 mL), Cs.sub.2CO.sub.3 (0.23 g. 0.70 mmol) and commercial 1-chloro-N,N-dimethylethanamine hydrochloride (0.07 g. 0.47 mmol) were added and the mixture was maintained under magnetic stirring at 85 C. for 2 h. The mixture was poured into ice-water, extracted with EtOAc (320 mL) and the combined organic layers were washed with brine, dried and evaporated to dryness to give an oil which was purified by flash column chromatography (CHCl.sub.3/MeOH 9:1), to afford SM230 as low melting solid in 57% yield: mp 66-67 C. .sup.1H-NMR (200 MHz, DMSO-d.sub.6): 8.23 (d, J=8.1 Hz, 1H, ArH), 7.90-7.65 (m, 3H, ArH and NH), 7.60-7.55 (m, 2H, ArH), 7.28 (d, J=8.9 Hz, 1H, ArH), 7.10 (dd, J=2.5 and 9.0 Hz, 1H, ArH), 4.40 (s, 2H, SO.sub.2NCH.sub.2), 4.20 (t, J=5.3 Hz, 2H, OCH.sub.2), 3.90-3.80 (m, 1H, Cy-CH), 2.80 (t, J=5.3 Hz, 2H, NCH.sub.2), 2.40 (s, 6H, NCH.sub.3), 1.75-1.40 (m, 5H, Cy-CH.sub.2), 1.30-0.90 (m, 5H, Cy-CH.sub.2). .sup.13C-NMR (100 MHz, DMSO-d.sub.6): 165.84, 156.34, 135.42, 132.86, 132.29, 132.26, 129.15, 126.89, 126.26, 123.65, 121.87, 117.63, 110.75, 66.68, 51.40, 48.04, 45.99, 32.66, 25.53, 24.77. HRMS (ESI) m/z [M+H].sup.+ calcd for C.sub.24H.sub.31N.sub.3O.sub.4S: 458.2200, found: 458.2200; LC-MS: ret. time 6.360 min.

[0216] Experimental procedure for making compounds of formula 7a in Scheme 1 are described below.

Example 65

[0217] 2-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetic acid of formula 7a: A stirred mixture of ethyl 2-(9-bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetate of formula 6a (Example 36; 0.600 g, 1.5 mmol) in aqueous 10% NaOH (7 mL) and EtOH (7 mL) was refluxed for 30 min, then cooled, concentrated under reduced pressure, poured into ice-water and acidified with 2N HCl to pH 2. The formed precipitate was filtered off to give the compound (0.540 g, 96%) as a white solid that was used as is in the next reaction step: mp 207-209 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.40 (d, J=2.2 Hz, 1H, ArH), 8.31 (d, J=8.0 Hz, 1H, ArH), 7.91 (dd, J=1.1 and 7.7 Hz, 1H, ArH), 7.84 (dt, J=1.3 and 7.7 Hz, 1H, ArH), 7.75-7.69 (m, 2H, ArH), 7.45 (d, J=8.7 Hz, 1H, H-7), 4.80 (s, 2H, NCH.sub.2).

Example 66

[0218] 3-Fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetic acid of formula 7a: to a solution of ethyl [3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetate of formula 6a (Example 43; 1.25 g, 3.09 mmol) in dioxane (25 mL), a solution of 1N LiOH monohydrate (2.47 mL) was added. The reaction mixture was stirred at room temperature for 10 min. and then poured into ice-water and acidified with 2N HCl (pH=2). The precipitate formed was filtered and dried to give the desired compound as white solid (1.16 g, 96%). .sup.1H NMR (400 MHz, CDCl.sub.3): 4.70 (s, 1H, NCH.sub.2), 7.35 (d, J=8.5 Hz, 1H, H-7), 7.40-7.50 (m, 1H, H-2), 7.60-7.65 (m, 1H, H-4), 7.70 (d, J=8.5 Hz, 1H, H-8), 8.00 (dd, J=4.5 and 8.8 Hz, 1H, H-1), 8.20 (s, 1H, H-10).

Example 67

[0219] 2-(9-bromo-5,5-dioxo-6H-dibenzo[c,e][1,2]thiazin-6 (5H)-yl)-N-phenylacetamide (SM6). A mixture of 2-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetic acid of general formula 7a (Example 65) (0.530 g, 1.44 mmol) and SOCl.sub.2 (2 mL) was refluxed under magnetic stirring for 1 h, then the excess of SOCl.sub.2 was removed by distillation and the residue was washed 3 times with dry toluene. The obtained acyl chloride was solubilized in dry DMF (7 mL) and added drop-wise, under N.sub.2 atmosphere, to a stirred solution of aniline (0.264 mL, 2.88 mmol) and Et.sub.3N (0.401 mL, 2.88 mmol) in dry DMF (3 mL) at room temperature. The mixture was left under magnetic stirring overnight then poured into ice-water and acidified with 2N HCl to pH 3. The precipitate was filtered and purified by flash column chromatography, eluting with CHCl.sub.3, to give target compound SM6 (0.150 g, 25%) as a white solid: mp 128-130 C. .sup.1H NMR (400 MHz, CDCl.sub.3): (8.37 (bs, 1H, NH), 8.20 (d, J=2.1 Hz, 1H, ArH), 8.10 (d, J=7.7 Hz, 1H, ArH), 8.00 (d, J=7.7 Hz, 1H, ArH), 7.80 (t, J=7.7 Hz, 1H, ArH), 7.70 (t, J=7.7 Hz, 1H, ArH), 7.60 (dd, J=2.2 and 7.8 Hz, 1H, ArH), 7.55-7.48 (m, 2H, ArH), 7.35-7.30 (m, 2H, ArH), 7.20 (d, J=7.8 Hz, 1H, ArH), 7.10 (t, J=7.4 Hz, 1H, ArH), 4.52 (s, 2H, CH.sub.2). .sup.13C NMR (100 MHz, CDCl.sub.3): 165.47, 137.03, 136.86, 133.88, 133.75, 133.33, 131.09, 129.30, 129.06, 128.73, 126.02, 125.66, 125.09, 122.76, 121.21, 120.04, 118.98, 52.02. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.15BrN.sub.2O.sub.3S: 443.0069, found: 443.0057; LC-MS: ret. time 5.571.

Example 68

[0220] 2-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)-N-cyclohexyl-N-methylacetamide. The appropriate compound of general formula 7a (2-(9-Bromo-5,5-dioxido-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetic acid; Example 65) (0.59 g, 1.6 mmol) was chlorinated as above reported and the corresponding acyl chloride, solubilized in dry DMF (8 mL), was added drop-wise, under N.sub.2 atmosphere, to a solution of N-methylcyclohexylamine (0.83 mL, 6.4 mmol) in dry DMF (2 mL) at rt. The mixture was heated to 40 C. for 1.5 h, then poured into ice-water, and acidified with 2N HCl to pH 3. The precipitate was filtered and purified by flash column chromatography, eluting with CHCl.sub.3, and subsequent trituration with petroleum ether/Et.sub.2O to give target compound SM8 (0.197 g, 30%) as a white solid: mp 170-172 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): (mixture of rotamers) 8.42 (d, J=1.7 Hz, 1H, ArH), 8.30 (d, J=8.0 Hz, 1H, ArH), 7.87 (d, J=7.8 Hz, 1H, ArH), 7.82 (t, J=7.6 Hz, 1H, ArH), 7.75-7.65 (m, 2H, ArH), 7.43 (t, J=8.9 Hz, 1H, H-7), 4.97 (s, 0.88H, NCH.sub.2), 4.90 (s, 1.12H, NCH.sub.2), 4.00-3.90 (m, 0.54H, Cy-CH), 3.60-3.50 (m, 0.46H, Cy-CH), 2.80 (s, 1.68H, NCH.sub.3), 2.60 (s, 1.32H, NCH.sub.3), 1.75-0.95 (m, 10H, Cy-CH.sub.2). .sup.13C NMR (100 MHz, DMSO-d.sub.6): (mixture of rotamers) 165.91, 165.87, 138.45, 138.32, 135.56, 135.52, 133.15, 133.11, 132.94, 132.91, 131.09, 129.59, 128.36, 126.96, 126.92, 123.76, 123.73, 121.54, 121.48, 117.71, 117.65, 55.11, 52.84, 50.10, 30.59, 29.48, 28.68, 27.38, 25.61, 25.45, 25.30, 25.15. HRMS (ESI) calcd for C.sub.21H.sub.23BrN.sub.2O.sub.3S [M.sup.++H].sup.+: 463.0692, found: 463.0678. LC-MS: ret. time 6.034. The two rotamers collapsed to one molecule after recording the NMR spectrum at 50 C.

Example 69

[0221] ##STR00105##

[0222] 2-(3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetic acid (7a(Int-1)) and 2-(3-ethoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetic acid (7a(Int-2)): A stirred mixture of compound of formula 6a(Int-1) (0.40 g, 0.99 mmol) in aqueous 10% NaOH (3 mL) and EtOH (3 mL) was refluxed for 30 min. After cooling, the organic solvent was evaporated under reduced pressure and the residue was poured into ice-water and acidified with 2N HCl (pH=2). The formed precipitate was filtered off to give a mixture of two compounds (7a(Int-1) and 7a(Int-2) in a 1:1 ratio as highlighted by the presence of two spots in TLC (CHCl.sub.3:MeOH 8:2) and also confirmed by .sup.1H-NMR spectrum. .sup.1H NMR (400 MHz, CDCl.sub.3): 8.20 (bs, 0.5H, H-10), 8.17 (bs, 0.5H, H-10), 7.90 (dd, J=5 and 9 Hz, 0.5H, H-1), 7.85 (d, J=9 Hz, 0.5H, H-1), 7.73-7.60 (m, 1H, H-4 and H-8), 7.60 (d, J=8.5 Hz, 0.5H, H-8), 7.45 (m, 0.5H, H-2), 7.40 (s, 0.5H, H-4), 7.35 (d, J=8 Hz, 0.5H, H-7), 7.20-7.30 (m, 1H, H-2 and H-7), 4.67 (s, 1H, NCH.sub.2), 4.65 (s, 1H, NCH.sub.2), 4.10 (q, J=7.0 Hz, 1H, OCH.sub.2), 1.45 (t, J=7.0 Hz, 1.5H, CH.sub.3). The compounds 7a(Int-1) and 7a(Int-2) were obtained as an orange solid that was used as such in the successive amidation step.

Example 70

[0223] Scheme 6: Preparation of target compounds deriving from intermediates of general formula 7a not included in Scheme 1.

##STR00106##

[0224] N-cyclohexyl-2-(3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetamide (SM882) and N-cyclohexyl-2-(3-ethoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetamide (SM883): A stirred mixture of 7a(Int-1) and 7a(Int-2) (0.50 g, 1.33 mmol), cyclohexylamine (0.18 mL, 1.6 mmol), TBTU (0.55 g, 1.7 mmol), and DIPEA (0.93 mL, 5.33 mmol) in dry CH.sub.2Cl.sub.2 (3 mL) was reacted at room temperature for 1 h. The solvent was then evaporated to dryness and the residue was poured in ice-water obtaining a precipitate that was filtered and the crude was purified by flash chromatography eluting with CH.sub.2Cl.sub.2 obtaining SM882 (R.sub.f>) and SM883 (R.sub.f<) respectively.

[0225] Each compound was further purified by crystallization with EtOH to give: SM882: white solid (0.064 g, 14%), mp 232-233 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 1.10-1.20 and 1.30-1.40 (m, each 2H, cyclohexyl CH.sub.2), 1.50-1.70 (m, 4H, cyclohexyl CH.sub.2), 1.80-1.90 (m, 2H, cyclohexyl CH.sub.2), 3.85-3.95 (m, 1H, cyclohexyl CH), 4.55 (s, 1H, NCH.sub.2), 6.45 (d, J=7.5 Hz, 1H, CONH), 7.40 (d, J=8.5 Hz, 1H, ArH), 7.55 (dt, J=2.6 and 8.1 Hz, 1H, ArH), 7.75-7.85 (m, 2H, ArH), 8.10 (dd, J=4.6 and 8.9 Hz, 1H, ArH), 8.30 (s, 1H, ArH); .sup.13C NMR (101 MHz, CDCl.sub.3): 24.2, 25.2, 32.4, 48.5, 51.4, 109.8 (d, J.sub.C-F=25.4 Hz), 119.8, 120.8 (d, J.sub.C-F=22.2 Hz), 122.7 (d, J.sub.C-F=3.6 Hz), 123.5, 128.8 (q, J.sub.C-F=273.3 Hz), 127.1 (d, J.sub.C-F=3.3 Hz), 127.4, 127.7, 128.5 (d, J.sub.C-F=8.1 Hz), 135.4 (d, J.sub.C-F=7.3 Hz), 140.1, 162.2 (d, J.sub.C-F=256.9 Hz), 165.6. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.21H.sub.20F.sub.4N.sub.2O.sub.3S: 457.1210, found: 457.1207.

[0226] SM883: white solid (0.069 g, 15%), mp 201-202 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 1.10-1.20 (m, 4H, cyclohexyl CH.sub.2), 1.30-1.40 (m, 2H, cyclohexyl CH.sub.2), 1.50 (t, J=6.9 Hz, 3H, OCH.sub.2CH.sub.3), 1.60-1.70 and 1.80-1.90 (m, each 2H, cyclohexyl CH.sub.2), 3.80-3.90 (m, 1H, cyclohexyl CH), 4.20 (q, J=6.9 Hz, 2H, OCH.sub.2CH.sub.3), 4.55 (s, 1H, NCH.sub.2), 6.55 (d, J=7.7 Hz, 1H, CONH), 7.30-7.40 (m, 2H, ArH), 7.50 (d, J=2.1 Hz, 1H, ArH), 7.70 (d, J=8.6 Hz, 1H, ArH), 7.95 (d, J=8.9 Hz, 1H, ArH), 8.25 (s, 1H, ArH); .sup.13C NMR (101 MHz, CDCl.sub.3): 14.4, 24.2, 25.2, 32.3, 48.4, 51.2, 64.4, 106.1, 119.3, 121.1, 122.1 (d, J.sub.C-F=3.6 Hz), 123.9, 126.1 (d, J.sub.C-F=3.3 Hz), 127.5, 134.9, 139.6, 159.6, 166.0. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.23H.sub.25F.sub.3N.sub.2O.sub.4S: 483.1566, found: 483.1565.

Example 71

[0227] N-(1-Ethylpropyl)-2-[3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM884): A stirred mixture of 3-Fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetic acid of formula 7a (Example 63; 0.30 g, 0.8 mmol), 3-aminopentane (0.084 g, 0.96 mmol), TBTU (0.33 g, 1.04 mmol), DIPEA (0.56 mL, 3.2 mmol) in CH.sub.2Cl.sub.2 (6 mL) was kept at room temperature for 3 h.

[0228] The organic solvent was evaporated and the residue was poured into ice/water and the mixture was acidified with 2N HCl (pH=4) maintaining the mixture under stirring for 40 min. until a precipitated was observed. The precipitate was filtered, dried and crystallized by cyclohexane/EtOAc (3:1 ratio) to obtain SM884 as pinkish solid in 34%: mp 184-185 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 0.80 (t, J=7.4 Hz, 6H, pentyl CH.sub.3), 1.30-1.40 and 1.45-1.55 (m, each 2H, pentyl CH.sub.3), 3.75-3.80 (m, 1H, pentyl CH), 4.50 (s, 1H, NCH.sub.2), 6.25 (d, J=8.6 Hz, 1H, CONH), 7.40 (d, J=8.6 Hz, 1H, ArH), 7.50 (dt, J=2.6 and 8.3 Hz, 1H, ArH), 7.70-7.75 (m, 2H, ArH), 8.10 (dd, J=4.6 and 8.9 Hz, 1H, ArH), 8.25 (s, 1H, ArH); .sup.13C NMR (100 MHz, CDCl.sub.3): 9.9, 27.0, 51.4, 52.7, 109.8 (d, J.sub.C-F=25.5 Hz), 119.8, 120.9 (d, J.sub.C-F=22.3 Hz), 122.7 (d, J.sub.C-F=3.5 Hz), 123.4, 126.1 (q, J.sub.C-F=273.0 Hz), 127.1 (d, J.sub.C-F=3.2 Hz), 127.7, 128.6 (d, J.sub.C-F=8.1 Hz), 135.3 (d, J.sub.C-F=7.3 Hz), 140.1, 162.2 (d, J.sub.C-F=257.0 Hz), 166.4. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.20F.sub.4N.sub.2O.sub.3S: 445.1210, found: 445.1207.

Example 72

[0229] 2-[3-Fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-(tetrahydro-2H-pyran-4-yl)acetamide (SM885): following the procedure reported above for compound SM884 and using tetrahydro-2H-pyran-4-amine, the target compound was obtained after crystallization by cyclohexane/EtOAc, in 34% yield as pale pink solid: mp 241-242 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 1.40-1.50, 1.80-1.90, 3.40-3.50, and 3.75-3.85 (m, each 2H, pyran CH.sub.2), 4.00-4.10 (m, 1H, pyran CH), 4.50 (s, 1H, NCH.sub.2), 6.45 (d, J=7.4 Hz, 1H, CONH), 7.40 (d, J=8.6 Hz, 1H, ArH), 7.50 (dt, J=2.7 and 8.5 Hz, 1H, ArH), 7.65-7.75 (m, 2H, ArH), 8.05 (dd, J=4.6 and 8.9 Hz, 1H, ArH), 8.25 (s, 1H, ArH); .sup.13C NMR (100 MHz, CDCl.sub.3): 32.4, 46.0, 51.3, 66.2, 109.8 (d, J.sub.C-F=25.5 Hz), 119.7, 121.0 (d, J.sub.C-F=22.2 Hz), 122.7 (d, J.sub.C-F=3.5 Hz), 123.4, 126.1 (q, J.sub.C-F=273.0 Hz), 127.2, 127.4 (d, J.sub.C-F=3.2 Hz), 127.8, 128.6 (d, J.sub.C-F=8.1 Hz), 135.3 (d, J.sub.C-F=7.3 Hz), 140.0, 162.2 (d, J.sub.C-F=257.2 Hz), 166.0. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.18F.sub.4N.sub.2O.sub.4S: 459.1002, found: 459.1002.

Example 73

[0230] 2-[3-Fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-morpholin-4-ylacetamide (SM881): following the procedure reported for compound SM884 and using morpholin-4-amine, the target compound was obtained after crystallization by EtOH, in 34% yield as pale pink solid: mp 276-278 C. Two rotamers were identified by .sup.1H-NMR and they collapsed to one molecule carrying out experiments at 60 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6, 25 C.): 2.50-2.60, 2.75-2.95, 3.40-3.50, and 3.60-3.80 (m, each 2H, morpholine CH.sub.2), 4.50 and 5.00 (s, each 1H, NCH.sub.2), 7.60-7.75 (m, 2H, ArH), 7.75-7.80 and 7.80-7.90 (m, each 1H, ArH), 8.45 (dd, J=4.6 and 8.6 Hz, 1H, ArH), 8.55 (s, 1H, ArH), 8.80 and 9.25 (s, each 0.5H, CONH); .sup.13C NMR (100 MHz, DMSO-d.sub.6): 32.4, 46.0, 66.2, 110.1 (d, J.sub.C-F=25.5 Hz), 119.7, 122.0 (d, J.sub.C-F=22.2 Hz), 123.7 (d, J.sub.C-F=3.5 Hz), 123.4, 125.1 (q, J.sub.C-F=273.0 Hz), 127.2, 127.4 (d, J.sub.C-F=3.2 Hz), 127.8, 129.2 (d, J.sub.C-F=8.1 Hz), 134.2 (d, J.sub.C-F=7.3 Hz), 140.0, 161.2 (d, J.sub.C-F=257.2 Hz), 166.0. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.19H.sub.17F.sub.4N.sub.3O.sub.4S: 460.0955, found: 460.0954.

Example 74

[0231] N-(2-chloropyridin-4-yl)-2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM880): The title compound was prepared starting from 2-(5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetic acid of formula 7a (Example 75) and following the procedure reported for compound SM884 and using 2-chloro-4-pyridineamine. Title compound was obtained after crystallization by cyclohexane/EtOAc, as pale pink solid in 34% yield: mp 184-185 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 0.80 (t, J=7.4 Hz, 6H, pentyl CH.sub.3), 1.30-1.40 and 1.45-1.55 (m, each 2H, pentyl CH.sub.3), 3.75-3.80 (m, 1H, pentyl CH), 4.50 (s, 1H, NCH.sub.2), 6.25 (d, J=8.6 Hz, 1H, CONH), 7.40 (d, J=8.6 Hz, 1H, ArH), 7.50 (dt, J=2.6 and 8.3 Hz, 1H, ArH), 7.70-7.75 (m, 2H, ArH), 8.10 (dd, J=4.6 and 8.9 Hz, 1H, ArH), 8.25 (s, 1H, ArH); .sup.13C NMR (101 MHz, CDCl.sub.3): 9.9, 27.0, 51.4, 52.7, 109.8 (d, J.sub.C-F=25.5 Hz), 119.8, 120.9 (d, J.sub.C-F=22.3 Hz), 122.7 (d, J.sub.C-F=3.5 Hz), 123.4, 126.1 (q, J.sub.C-F=273.0 Hz), 127.1 (d, J.sub.C-F=3.2 Hz), 127.7, 128.6 (d, J.sub.C-F=8.1 Hz), 135.3 (d, J.sub.C-F=7.3 Hz), 140.1, 162.2 (d, J.sub.C-F=257.0 Hz), 166.4. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.20H.sub.20F.sub.4N.sub.2O.sub.3S: 445.1210, found: 445.1207.

[0232] Scheme 7: Preparation of target compounds deriving from intermediates of general formula 7a, not included in Scheme 1.

##STR00107##

Example 75

[0233] 2-(5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetic acid (7a(Int-3)): compound of formula 7a(Int-3) was prepared from ethyl [5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetate according to the procedure reported for a similar compound described in Example 65. The intermediate was obtained as brown solid in 81% yield: .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.55 (d, J=2.2 Hz, 1H, ArH), 8.27 (d, J=8.0 Hz, 1H, ArH), 8.00-7.75 (m, 4H, ArH), 7.50-7.50 (m, 2H, ArH), 4.75 (s, 2H, NCH.sub.2).

Example 76

[0234] N-(1-benzylpiperidin-4-yl)-2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide of formula 8a(Int-3): to a solution of 2-(5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl)acetic acid of formula 7a(Int-3) (Example 75; 0.280 g, 0.78 mmol) in dry CH.sub.2Cl.sub.2 (10 mL), N-benzyl-4-aminopiperidine (0.180 g, 0.94 mmol), TBTU (0.376 g, 0.12 mmol), and DIPEA (0.510 mL, 0.31 mmol) were added. The reaction mixture was stirred at room temperature for 4 h and then poured into ice-water and acidified with 2N HCl (pH=2). The mixture was extracted with CH.sub.2Cl.sub.2 (330 mL) and the combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a brown oil which was purified by flash column chromatography (CHCl.sub.3/MeOH 95:5), to afford N-(1-benzylpiperidin-4-yl)-2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide as solid in 45% yield: mp C. .sup.1H-NMR (200 MHz, CDCl.sub.3): 8.27 (s, 1H, ArH), 8.03-7.99 (d, J=7.9 Hz, 2H, ArH), 7.82-7.60 (m, 3H, ArH), 7.32-7.15 (m, 6H, ArH), 6.53 (d, J=7.3 Hz, 1H, NH), 4.54 (s, 2H, benzylic-CH.sub.2), 4.83-4.71 (m, 1H, piperidine-CH), 3.45 (s, 2H, CH.sub.2), 2.67-2.62 (m, 2H, piperidine-CH.sub.2), 2.15-1.80 (m, 6H, piperidine-CH.sub.22), 1.47-1.32 (m, 2H, piperidine-CH.sub.2).

Example 77

[0235] 2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-piperidin-4-ylacetamide of general formula 8a (SM655): to a solution of the appropriate compound of formula 8a (0.180 g, 0.34 mmol) in EtOH (20 mL), Pd/C (20% w/w, 0.036 g) was added. The reaction mixture was stirred at room temperature for 7 h under H.sub.2 bubbling. The mixture was filtered over Celite and the filtrate was evaporated to dryness to give a brown solid which was crystallized by EtOH to afford SM665 as white solid in 27% yield. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.55 (s, 1H, ArH), 8.38-8.35 (m, 2H, ArH), 7.91-7.81 (m, 3H, ArH), 7.71 (t, J=7.6 Hz, 1H, ArH), 7.62 (d, J=8.6 Hz, 1H, ArH), 4.63 (s, 2H, benzylic-CH.sub.2), 3.70-3.59 (m, 1H, piperidine-CH), 3.16-3.13 (m, 2H, piperidine-CH.sub.2), 2.82 (t, J=10.7 Hz, 2H, piperidine-CH.sub.2), 1.77-1.74 (m, 2H, piperidine-CH.sub.2), 1.49-1.37 (m, 2H, piperidine-CH.sub.2).

[0236] Scheme 8: Preparation of target compounds deriving from intermediates of general formula 7a, not included in scheme 1.

##STR00108##

Example 78

[0237] 2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-(trans-4-hydroxycyclohexyl)acetamide of formula 8a(Int-4): to a solution of compound of formula 7a(Int-3) (Example 75; 0.100 g, 0.30 mmol) in dry CH.sub.2Cl.sub.2 (4 mL), trans-4-aminocyclohexanol (0.041 g, 0.36 mmol), BOP (0.199 g, 0.45 mmol), and DIPEA (0.200 mL, 1.2 mmol) were added at 0 C. The reaction mixture was stirred at room temperature for 12 h, then it was concentrated under vacuum and poured into ice-water and acidified with 2N HCl (pH=4). The mixture was extracted with EtOAc (320 mL) and the combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a brown solid which was crystallized by EtOH to afford SM588 8a(Int-4) as a white solid in 88% yield: mp 212-213 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.29 (d, J=1.3 Hz, 1H, ArH), 8.03 (d, J=7.3 Hz, 2H, ArH), 7.81 (td, J=1.3 and 7.4 Hz, 1H, ArH), 7.72 (dd, J=1.6 and 6.3 Hz, 1H, ArH), 6.67 (t, J=7.5 Hz, 1H, ArH), 7.33 (d, J=7.9 Hz, 1H, ArH), 6.52 (d, J=7.6 Hz, 1H, NH), 4.51 (s, 2H, benzyl-CH.sub.2), 3.85-3.77 (m, 1H, cyclohexyl-CH), 3.61-3.46 (m, 1H, cyclohexyl-CH), 1.99-1.89 (m, 4H, cyclohexyl-CH.sub.22), 1.46 (s, 1H, OH), 1.42-1.34 (m, 2H, cyclohexyl-CH.sub.2), 1.23-1.16 (m, 2H, cyclohexyl-CH.sub.2).

Example 79

[0238] trans-4-({2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetyl}amino)cyclohexyl 4-nitrobenzenesulfonate of general formula 8a (SM589): to a solution of an appropriate compound SM588 of formula 8a(Int-4) (0.350 g, 0.77 mmol) in dry CH.sub.2Cl.sub.2 (6 mL), 4-nitrobenzenesulfonyl chloride (0.355 g, 1.60 mmol), DMAP (0.094 g, 0.77 mmol), and ET.sub.3N (0.320 mL, 2.30 mmol) were added at 0 C. The reaction mixture was stirred at room temperature for 2 h, then it was concentrated under vacuum and poured into ice-water and acidified with 2N HCl (pH=4). The mixture was extracted with CH.sub.2Cl.sub.2 (320 mL) and the combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a white solid which was crystallized by EtOH to afford SM589 as a white solid in 38% yield: mp 151-152 C. .sup.1H-NMR (400 MHz, CDCl.sub.3): 8.35 (d, J=8.5 Hz, 2H, ArH), 8.29 (s, 1H, ArH), 8.12-7.93 (m, 4H, ArH), 7.81 (t, J=7.0 Hz, 1H, ArH), 7.72-7.61 (m, 2H, ArH), 7.26 (d, J=8.6 Hz, 1H, ArH), 6.64 (d, J=7.5 Hz, 1H, NH), 4.60-4.51 (m, 1H, cyclohexyl-CH), 4.49 (s, 2H, CH.sub.2), 3.91-3.85 (m, 1H, cyclohexyl-CH), 2.01-1.88 (m, 4H, each 2H cyclohexyl-CH.sub.2), 1.68-1.59 (m, 2H, cyclohexyl-CH.sub.2), 1.52 (s, 1H, OH), 1.32-1.10 (m, 2H, cyclohexyl-CH.sub.2).

Example 80

[0239] trans-4-({2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetyl}amino)cyclohexyl 4-aminobenzenesulfonate of formula 8a (SM656): to a solution of compound SM589 (0.400 g, 0.63 mmol) in DMF (30 mL), Raney/Ni (10% w/w, 0.046 g) was added. The reaction mixture was stirred at room temperature for 2 h under H.sub.2 bubbling. The mixture was filtered over Celiteand the filtrate was evaporated to dryness to give a brown solid which was crystallized by EtOH to afford SM656 as brownish solid in 58% yield. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.45 (s, 1H, ArH), 8.37 (d, J=7.9 Hz, 1H, ArH), 8.05 (d, J=7.2 Hz, 1H, ArH), 7.90-7.80 (m, 3H, ArH and NH), 7.70 (t, J=7.6 Hz, 1H, ArH), 7.57 (d, J=8.4 Hz, 1H, ArH), 7.44 (d, J=8.8 Hz, 2H, ArH), 6.59 (d, J=8.6 Hz, 2H, ArH), 6.19 (s, 2H, NH.sub.2), 4.58 (s, 2H, CH.sub.2), 4.11-4.23 (m, 1H, cyclohexyl-CH), 1.69-1.61 (m, 4H, each 2H, cyclohexyl-CH.sub.2), 1.39-1.31 (m, 2H, cyclohexyl-CH.sub.2), 1.17-1.08 (m, 2H, cyclohexyl-CH.sub.2).

Example 81

[0240] 2-(3-acetyl-4-hydroxy-1,1-dioxido-2H-1,2-benzothiazin-2-yl)-N-cyclohexylacetamide (12a) (Scheme 4). A mixture of 11a, prepared according to literature, (0.63 g, 2.11 mmol), cyclohexylamine (0.53 mL, 4.66 mmol), TBTU (1.63 g, 5.08 mmol), and Et.sub.3N (4 equiv.) in dry THE was reacted at room temperature for 2 h. The reaction mixture was then poured in ice-water and acidified with 2N HCl (pH=4) obtaining a precipitate that was filtered and dried to give 12a (0.75 g, 94%) as pale-yellow solid. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 0.80-1.20 and 1.40-1.60 (m, each 5H, cyclohexyl CH.sub.2), 2.40 (s, 3H, CH.sub.3), 4.00 (s, 2H, NCH.sub.2), 7.75-7.85 (m, 4H, ArH and CONH), 7.95-8.10 (m, 1H, ArH), 15.20 (bs, 1H, OH).

Example 82

[0241] N-cyclohexyl-2-(3-methyl-5,5-dioxidopyrazolo[4,3-c][1,2]benzothiazin-4 (1H)-yl)acetamide (SM879). The mixture of 12a (0.30 g, 0.79 mmol) and hydrazine monohydrate (0.19 mL, 3.96 mmol) was reacted at 60 C. for 1 h. After cooling, the reaction mixture was poured in ice-water and acidified with 2N HCl (pH=4), yielding a precipitate that was filtered and purified by flash chromatography eluting with CH.sub.2Cl.sub.2:MeOH 97:3 followed by crystallization by EtOH to afford SM879 (0.08 g, 54%) as a white solid. .sup.1H NMR (400 MHz, CDCl.sub.3) 1.10-1.20 and 1.25-1.45 (m, each 2H, cyclohexyl CH.sub.2), 1.50-1.75 (m, 4H, cyclohexyl CH.sub.2), 2.80-2.90 (m, 2H, cyclohexyl CH.sub.2), 2.30 (s, 1H, CH.sub.3), 3.75 (m, 1H, cyclohexyl CH), 4.05 (s, 2H, NCH.sub.2), 6.50 (d, J=8.1 Hz, 1H, NH), 7.55 (dt, J=1.2 and 7.8 Hz, 1H, ArCH), 7.70 (dt, J=1.2 and 7.7 Hz, 1H, ArCH), 7.80 (dd, J=0.9 and 7.8 Hz, 1H, ArCH), 7.95 (d, J=7.3 Hz, 1H, ArCH), 10.50 (bs, 1H, CONH). HRMS (ESI) m/z [M+H].sup.+ calcd for C.sub.24H.sub.31N.sub.3O.sub.4S: 375.1460, found: 375.1485; LC-MS: ret. time 4.109 min.

Example 83

Scheme 9: Synthetic Procedure for the Preparation of Target Compound SM886.

[0242] ##STR00109##

[0243] N-(4-aminocyclohexyl)-2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM886). A stirred mixture of [5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetic acid of formula 7a(Int-3) (0.10 g, 0.28 mmol), trans-1,4-diaminocyclohexane (0.32 g, 2.80 mmol), TBTU (0.12 g, 0.36 mmol), DIPEA (0.19 mL, 1.12 mmol) in dry DMF (3 mL) was kept at room temperature for 3 h. The reaction mixture was poured into ice/water and extracted with CH.sub.2Cl.sub.2 (3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a brown oil. After purification by trituration with Et.sub.2O, the title compound was obtained as a yellow solid in 16% yield: m.p. 212-214 C. .sup.1H NMR (400 MHz, MeOD): 1.16-1.29 (m, 4H, CH.sub.22), 1.87-1.89 (m, 4H, CH.sub.22), 2.60-2.63 (m, 1H, CH), 3.49-3.54 (m, 1H, CH), 4.66 (s, 2H, NCH.sub.2), 7.57 (d, J=8.6 Hz, 1H, ArH), 7.73 (t, J=7.5 Hz, 1H, ArH), 7.82-7.89 (m, 2H, ArH), 7.99 (d, J=7.8 Hz, 1H, ArH), 8.24 (d, J=8.0 Hz, 1H, ArH), 8.49 (s, 1H, ArH). HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.21H.sub.22F.sub.3N.sub.3O.sub.3S: 454.1412, found: 454.14162.

Example 84

[0244] Scheme 10: Synthetic procedure for the preparation of target compound SM887.

##STR00110##

[0245] Dimethyl 3-({[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetyl}amino)pentanedioate (8a(Int-5)). A stirred mixture of [5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetic acid of formula 7a(Int3) (0.33 g, 0.92 mmol), dimethyl 3-aminopentanedioate (0.19 g, 1.11 mmol), TBTU (0.38 g, 1.19 mmol), DIPEA (0.64 mL, 3.68 mmol) in CH.sub.2Cl.sub.2 (10 mL) was kept at room temperature for 2 h. The organic solvent was evaporated, and the residue was poured into ice/water and extracted with EtOAc (3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a brown oil. After purification by flash column chromatography, eluting with CHCl.sub.3/MeOH (98:2), the title compound was obtained as a white solid in 25% yield: m.p. 126-128 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 2.37-2.44 (m, 4H, CH.sub.22), 3.58 (s, 6H, OCH.sub.32), 4.52 (s, 2H, NCH.sub.2), 4.59-4.64 (m, 1H, CH), 7.17 (d, J=8.4 Hz, 1H, NH), 7.40 (d, J=8.5 Hz, 1H, H-7), 7.65 (t, J=7.8 Hz, 1H, H-3), 7.72 (d, J=8.5 Hz, 1H, H-8), 7.79 (td, J=1.0 and 7.4 Hz, 1H, H-2), 8.02 (d, J=8.1 Hz, 2H, H-1 and H-4), 8.27 (s, 1H, H-10).

[0246] 2-[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-[3-hydroxy-1-(2-hydroxyethyl)propyl]acetamide (SM887). A stirred mixture of dimethyl 3-({[5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetyl}amino)pentanedioate of formula 8a(Int-5) (0.45 g, 0.87 mmol) and NaBH.sub.4 (1.32 g, 35.97 mmol) in dry THE (20 mL) was stirred at reflux for 16 h. Then, the reaction mixture was cooled up to 0 C. and MeOH (15 mL) was added to quench the excess of NaBH.sub.4. The organic solvent was evaporated and the residue was poured into ice/water and extracted with EtOAc (3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a yellow oil. After purification by flash column chromatography, eluting with CHCl.sub.3/MeOH (98:2), the title compound was obtained as a white solid in 28% yield: m.p. 136-138 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 1.45-1.58 (m, 4H, CH.sub.22), 3.29-3.39 (m, 4H, CH.sub.22), 3.76-3.78 (m, 1H, CH), 4.30 (t, J=5.1 Hz, 2H, OH2), 4.66 (s, 2H, NCH.sub.2), 7.65 (d, J=8.5 Hz, 1H, H-7), 7.76 (t, J=7.5 Hz, 1H, H-3), 7.86-7.93 (m, 2H, ArH), 7.97 (d, J=7.2 Hz, 1H, ArH), 8.01 (d, J=8.6 Hz, 1H, NH), 8.43 (d, J=7.9 Hz, 1H, ArH), 8.60 (s, 1H, H-10). .sup.13C NMR (101 MHz, DMSO-d.sub.6): 38.0, 44.1, 49.7, 58.2, 121.6, 121.7, 123.3, 124.4 (q, J.sub.C-F=268.4 Hz), 124.7, 125.6 (q, J.sub.C-F=32.6 Hz), 127.1, 127.2, 129.9, 130.9, 133.2, 135.0, 141.9, 166.2. HRMS (ESI) m/z [M+K].sup.+ calcd. for C.sub.20H.sub.21F.sub.3N.sub.205S: 497.0760, found: 497.0756.

Example 85

Scheme 11: Synthetic Procedure for the Preparation of Target Compound SM888.

[0247] ##STR00111##

[0248] Alternative procedure for the synthesis of [3-Fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetic acid (7a(Int-1)). A stirred mixture of compound of formula 6a(Int-1) (1.25 g, 3.10 mmol) in aqueous 1N LiOH (15.5 mL, 15.5 mmol) and dioxane (30 mL) was kept at room temperature for 30 min. The reaction mixture was poured into ice-water and acidified with 2N HCl (pH=2). The formed precipitate was filtered off and dried to give the title compound in 98% yield: m.p. 100-102 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 4.72 (s, 2H, NCH.sub.2), 7.33 (d, J=8.4 Hz, 1H, ArH), 7.45 (td, J=2.5 and 8.1 Hz, 1H, H-2), 7.65-7.72 (m, 2H, ArH), 7.98 (dd, J=4.4 and 8.6 Hz, 1H, H-1), 8.21 (s, 1H, H-10).

[0249] Dimethyl 3-({[3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetyl}amino)pentanedioate (8a(Int-6)). A stirred mixture of [3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetic acid of formula 7a(Int-1) (0.71 g, 1.9 mmol), dimethyl 3-aminopentanedioate (0.40 g, 2.28 mmol), TBTU (0.79 g, 2.47 mmol), DIPEA (1.32 mL, 7.6 mmol) in CH.sub.2Cl.sub.2 (30 mL) was kept at room temperature for 2 h. The organic solvent was evaporated and the residue was poured into ice/water and the mixture was acidified with 2N HCl (pH=4) maintaining the mixture under stirring for 10 min. until a precipitated was observed. The precipitate was filtered to give the title compound as a white solid in 87%: m.p. 153-155 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 2.60-2.69 (m, 4H, CH.sub.22), 3.89 (s, 6H, OCH.sub.32), 4.57 (s, 2H, NCH.sub.2), 4.64-4.66 (m, 1H, CH), 7.14 (d, J=8.5 Hz, 1H, NH), 7.48 (d, J=8.4 Hz, 1H, ArH), 7.54 (td, J=2.3 and 8.4 Hz, 1H, ArH), 7.75-7.77 (m, 2H, ArH), 8.07 (dd, J=4.7 and 8.9 Hz, 1H, ArH), 8.26 (s, 1H, ArH). 2-[3-Fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-[3-hydroxy-1-(2-hydroxyethyl)propyl]acetamide (SM888). A stirred mixture of dimethyl 3-({[3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetyl}amino)pentanedioate of formula 8a(Int-6) (0.45 g, 0.85 mmol) and NaBH.sub.4 (1.28 g, 33.81 mmol) in dry THE (15 mL) was stirred at reflux for 30 h. Then, the reaction mixture was cooled up to 0 C. and MeOH (15 mL) was added to quench the excess of NaBH.sub.4. The organic solvent was evaporated and the residue was poured into ice/water and extracted with EtOAc (3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a yellow oil. After purification by flash column chromatography, eluting with cyclohexane/EtOAc (70:30), the title compound was obtained as a white solid in 9% yield: m.p. 136-138 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 1.43-1.58 (m, 4H, CH.sub.22), 3.27-3.34 (m, 4H, CH.sub.22), 3.74-3.76 (m, 1H, CH), 4.30 (t, J=5.1 Hz, 2H, OH2), 4.66 (s, 2H, NCH.sub.2), 7.69 (d, J=8.5 Hz, 1H, H-7), 7.76 (td, J=2.7 and 8.7 Hz, 1H, H-2), 7.84 (dd, J=2.7 and 8.6 Hz, 1H, H-4), 7.91 (dd, J=1.6 and 8.5 Hz, 1H, H-8), 8.02 (d, J=8.6 Hz, 1H, NH), 8.51 (dd, J=4.4 and 8.3 Hz, 1H, H-1), 8.60 (s, 1H, H-10). .sup.13C NMR (101 MHz, DMSO-d.sub.6): 38.2, 44.3, 50.7, 58.3, 109.1 (d, J.sub.C-F=25.5 Hz), 120.8 (d, J.sub.C-F=22.1 Hz), 122.5, 123.5, 124.5 (q, J.sub.C-F=274.0 Hz), 124.7, 126.1 (q, J.sub.C-F=33.2 Hz), 127.2, 127.9, 130.7 (d, J.sub.C-F=8.4 Hz), 136.7 (d, J.sub.C-F=7.5 Hz), 141.7, 162.3 (d, J.sub.C-F=252.8 Hz), 166.4. HRMS (ESI) m/z [M+Na].sup.+ calcd. for C.sub.20H.sub.20F.sub.4N.sub.2O.sub.5S: 499.09267, found: 499.09354.

Example 86

[0250] N-{1-[(dimethylamino)methyl]propyl}-2-[3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM889). A stirred mixture of [3-fluoro-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetic acid of formula 7a(Int-1) (0.30 g, 0.8 mmol), (2-aminobutyl)dimethylamine (0.13 mL, 0.96 mmol), TBTU (0.33 g, 1.04 mmol), DIPEA (0.56 mL, 3.2 mmol) in CH.sub.2Cl.sub.2 (30 mL) was kept at room temperature for 1 h. The organic solvent was evaporated, and the residue was poured into ice/water and extracted with EtOAc (3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a brown oil. After purification by flash column chromatography, eluting with CHCl.sub.3/MeOH (95:5), the title compound was obtained as a light brown solid in 17% yield: m.p. 167-169 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 0.88 (t, J=7.4 Hz, 3H, CH.sub.2CH.sub.3), 1.46-1.49 (m, 1H, CHCH.sub.2CH.sub.31/2), 1.60-1.62 (m, 1H, CHCH.sub.2CH.sub.31/2), 2.21-2.23 (m, 1H, CHCH.sub.2N1/2), 2.26-2.29 (m, 1H, CHCH.sub.2N1/2), 3.89-3.93 (m, CH, 1H), 4.46 (d, J=17.5 Hz, 1H, NCH.sub.21/2), 4.70 (d, J=17.5 Hz, 1H, NCH.sub.21/2), 6.46 (d, J=6.0 Hz, 1H, NH), 7.51-7.56 (m, 1H, H-2), 7.60 (d, J=8.6 Hz, 1H, H-7), 7.73-7.77 (m, 2H, H-4 and H-8), 8.07 (dd, J=4.5 and 8.8 Hz, 1H, H-1), 8.26 (s, 1H, H-10). .sup.13C NMR (101 MHz, CDCl.sub.3): 9.9, 25.9, 45.7, 49.3, 51.5, 62.5, 110.0 (d, J.sub.C-F=25.3 Hz), 120.8, 120.9 (d, J.sub.C-F=21.2 Hz), 122.7 (d, J.sub.C-F=3.0 Hz), 123.7 (q, J.sub.C-F=273.7 Hz), 123.9, 127.2, 127.7 (d, J.sub.C-F=3.0 Hz), 127.8 (q, J.sub.C-F=33.3 Hz), 128.7 (d, J.sub.C-F=8.0 Hz), 135.9 (d, J.sub.C-F=7.1 Hz), 140.5, 162.4 (d, J.sub.C-F=256.5 Hz), 166.8. HRMS (ESI) m/z [M+H].sup.+ calcd. for C.sub.21H.sub.23F.sub.4N.sub.3O.sub.3S: 474.1474, found: 474.14908.

Example 87

Scheme 12: Synthetic Procedure for the Preparation of the Intermediate of Formula 7a(Int-4).

##STR00112##

[0251] [3-Methoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetic acid (7a(Int-4)). A stirred mixture of compound of formula 6a(Int-2) (0.34 g, 0.76 mmol) in aqueous 10% NaOH (3 mL) and MeOH (3 mL) was stirred at reflux for 1 h. The reaction mixture was poured into ice/water and acidified with 2N HCl (pH=2). The formed precipitate was filtered off and dried to give the title compound in 46% yield; m.p. 184-186 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 3.47 (s, 3H, OCH.sub.3), 4.27 (s, 2H, NCH.sub.2), 7.38-7.41 (m, 2H, ArH), 7.55-7.58 (m, 1H, ArH), 7.76 (d, J=7.3 Hz, 1H, ArH), 8.31 (d, J=8.7 Hz, 1H, ArH), 8.45 (s, 1H, ArH).

Scheme 13: Synthetic Procedure for the Preparation of the Intermediates of Formula 8a(Int-7), 8a(Int-8) and 8a(Int-9).

##STR00113##

Example 88

[0252] N-cyclohexyl-2-[3-methoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (8a(Int-7)). A stirred mixture of 3-methoxy-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide of formula 7a(Int-4) (0.19 g, 0.48 mmol), cyclohexylamine (0.07 mL, 0.57 mmol), TBTU (0.20 g, 0.62 mmol), DIPEA (0.25 mL, 1.91 mmol) in dry CH.sub.2Cl.sub.2 (10 mL) was kept at room temperature for 2 h. The organic solvent was evaporated, and the residue was poured into ice/water. The obtained precipitate was filtered to give the title compound as a white solid in 58% yield: m.p. 184-185 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 1.14-1.22 (m, 4H, CH.sub.22), 1.32-1.41 (m, 2H, CH.sub.2), 1.63-1.66 (m, 2H, CH.sub.2), 1.86-1.89 (m, 2H, CH.sub.2), 3.87-3.89 (m, 1H, CH), 3.98 (s, 3H, OCH.sub.3), 4.55 (s, 2H, NCH.sub.2), 6.58 (d, J=7.3 Hz, 1H, NH), 7.34-7.38 (m, 2H, H-1 and H-2), 7.52 (d, J=2.4 Hz, 1H, H-4), 7.70 (d, J=8.6 Hz, 1H, H-8), 7.97 (d, J=8.8 Hz, 1H, H-7), 8.24 (s, 1H, H-10).

Example 89

[0253] 2-[3-Methoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-(tetrahydro-2H-pyran-4-yl)acetamide (8a(Int-8)). A stirred mixture of 3-methoxy-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide of formula 7a(Int-4) (0.45 g, 0.96 mmol), 4-aminotetrahydropyran (0.12 mL, 1.15 mmol), TBTU (0.40 g, 1.25 mmol), DIPEA (0.67 mL, 3.84 mmol) in dry CH.sub.2Cl.sub.2 (10 mL) was kept at room temperature for 2 h. The organic solvent was evaporated, and the residue was poured into ice/water. The obtained precipitate was filtered to give the title compound as a white solid in 55% yield: m.p. 118-120 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 1.07-1.24 (m, 2H, CH.sub.2), 1.29-1.40 (m, 1H, CH.sub.21/2), 1.59-1.65 (m, 1H, CH.sub.21/2), 3.23-3.42 (m, 3H, CH.sub.21/2 and CH.sub.2), 3.60-3.69 (m, 1H, CH), 3.75-3.80 (m, 1H, CH.sub.21/2), 3.93 (s, 3H, OCH.sub.3), 4.63 (s, 2H, NCH.sub.2), 7.38-7.40 (m, 2H, ArH and CONH), 7.56-7.63 (m, 1H, ArH), 7.78-7.84 (m, 1H, ArH), 8.21-8.25 (m, 1H, ArH), 8.35-8.33 (m, 1H, ArH), 8.50 (s, 1H, ArH).

Example 90

[0254] N-(1-ethylpropyl)-2-[3-methoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (8a(Int-9)). A stirred mixture of 3-methoxy-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide of formula 7a(Int-4) (0.45 g, 0.96 mmol), 3-aminopentane (0.13 mL, 1.15 mmol), TBTU (0.40 g, 1.25 mmol), DIPEA (0.67 mL, 3.84 mmol) in dry CH.sub.2Cl.sub.2 (10 mL) was kept at room temperature for 2 h. The organic solvent was evaporated, and the residue was poured into ice/water. The obtained precipitate was filtered to give the title compound as a white solid in 55% yield: m.p. 151-153 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 0.73 (t, J=6.7 Hz, 6H, CH.sub.32), 1.24-1.29 (m, 2H, CH.sub.2), 1.38-1.44 (m, 2H, CH.sub.2), 3.39-3.43 (m, 1H, CH), 3.93 (s, 3H, OCH.sub.3), 4.65 (s, 2H, NCH.sub.2), 7.39-7.42 (m, 2H, ArH and CONH), 7.63 (d, J=8.1 Hz, 1H, ArH), 7.83 (d, J=8.2 Hz, 1H, ArH), 7.89 (d, J=8.2 Hz, 1H, ArH), 8.35 (d, J=8.3 Hz, 1H, ArH), 8.50 (s, 1H, ArH).

Scheme 14: Synthetic Procedure for the Preparation of Target Compound SM890.

[0255] ##STR00114##

[0256] N-cyclohexyl-2-[3-hydroxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM890). To a solution of N-cyclohexyl-2-[3-methoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide 8a(Int-7) (0.13 g, 0.28 mmol) in dry CH.sub.2Cl.sub.2 (8 mL), 1M BBr.sub.3 in dry CH.sub.2Cl.sub.2 (0.84 mL, 0.84 mmol) was added dropwise at 0 C. and then, the reaction mixture was kept at 10 C. for 2 h.

[0257] The mixture was poured into ice/water and extracted in EtOAc (3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a brown solid. After purification by flash column chromatography, eluting with CHCl.sub.3/MeOH (99:1), the title compound was obtained as a little brown solid in 24% yield: m.p. 236-240 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 1.13-1.20 (m, 6H, CH.sub.23), 1.51-1.56 (m, 1H, CH), 1.65-1.67 (m, 4H, CH.sub.22), 4.60 (s, 2H, NCH.sub.2), 7.22-7.25 (m, 2H, ArH), 7.57 (d, J=8.3 Hz, 1H, ArH), 7.80 (d, J=7.9 Hz, 1H, NH), 8.06-8.09 (m, 1H, ArH), 8.22 (d, J=8.3 Hz, 1H, ArH), 8.43 (s, 1H, ArH), 10.78 (bs, 1H, OH). .sup.13C NMR (101 MHz, DMSO-d.sub.6): 24.7, 25.5, 32.6, 48.1, 49.8, 107.1, 120.7, 121.6, 121.7, 122.1 (2C), 124.5 (q, J.sub.C-F=272.9 Hz), 125.4 (q, J.sub.C-F=32.8 Hz), 125.6, 129.2, 136.2, 140.8, 158.9, 165.5. HRMS (ESI) m/z [M+Na].sup.+ calcd. for C.sub.21H.sub.21F.sub.3N.sub.204S: 477.1071, found: 477.10749.

Scheme 15: Synthetic Procedure for the Preparation of Target Compound SM891.

[0258] ##STR00115##

[0259] 2-[3-Hydroxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-(tetrahydro-2H-pyran-4-yl)acetamide (SM891). To a solution of 2-[3-methoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]-N-(tetrahydro-2H-pyran-4-yl)acetamide 8a(Int-8) (0.25 g, 0.52 mmol) in dry CH.sub.2Cl.sub.2 (6 mL), 1M BBr.sub.3 in dry CH.sub.2Cl.sub.2 (2.34 mL, 2.34 mmol) was added dropwise at 0 C. and then, the reaction mixture was kept at 10 C. for 24 h. The mixture was poured into ice/water and extracted in EtOAc (3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a brown solid. After purification by flash column chromatography, eluting with CHCl.sub.3/MeOH (98:2), the title compound was obtained as a little brown solid in 6% yield: m.p. 226-228 C. .sup.1H NMR (400 MHz, DMSO-d.sub.6): 1.30-1.39 (m, 2H, CH.sub.2), 1.62-1.65 (m, 2H, CH.sub.2), 3.26-3.32 (m, 2H, CH.sub.2O), 3.63-3.67 (m, 1H, CH), 3.77-3.80 (m, 2H, CH.sub.2O), 4.61 (s, 2H, NCH.sub.2), 7.21-7.24 (m, 2H, ArH), 7.58 (d, J=8.3 Hz, 1H, ArH), 7.81 (d, J=8.6 Hz, 1H, ArH), 8.21-8.24 (m, 2H, ArH and NH), 8.44 (s, 1H, ArH), 10.70 (bs, 1H, OH).

Scheme 16: Synthetic Procedure for the Preparation of Target Compound SM892.

[0260] ##STR00116##

[0261] N-(1-ethylpropyl)-2-[3-hydroxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide (SM892). To a solution of N-(1-ethylpropyl)-2-[3-methoxy-5,5-dioxido-9-(trifluoromethyl)-6H-dibenzo[c,e][1,2]thiazin-6-yl]acetamide 8a(Int-9) (0.23 g, 0.72 mmol) in dry CH.sub.2Cl.sub.2 (6 mL), 1M BBr.sub.3 in dry CH.sub.2Cl.sub.2 (2.16 mL, 2.16 mmol) was added dropwise at 0 C. and then, the reaction mixture was kept at 10 C. for 2 h. The mixture was poured into ice/water and extracted in EtOAc (3). The combined organic layers were washed with brine, dried over Na.sub.2SO.sub.4 and evaporated to dryness to give a white solid. After purification by flash column chromatography, eluting with CHCl.sub.3/MeOH (98:2), the title compound was obtained as a white solid in 35% yield: m.p. 216-218 C. .sup.1H NMR (400 MHz, CDCl.sub.3): 0.74 (t, J=7.2 Hz, 6H, CH.sub.32), 1.20-1.28 (m, 2H, CH.sub.2), 1.36-1.43 (m, 2H, CH.sub.2), 3.37-3.43 (m, 1H, CH), 4.62 (s, 2H, NCH.sub.2), 7.19-7.24 (m, 2H, ArH and CONH), 7.59 (d, J=8.4 Hz, 1H, ArH), 7.79 (d, J=7.5 Hz, 1H, ArH), 7.87 (d, J=8.6 Hz, 1H, ArH), 8.22 (d, J=8.8 Hz, 1H, ArH), 8.43 (s, 1H, ArH), 10.69 (s, 1H, OH).

Biology

Cells and Plasmids.

[0262] Cell lines used in this paper have been cultured in Dulbecco's Minimal Essential Medium (DMEM, Gibco, #11960-044), 10% heat-inactivated fetal bovine serum (A56-FBS), Penicillin/Streptomycin (Pen/Strep, Corning #20-002-C1), non-essential amino acids (NEAA, Gibco, #11140-035) and L-Glutamine (Gibco, #25030-024), unless specified differently. HEK293 cells were obtained from ATCC (ATCC CRL-1573). We used a subclone (A23) of HEK293 stably expressing a mouse WT, CR, or EGFP-tagged PrP. Cells were passaged in T25 flasks or 100 mm Petri dishes in media containing 200 g/ml of Hygromycin and split every 3-4 days. Cells have not been passaged more than 20 times from the original stock. Compounds used in the experiments were resuspended at 30 or 50 mM in DMSO, and diluted to make a 1000 stock solution, which was then used for serial dilutions. A 1 l aliquot of each compound dilution point was then added to cells plated in 1 mL of media with no selection antibiotics. Cloning strategies used to generate cDNAs encoding for WT, CR or EGFP-tagged PrP have been described previously.sup.20,31,32. The EGFP-PrP construct contains a monomerized version of EGFP inserted after codon 34 of mouse PrP. The identity of all constructs was confirmed by sequencing the entire coding region. All constructs were cloned into the pcDNA3.1(+)/hygro expression plasmid (Invitrogen). All plasmids were transfected using Lipofectamine 2000 (Life Technologies), following manufacturer's instructions.

Drug-Based Cell Assay (DBCA) and MTT Assay.

[0263] The DBCA was performed as described previously.sup.24, with minor modifications. Briefly, HEK293 cells expressing CR PrP were cultured at 60% confluence in 24-well plates on day 1. On day 2, cells were treated with 500 g/mL of Zeocinfor. Medium (containing fresh Zeocin and/or compound or vehicle) was replaced every 24 hr. On day 5, cell medium was removed and cells were incubated with 1 mg/mL of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT, Sigma Aldrich, St. Louis, MO) in PBS for 30 min at 37 C. MTT was carefully removed, and cells were re-suspended in 500 L of DMSO. Values for each well were obtained by measuring at 570 nm, using a plate spectrophotometer (Biotek).

Electrophysiology.

[0264] Field Excitatory Post-Synaptic Potential (EPSP) mouse hippocampal slices of 11 weeks old C57BL/6 mice was measured with a Multi Electrode Array (MEA) system. Slices were recorded for a 30 minutes baseline, LTP was then induced with a tetanic stimulation (3 trains, 500 MHz each) and recorded for additional 30 minutes. Prion synaptotoxicity was induced by incubating the slices for 5 minutes during the baseline with a 4% w/v lysate of MoRK13 cells chronically infected with M1000 prion strain. In order to evaluate the potential rescuing activity of SM884, the molecule was continuously perfused during the whole recording. The percentage of LTP was calculated considering the average EPSP amplitude of the last 10 minutes of recording, over the average EPSP amplitude of the last five minutes before the tetanic stimulation.

Immunofluorescence.

[0265] Cells expressing EGFP-PrP were plated on CellCarrier-384 Ultra microplates (Perkin Elmer) at a concentration of 12,000 cells/well and grown for approximately 24 h, to obtain a semi-confluent layer (60%). Vehicle (0.1% DMSO, volume equivalent) was used as a negative control. Cells were treated for 24 h and then fixed for 12 min at RT by adding methanol-free paraformaldehyde (Thermo Fisher Scientific) to a final concentration of 4%. Plates were then washed twice with PBS and counterstained with Hoechst 33342. The cell localization of EGFP-PrP was monitored using an Operetta High-Content Imaging System (Perkin Elmer). Imaging was performed in a widefield mode using a 20 High NA objective (0.75). Five fields were acquired in each well over two channels (380-445 Excitation-Emission for Hoechst and 475-525 for EGFP and Alexa 488). Image analysis was performed using the Harmony software version 4.1 (Perkin Elmer).

Western Blotting.

[0266] Samples were diluted 1:1 in 2 Laemli sample buffer (2% SDS, 10% glycerol, 100 mM Tris-HCl pH 6.8, 0.002% bromophenol blue, 100 mM DTT), heated at 95 C. for 10 min, then analyzed by SDS-PAGE. Proteins were electrophoretically transferred to polyvinylidene fluoride (PVDF) membranes, which were then blocked for 20 min in 5% (w/v) non-fat dry milk in Tris-buffered saline containing 0.05% Tween-20. After incubation with appropriate primary and secondary antibodies, signals were revealed using enhanced chemiluminescence (Luminata, BioRad), and visualized by a Bio-Rad XRS Chemidoc image scanner (Bio-Rad).

Preparation of Oligomers.

[0267] Synthetic A (1-42) peptide (Cat. Number KP2107, Karebay Biochem., Rochester, NY) was dissolved in hexafluoro-2-propanol, incubated for 10 min in a bath sonicator at maximum power, centrifuged at 15.000g for 1 min, aliquoted, dried, and stored at 80 C. Before use, the dried film was dissolved using DMSO and diluted to 100 M in F12 Medium (Invitrogen, Waltham, MA). Oligomers were obtained by incubating the peptide for 16 h at 25 C. This preparation routinely produces oligomers that elute near the void volume of a Superdex 75 10/300 size exclusion column (GE Healthcare, Little Chalfont, UK), and that react with oligomer-specific antibody A11. Final A oligomer concentrations were considered as monomer equivalents, since the size of the oligomers is heterogeneous.

Cultured Hippocampal Neurons.

[0268] Primary neuronal cultures were derived from the hippocampi of 2-day-old postnatal mice, and cultured as described previously.sup.11. Neurons were plated on 35-mm dishes (500,000 cells/dish) pre-coated with 25 g/mL poly-D-lysine (Sigma P6407) in B27/Neurobasal-A medium supplemented with 0.5 mM glutamine, 100 units/mL penicillin, and 100 g/mL streptomycin (all from Invitrogen). Experiments were performed 12 days after plating. Neurons were pre-treated for 20 min with each candidate compound or controls and then exposed for 20 mins or 3 hr to A oligomers (3 M). Triton-insoluble fractions (TIF) were analyzed by immunoblot with antibodies against phospho-SFK (Tyr 416) or Fyn. The phospho-SFK antibody detects pY416 in several SFKs, but previous studies showed that PrPC-dependent activation of kinases is specific for Fyn. Actin was used as loading control. Subcellular fractionation was performed as reported previously, with minor modifications. Neurons were homogenized using a Potter-Elvehjem homogenizer in 0.32 M ice-cold sucrose buffer (pH 7.4) containing 1 mM HEPES, 1 mM MgCl2, 10 mM NAF, 1 mM NaHCO.sub.3, and 0.1 mM PMSF in the presence of protease inhibitors (Complete mini, Roche Applied Science, Penzberg, Germany) and phosphatase inhibitors (PhosSTOP, Roche Applied Science). Samples were centrifuged at 13.000g for 15 min to obtain a crude membrane fraction. The pellet was re-suspended in buffer containing 150 mM KCl and 0.5% Triton X-100 and centrifuged at 100,000g for 1 hr. The final pellet, referred to as the Triton-insoluble fraction, was re-homogenized in 20 mM HEPES supplemented with protease and phosphatase inhibitors and then stored at 80 C. or directly used in further experiments. Protein concentration in each sample was quantified using the Bradford assay (Bio-Rad), and proteins (5 g) were then analyzed by Western blotting. Primary antibodies were as follow: anti-GluN2A and anti-GluN2B (both 1:2000; Invitrogen), anti-GluA1 and anti-GluA2 (both 1:1000; Millipore, Billerica, MA), anti-PSD-95 (post-synaptic density protein 95; 1:2000; Cayman Chemical, Ann Arbor, MI), and anti-actin (1:5000; Millipore). Western blots were analyzed by densitometry using Quantity One software (Bio-Rad). All experiments were repeated on at least 4 independent culture preparations (n4).

Production of Recombinant PrP.

[0269] RecHuPrP23-231 was expressed by competent E. coli Rosetta (DE3) bacteria harboring pOPIN E expression vector containing a wild type human Prnp construct (N-KKRPKPGGWNTGGSRYPGQGSPGGNRYPPQGGGGWGQPHGGGWGQPHGGGWG QPHGGGWGQPHGGGWGQGGGTHSQWNKPSKPKTNMKHMAGAAAAGAVVGGL GGYMLGSAMSRPIIHFGSDYEDRYYRENMIHRYPNQVYYRPMDEYSNQNNFVHDC VNITIKQHTVTTTTKGENFTETDVKMMERVVEQMCITQYERESQAYYQRGSS-C; SEQ ID No. 1). Bacteria from a glycerolate maintained at 80 C. were grown in a 250 ml Erlenmeyer flask containing 50 ml of LB broth overnight. The culture was then transferred to two 2 L Erlenmeyer flasks containing each 500 ml of minimal medium supplemented with 3 g/L glucose, 1 g/L NH4Cl, 1M MgSO4, 0.1 M CaCl.sub.2), 10 mg/mL thiamine and 10 mg/mL biotin. When the culture reached an OD600 of 0.9-1.2 AU, Isopropyl 3-D-1-thiogalactopyranoside (IPTG) was added to induce expression of PrP overnight under the same temperature and agitation conditions. Bacteria were then pelleted, lysed, inclusion bodies collected by centrifugation, and solubilized in 20 mM Tris-HCl, 0.5M NaCl, 6M Gnd/HCl, pH=8. Although the protein does not contain a His-tag, purification of the protein was performed with a histidine affinity column (HisTrap FF crude 5 ml, GE Healthcare Amersham) taking advantage of the natural His present in the octapeptide repeat region of PrP. After elution with buffer containing 20 mM Tris-HCl, 0.5M NaCl, 500 mM imidazole and 2 M guanidine-HCl, pH=8, the quality and purity of protein batches was assessed by BlueSafe (NZYTech, Lisbon) staining after electrophoresis in SDS-PAGE gels. The protein was folded to the PrPC conformation by dialysis against 20 mM sodium acetate buffer, pH=5. Aggregated material was removed by centrifugation. Correct folding was confirmed by CD and protein concentration, by measurement of absorbance at 280 nm. The protein was concentrated using Amicon centrifugal devices and the concentrated solution stored at 80 C. until used.

Dynamic Mass Redistribution.

[0270] The EnSight Multimode Plate Reader (Perkin Elmer, Waltham, MA) was used to carry out DMR analyses. Immobilization of full-length (residues 23-230), human recombinant PrPC (15 L/well of a 2.5 M PrPC solution in 10 mM sodium acetate buffer, pH 5) on label-free microplates (EnSpire-LFB high sensitivity microplates, Perkin Elmer) was obtained by amine-coupling chemistry. The interaction between each molecule, diluted to different concentrations in assay buffer (10 mM P04, pH 7.5, 2.4 mM KCl, 138 mM NaCl, 0.05% Tween-20) and PrPC, was monitored after a 30 min incubation at room temperature. All the steps were executed by employing a Zephyr Compact Liquid Handling Workstation (Perkin Elmer). The Kaleido software (Perkin Elmer) was used to acquire and process the data.

Statistical Analyses of Biological Data.

[0271] All the data were collected and analyzed blindly by two different operators. Statistical analyses, performed with the Prism software version 7.0 (GraphPad), included all the data points obtained, with the exception of experiments in which negative and/or positive controls did not give the expected outcome, which were discarded. No test for outliers was employed. The Kolmogorov-Smirnov normality test was applied (when possible, n5). Results were expressed as the meanstandard errors, unless specified. In some case, the dose-response experiments were fitted with a 4-parameter logistic (4PL) non-linear regression model, and fitting was estimated by calculating the R.sup.2. All the data were analyzed with the one-way ANOVA test, including an assessment of the normality of data, and corrected by the Dunnet post-hoc test. Probability (p) values <0.05 were considered as significant (*<0.05, **<0.01, ***<0.001).

In Vitro Bone Marrow-Derived Dendritic Cells

[0272] Bone marrow cells were isolated from C57BL/6 mice as previously describe (DOI: 10.1073/pnas.1619863114). BM was harvested from femur, tibia and pelvis using mortar and pestle in 1PBS supplemented with 0.5% BSA and 2 mM EDTA (MACS buffer), passed through a 70 m cell strainer and centrifuged at 1400 r.p.m for 5 minutes. Red blood cells were lysed with ACK lysis buffer (Ammonium Chloride 0.15 M, Potassium Carbonate 10 mM) and debris were removed by a gradient centrifugation using Histopaquel 119 (#11191, Sigma-Aldrich) prior to culture. Cells were resuspend at 2106 cells/ml in Iscove's Modified Dulbecco's Media (IMDM, #12440053, Thermo Fisher) supplemented with 0.1 Non-essential Amminoacids (#11140-035 Thermo Fisher), 1 mM Sodium Pyruvate (#11360-070, Thermo Fisher), 5 mM glutamine (#25030-024, Thermo Fisher), 50 M 2-Mercaptoethanol (#31350-010, Thermo Fisher), 100 U/ml penicillin, 100 g/ml streptomycin (#15140-122, Thermo Fisher) and 10% FBS (#10270-106, Thermo Fisher) (complete IMDM) containing 5% murine Flt3-L and were seed 5 ml/well in 6-plate tissue culture plates at 37 C. for 8-10 days. For all culture experiments, loosely adherent and suspension cells were harvested by gentle pipetting at the indicated time point.

[0273] cDC1 and cDC2 were sorted into complete IMDM were sorted by FACSAria Fusion as pDC B220+Bst2+, cDC1 B220-CD11c+MHC-II+CD24+CD172, cDC2 as B220-CD11c+MHCII+CD24-CD172+. Sort purity of >95% was confirmed by post-sort analysis before cells were used for further experiments.

Induction of EAE

[0274] All mice used were 12 weeks animals on the C57BL/6 background. EAE was induced with 200 g of myelin oligodendrocyte glycoprotein fragment MEVGWYRSPFSRVVHLYRNGK (SEQ ID No. 2; MOG35-55 peptide; #crb1000205n Cambridge Research Biochemicals) mixed with incomplete Freund's Adjuvant (#263910, BD) containing 4 mg/ml Mycobacterium tuberculosis TB H37 Ra (#231141 BD), at a ratio of 1:1 (v/v). Mice received 2 subcutaneous injections of 100 l each of the MOG/CFA mix. Mice then received a single intraperitoneal injection of pertussis toxin (#180, List Biological Laboratories) at a concentration of 1 ng/L in 200 L of PBS. Mice received a second injection of pertussis toxin at the same concentration two days after the initial EAE induction. Mice were orally treated with different doses of SM231 dissolved in 1PBS on alternating days starting at day 10 post-EAE induction. Mice were monitored and scored daily thereafter. EAE clinical scores were defined as follows: 0no signs, 1fully limp tail, 2hindlimb weakness, 3hindlimb paralysis, 4forelimb paralysis, 5moribund, as described previously (Mayo et al., 2014; Rothhammer et al., 2016). Sex differences were not analyzed but only a single sex was used within any set of EAE experiments. Mice were randomly assigned to treatment groups.

Results

[0275] Identification, characterization and optimization of SM3. Mutations in the central region of PrPC, including artificial deletions or disease-associated point mutations, induce a toxic ion channel activity that can be detected in transfected cells by patch-clamping techniques.sup.23,24. Cells expressing PrP mutants are also hypersensitive to several cationic drugs commonly used for selection of transfected cell lines, including aminoglycosides and phleomycin analogues.sup.20. The latter effect was used to establish a novel cellular assay for studying mutant PrPC-related toxicity, called the drug-based cell assay, or DBCA.sup.25. Importantly, co-expression of wild type (WT) PrPC suppresses both channel activity and citoxicity, likely indicating that mutant PrP forms aberrantly activate a signaling pathway normally regulated by PrPC. Thus, the DBCA represents a unique tool to identify compounds capable of modulating PrPC activity. We have developed an optimized and scaled-up format of the DBCA in 384-well plates, which was later employed to screen tens of thousands of small molecules.sup.21,22. Several compounds were found to suppress the toxicity of mutant PrP, with no detectable toxicity in WT cells. We focused efforts on one of these compounds (named SM3 [dibenzo [3,4][c,e]thiazine 5,5-dioxide], shown in FIG. 1A). SM3 possesses a drug-like chemical scaffold suitable for optimization and structure-activity relationship (SAR) experiments. Tens of derivatives (FIG. 1C) were designed and synthesized, and their biological activity tested by DBCA. Three chemical regions of the compound were explored, with the dual objective of improving potency and acquiring SAR information. Taking as reference the biological activity of the parent compound SM3 (FIG. 1i), we evaluated the activity of the different derivatives (FIG. 2). We made several important observations about SM3. Chemical modifications made at the spacer region were not fruitful. Conversely, substitutions at the C ring improved potency, with the 9-CF3 derivatives being the most potent. Branched substituents on the cyclohexyl group were not tolerated, whereas substituted phenyl rings generated analogues with potency comparable to the reference compound. Collectively, these results provided important SAR information about SM3, and directly suggested chemistry schemes to engineer additional derivatives and functionalized analogues. Moreover, we identified a potent derivative, called SM231, which showed activity by the DBCA in the sub-micromolar range (FIG. 3).

TABLE-US-00003 TABLE 3 Protective effect on HEK293 cells: the value is expressed as Rescue percent (% R.sub.MAX) produced by target compounds with respect to hit molecule SM3; IC.sub.50 and LD.sub.50 of target compounds derived from DBCA. [00117] LAC code X.sub.1 [00118] R.sub.1 R.sub.2 R.sub.2a R.sub.3 % R.sub.MAX.sup.1 IC.sub.50.sup.2 LD.sub.50.sup.3 SM3 H [00119] H H Br H 100 1.1 >100 SM7 H [00120] H H H H 55.93 SM8 H [00121] H H Br H 46.2 SM9 H [00122] H H Br H 45.18 SM10 H [00123] H H Br H 45.06 SM11 H [00124] H H Br H 43.87 SM225 H [00125] H H OMe H 61.53 SM226 H [00126] H H OH H 37.89 SM227 H [00127] Br H H H 41.15 SM228 H [00128] H Br H H 122.76 0.21 37.46 SM229 H [00129] H H H Br 120.78 0.25 28.21 SM230 H [00130] H H [00131] H 44.94 SM231 H [00132] H H CF.sub.3 H 139.52 0.14 22.4 SM338 H [00133] H CF.sub.3 H H 87.62 SM339 H [00134] H H H CF.sub.3 112.24 0.34 SM254 H [00135] H H Cl H 126.52 0.3 SM585 H [00136] H H H Cl 71.71 SM586 H [00137] H Cl H H 181.02 0.35 SM340 H [00138] H H SMe H 22.96 SM587 H [00139] H Cl H Cl 167.88 0.6 SM336 H [00140] H Cl F H 118.6 0.1 SM337 H [00141] H H F Cl 109.06 0.97 SM588 H [00142] H H CF.sub.3 H 10.56 SM589 H [00143] H H CF.sub.3 H 116.12 1.05 SM656 H [00144] H H CF.sub.3 H NS NS NS SM655 H [00145] H H CF.sub.3 H NS NS NS SM880 H [00146] H H CF.sub.3 H 78.26 SM881 F [00147] H H CF.sub.3 H 150.19 0.032 >100 SM882 F [00148] H H CF.sub.3 H 138.54 0.044 >100 SM883 OEt [00149] H H CF.sub.3 H 165.5 0.014 >100 SM884 F [00150] H H CF.sub.3 H 210.54 0.018 >100 SM885 F [00151] H H CF.sub.3 H 123.14 0.053 >100 SM879 [00152] 22.54 SM4 H [00153] H H Br H 66.56 SM5 H [00154] H H Br H 52.82 SM6 H [00155] H H Br H 48.1 SM162 H [00156] H H Br H 71.81 SM163 H [00157] H H Br H 104.28 SM164 H [00158] H H Br H 53.67 SM165 H [00159] H H Br H 65.56 SM166 H [00160] H H Br H 48.61 SM167 H [00161] H H Br H 56.63 SM168 H [00162] H H Br H 46.21 SM169 H [00163] H H Br H 59.15 SM170 H [00164] H H Br H 36.94 SM171 H [00165] H H Br H 101.77 SM172 H [00166] H H Br H 40.61 SM173 H [00167] H H Br H 66.03 SM174 H [00168] H H Br H 56.28 SM175 H [00169] H H Br H 66.2 SM176 H [00170] H H Br H 37.85 SM177 H [00171] H H Br H 58.41 SM178 H [00172] H H Br H 44.01 SM179 H [00173] H H Cl H 59.78 SM180 H [00174] H H i-Pr H 44.05 SM181 H [00175] H H Me H 59.35 SM219 H [00176] H H F H 53.97 SM220 H [00177] H H Br H 51.7 SM221 H [00178] H H Br H 44.87 SM222 H [00179] H H Br H 85.07 SM223 H [00180] H H Br H 54.69 SM224 H [00181] H H F H 71.5 SM886 H [00182] H H CF.sub.3 H NT SM887 H [00183] H H CF.sub.3 H ~50 SM888 F [00184] H H CF.sub.3 H ~50 SM889 F [00185] H H CF.sub.3 H ~50 SM890 OH [00186] H H CF.sub.3 H NT SM891 OH [00187] H H CF.sub.3 H NT SM892 OH [00188] H H CF.sub.3 H NT Notes: 1. R.sub.MAX indicates the maximum rescuing effect at the concentration of 1 M, expressed as percentage of the effect of SM3(LD24) at the same concentration. 2. Rescuing dose at 50%, expressed in M. This is typically obtained by testing a 8-point dose-response curve, performed only for compounds showing an improved activity (>110%) as compared to SM3(LD24). 3. Lethal dose at 50%, expressed in M. This is typically obtained by testing a 8-point dose-response curve, performed only for selected compounds. NS = not soluble, data obtained from these compounds are not reliable due to solubility issues NT = not tested

[0276] SM231 inhibits the synaptotoxic effects of A oligomers. Recent studies identified a role for PrPC into the toxicity of various misfolded oligomers of diseases-associated proteins, such as the amyloid B, whose accumulation underline the cognitive decline occurring in Alzheimer's disease.sup.2,4. The interaction between PrPC and A oligomers unleashes a rapid, toxic signaling pathway involving the metabotropic glutamate receptor 5 (mGluR5), activation of the tyrosine kinase Fyn, and phosphorylation of the NR2B subunit of NMDA receptor, ultimately producing dysregulation of receptor function, excitotoxicity and dendritic spine retraction.sup.12. In order to evaluate the effect of SM231 on A-induced activation of Fyn, we exposed primary hippocampal neurons to different concentrations of A oligomers for short times (10, 20 or 60 minutes). We confirmed that the oligomers induce a quick phosphorylation of the Fyn kinase (results at the 20 min time point are shown in FIG. 4). Consistent with previous observations.sup.26, this effect was prevented by treatment with a PrPC-directed compound [called Fe(III)-TMPyP].sup.35. Interestingly, co-incubation with SM231 completely abrogated A effects, restoring Fyn phosphorylation to normal levels (FIG. 4A). Next, we directly tested the ability of SM231 to block A oligomer-dependent synaptotoxicity. Primary hippocampal neurons were incubated for 3 hours with A oligomers (3 M). Consistent with previous reports.sup.11, we observed a decrease of several post-synaptic markers (subunits of NMDA receptor, GluN2A and GluN2B, and AMPA, GluA1 and GluA2, and the post-synaptic density protein 95, PSD-95), as evaluated by western blotting of the triton-insoluble fractions. These effects were rescued by treatment with anti-PrPC molecule Fe(III)-TMPyP. Importantly, co-incubation with SM231 for 20 minutes significantly rescued the levels of all the post-synaptic markers. The level of a control protein (actin) was not affected by either A oligomers or SM231. These data demonstrate that SM231 inhibits the ability of A oligomers to subvert the function of PrPC and activate a neurotoxic signaling pathway.

[0277] Chemical optimization of SM231 to more metabolically stable derivatives. Within the present invention it was carried-out a further chemical optimization cycle functionalizing positions predicted to positively improve the metabolic stability (FIG. 5). In particular, the C-3 position of the dibenzothiazine nucleus was functionalized by a F and an EtO (SM882 and SM883 derivatives, respectively) while in other three molecules the cyclohexyl was replaced by a more stable and hydrophilic groups (morpholine and tetrahydropyrane) or opened to give a branched chain (SM881, SM884, and SM885). Interestingly, when assayed on DBCA, compound SM884 resulted more potent than SM231 (FIG. 6), making these two molecules as promising lead compounds for further development.

[0278] SM884 rescues the synaptotoxic effects of prions in mouse brain slices. To test whether SM884 is able to inhibit prion-induced toxicity in a disease-relevant context, we turned to a recently developed ex vivo toxicity model.sup.27,28. This assay is based on mouse brain slices acutely exposed to either brain homogenates of terminally ill mice infected with lysates of cell lines chronically infected with the mouse-adapted M1000 human prion strain. We found that SM884 administration at a concentration of 0.1-0.03 M induces a significant (34% and 71%, respectively) rescue of long-term potentiation (LTP; FIG. 7). The higher potency detected at the lowest dose likely reflected an observed aggregation propensity of the molecule in the experimental conditions. These results were also fully consistent with the estimated half-maximal rescuing dose of the compound in cells (0.018 M), as evaluated by DBCA, and clearly showed that SM884 is capable of suppressing the synaptic impairment induced by prions in the low nanomolar concentration range.

[0279] Mouse DC1 and DC2 subsets express PrPC, and DC2 treated with SM231 promotes Treg cells expansion in DC-T cell co-cultures. Bone marrow derived dendritic cells were analyzed for expression of PrPC after stimulation with two different concentrations of SM231 or Fe(III)-TMPyP or vehicle. For this analysis, PrPC expression in each DC subsets was determined by western blot using specific anti-PrPC antibody. The authors of the present invention found that DC1 and DC2 expressed a baseline level of PrPC that slightly increases upon SM231 treatment, especially in DC2 (FIG. 8A). To assess the inhibitory function of DC1 or DC2 cells after treatment with SM231 or Fe(III)-TMPyP we performed in vitro co-cultures of DCs with nave CD4+ T cells. It was found that the priming ability of conventional DC2 was significantly affected by DC2 treatment with SM231. Specifically, these cells were able to favor the expansion of T cells expressing Treg cell markers FoxP3 and LAP and this effect required PrPC expression in DCs, since it was prevented in DC2 cells that were transfected by a specific PrPC siRNA but not by a control siRNA (FIG. 8B). Overall, these data suggest that PrPC stimulation may confer tolerogenic function to DC2, suppressing the default immunogenic program of this subset.

[0280] Compounds SM888 and SM889, like SM231, promote tolerogenic activity in cDC2. cDC2 cells have been reported to trans-present IL-6 indispensable for priming myelin peptide specific encephalitogenic pathogenic TH17 in a model of EAE. To assess whether additional derivates (i.e SM887, SM888, SM889) were able to induce regulatory functions in DCs subsets we performed in vitro co-cultures of cDC2 cells with nave ovalbumin (OVA)-specific transgenic CD4+ T cells in the presence of different concentrations of OVA. T cell proliferation was analyzed. We found that priming of cDC2 was significantly affected by cDC treatment with SM derivatives and more significantly by SM888 and SM889. Specifically, these cells were able to suppress antigen-specific CD4+ T cell proliferation and this effect was more pronounced when the molecules were used at the concentration of 10 uM (FIG. 9).

[0281] Administration SM231 ameliorates EAE and suppresses inflammatory cytokines in vivo. The authors of the invention investigated whether PrPC modulators could have a protective role in this experimental model. Groups of WT female C57BL/6 mice were immunized with the MOG35-55 peptide and injected intraperitoneally (i.p.) with Fe(III)-TMPyP or SM231 at two doses every other day from day 3 until day 24 after vaccination. Control mice received vehicle alone. EAE clinical scores were recorded daily over this timeframe (FIG. 10A). We found that SM231 (FIG. 10B) administration resulted in a reduced disease as compared to control mice (P<0.05). At d 25 post-vaccination, white matter demyelination and inflammatory infiltrates were reduced by SM231 compared to vehicle treated control (FIG. 10C). Moreover, SM231 in vivo treatment resulted in a reduced secretion of inflammatory cytokines such as IL-17A and GM-CSF by CD4+ T cells purified from cervical lymph nodes and re-stimulated with MOG in vitro. These data support the therapeutic and also physiologic value of PrPC activation in the control of neuroinflammation. Moreover, these data suggest that molecules such as SM231 may exert these effects by regulating potential inflammatory antigen presenting cells also in vivo. Importantly, these data were similar to those obtained with other derivatives of SM231.

[0282] SM231 does not act by directly targeting PrPC. In light of the promising ability of SM compounds to modulate the activity of PrPC in several experimental contexts, the hypothesis that these molecules act by directly targeting the protein was tested. First, it was hypothesized that the compound may promote the re-localization of PrPC from the cell surface, a mode of action recently observed for an anti-prion phenothiazine derivative (chlorpromazine, CPZ).sup.29,30. HEK293 cells stably expressing an EGFP-tagged version of PrPC were treated with different concentration of SM231, CPZ or vehicle control, and PrPC localization at the cell surface was monitored by imaging techniques (FIG. 11A). Results showed that CPZ induced a dose-dependent relocalization of EGPF-PrPC from the cell surface to intracellular compartments, in line with previous data.sup.30. Conversely, no changes were detected for SM231, suggesting that this compound does not exert its effects by inducing the relocalization of PrPC from the cell surface. Next, it was tested whether SM231 could alter PrPC expression. HEK293 cells stably expressing wild-type PrPC were treated with SM231 at different concentrations. Total PrPC levels were then evaluated in whole-cell lysates by western blotting (FIG. 11B). Once again, no difference in PrPC expression was found upon treatment with SM231. Finally, the direct binding of SM231 to recombinant PrPC was tested by dynamic mass redistribution (DMR), a biophysical technique previously employed to detect the interaction of small molecules to PrPC.sup.26. Fe(III)-TMPyP and chlorpromazine (CPZ), two compounds previously reported to show respectively high and low affinity for PrPC.sup.19,30 were used as control. However, no interaction was observed between SM231 and recombinant PrPC, even at the highest concentration (1 mM, FIG. 11C). Collectively, these results indicate that SM231 does not act by directly binding PrPC, or by altering its expression or localization.

[0283] An FXR-inhibitor suppresses mutant PrP cytotoxicity. The two FXR agonists, WAY-362450 and Fexaramine, whose structure is reported below, were tested using the DBCA assay.

##STR00189##

[0284] HEK293 cells expressing CR PrP were cultured at 60% confluence in 24-well plates on day 1. On day 2, cells were treated with 500 g/mL of Zeocin and/or individual FXR agonists at different concentrations (0.03-30 M) for 72 hr. Medium (containing fresh Zeocin and/or FXR agonists) was replaced every 24 hr. On day 5, cell medium was removed and cells were incubated with 1 mg/mL of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) in PBS for 30 min at 37 C. to evaluate cell viability. Interestingly, the FXR agonist WAY-362450 rescued CR PrP-dependent citotoxicity in a dose-dependent fashion, with an inhibitory concentration at 50% (IC.sub.50) value in the sub-micromolar range (FIG. 12). Importantly, the FXR agonist Fexaramine showed a much lower effect, possibly reflecting a different activity of the two agonists against specific FXR isoforms and/or recruiting also different coactivators. Collectively, these results establish a direct pharmacological connection between mutant PrP toxicity and the activity of the FXR receptor, and suggest that this receptor could be the target of SM compounds.

[0285] SM231 mediates FXR gene transcriptional activity in murine hepatocytes. Mouse primary hepatocytes were isolated from 6-8-week-old C57Bl6/J wild-type male mice (from Charles River). 310.sup.6 prymary hepatocytes were stimulated with increasing concentrations of SM231 or WAY-362450, a potent and selective Farnesoid X receptor (FXR) agonist for 4 or 12 hours. The expression of FXR (nr1 h4) and the FXR target gene Nr0b2, was evaluated by RT-qPCR using specific primers.

[0286] In this experiment, similarly to the reference agonist WAY-362450, SM231 promoted significant FXR transcriptional activity in these cells, specifically three hours after treatment (FIG. 13). The effects were lost after 6 hours of activation for both molecules. These data suggest that SM231 may act in cells as an FXR receptor agonist.

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