ANNULATED GLYCOSIDASE INHIBITORS

Abstract

Compounds of formula (I), wherein A, R, W.sup.1, W.sup.2, W.sup.3, W.sup.4, W.sup.5, W.sup.6, L, Q, R.sup.x and u have the meaning according to the claims, can be employed, inter alia, for the treatment of tauopathies and Alzheimer's disease.

##STR00001##

Claims

1. A compound of formula (I) ##STR00314## wherein R is straight chain or branched alkyl having 1 to 6 carbon atoms, wherein 1 to 5 hydrogen atoms may be replaced by Hal or OH; W.sup.1, W.sup.2 denote each independently C, CH, N; W.sup.3, W.sup.4 and W.sup.5 denote each independently C, CH, N, CH.sub.2, NH, S, O, SO, SO.sub.2, S(O)(NR.sup.3), N(SO)R.sup.3, CO; ##STR00315## W.sup.6 denotes CH, N, CH.sub.2, NH, S, O, SO, SO.sub.2, S(O)(NR.sup.3), CO or W.sup.6 is absent; L is a single bond or one of the following groups: O, NR.sup.3, CH.sub.2, OCH.sub.2, CH.sub.2CH.sub.2, CONR.sup.3, CONR.sup.3CH.sub.2, NR.sup.3CO, NR.sup.3COCH.sub.2; A denotes one of the following groups: ##STR00316## X is N or CR; Y is O, S, SO or SO.sub.2; R, R denote each independently H, Hal or straight chain or branched alkyl having 1 to 12 carbon atoms; R, R independently denote H, Hal, NR.sup.3R.sup.4, CHR.sup.3R.sup.4, OR.sup.3, CN or a straight chain or branched alkyl having 1 to 12 carbon atoms, wherein 1 to 3 CH.sub.2-groups may be replaced by a group selected from O, NR.sup.3, S, SO, SO.sub.2, S(O)(NR.sup.3), N(SO)R.sup.3, CO, COO, OCO, CONR.sup.3, NR.sup.3CO, ##STR00317## and wherein 1 to 5 hydrogen atoms may be replaced by Hal, NR.sup.3R.sup.4 or NO.sub.2 or by one of the following groups: ##STR00318## or R, R independently denote one of the following groups: ##STR00319## R.sup.3, R.sup.4 denote each independently H or a straight chain or branched alkyl group having 1 to 12 carbon atoms; Q is absent or the group Q(R.sup.X).sub.u denotes one of the following groups: ##STR00320## ##STR00321## Z.sup.1 is S, O, NR.sup.3; Z.sup.2, Z.sup.3 independently denote CR.sup.5 or N; Z.sup.4 is N, CH, CON, COCH; Z.sup.5 is O, NR.sup.8, CHR.sup.5, SO.sub.2, S(O)(NR.sup.3), N(SO)R.sup.3, ##STR00322## Z.sup.6 is CH.sub.2, CO, S(O)(NR.sup.3), N(SO)R.sup.3, ##STR00323## Z.sup.7 is C(R.sup.3).sub.2, S, O, NR.sup.3; s denotes 0 or 1; T is N, CH or CR.sup.7; R.sup.3 denotes H or a straight chain or branched alkyl group having 1 to 12 carbon atoms, wherein 1 to 3 CH.sub.2-groups may be replaced by a group selected from SO.sub.2, CO, O and wherein 1 to 5 hydrogen atoms may be replaced by Hal; R.sup.x, R.sup.5, R.sup.6, R.sup.7 independently denote H, Hal, CN, NR.sup.3R.sup.4, NO.sub.2 or a straight chain or branched alkyl having 1 to 12 carbon atoms, wherein 1 to 3 CH.sub.2-groups may be replaced by a group selected from O, NR.sup.3, S, SO, SO.sub.2, S(O)(NR.sup.3), N(SO)R.sup.3, CO, COO, OCO, CONR.sup.3, NR.sup.3CO ##STR00324## and wherein 1 to 5 hydrogen atoms may be replaced by Hal, NR.sup.3R.sup.4, NO.sub.2, OR.sup.3, Het, Ar, Cyc or by one of the following groups: ##STR00325## or R.sup.x, R.sup.5, R.sup.6, R.sup.7 denote Ar, Het or Cyc or one of the following groups: ##STR00326## R.sup.8 denotes H or straight chain or branched alkyl having 1 to 12 carbon atoms, wherein 1 to 3 CH.sub.2-groups may be replaced by a group selected from SO, SO.sub.2, S(O)(NR.sup.3), N(SO)R.sup.3, CO, COO, OCO, CONR.sup.3, NR.sup.3CO, and ##STR00327## and further wherein 1 to 5 hydrogen atoms may be replaced by CN, OR.sup.3, SR.sup.3, Hal, NR.sup.3R.sup.4, NO.sub.2 or by one of the following groups: ##STR00328## or R.sup.8 denote one of the following groups: ##STR00329## Hal denotes F, Cl, Br or I; Het denotes a saturated, unsaturated or aromatic ring, being monocyclic or bicyclic or fused-bicyclic and having 3- to 8-members and containing 1 to 4 heteroatoms selected from N, O and S, which may be substituted by 1 to 3 substituents selected from R.sup.5, Hal and OR.sup.3; Ar denotes a 6-membered carbocyclic aromatic ring or a fused or non-fused bicylic aromatic ring system, which is optionally substituted by 1 to 3 substituents independently selected from R.sup.5, OR.sup.3 and Hal; Cyc denotes a saturated or an unsaturated carbocyclic ring having from 3 to 8 carbon atoms which is optionally substituted by 1 to 3 substituents independently selected from R.sup.5 or Hal or OH; t and q denote independently from one another 0, 1, 2 or 3, with t+q1 u denotes 1 or 2, and pharmaceutically usable derivatives, solvates, salts, prodrugs, tautomers, enantiomers, racemates and stereoisomers thereof, including mixtures thereof in all ratios and compounds of formula I, wherein one or more H atoms are replaced by D (deuterium).

2. A compound chosen from the group consisting of formula Ia and Ib: ##STR00330## wherein A, R, L, R.sup.x, W.sup.1, W.sup.2 W.sup.3, W.sup.4, W.sup.5, W.sup.6, u and Q have the meaning given in claim 1.

3. A mixture comprising compounds Ia and Ib according to claim 2, having identical groups A, R, L, R.sup.x, W.sup.1, W.sup.2W.sup.3, W.sup.4, W.sup.5, W.sup.6, u and Q in equal or unequal amounts.

4. A compound of formula I according to claim 1, wherein R is methyl.

5. A compound of formula I according to claim 1, wherein A denotes one of the following groups: ##STR00331## wherein R and R have the meaning given in claim 1.

6. A compound of formula I according to claim 1, wherein the group Q-(R.sup.x).sub.u denotes H or one of the following groups: ##STR00332## ##STR00333## wherein T, Z.sup.5, Z.sup.6, R.sup.6 and R.sup.7 have the meaning given in claim 1.

7. A compound of formula I according to claim 1 to claim 6, wherein R.sup.x, R.sup.5, R.sup.6, R.sup.7 are independently selected from H, CN, SO.sub.2CH.sub.3, SO.sub.2CH.sub.2CH.sub.3, SO.sub.2CH.sub.2CH.sub.2OH, SO.sub.2CH.sub.2CH.sub.2OCH.sub.3, S(O)(NR.sup.3)CH.sub.3, S(O)(NR.sup.3)CH.sub.2CH.sub.3, S(O)(NR.sup.3)CH.sub.2CH.sub.2OH, S(O)(NR.sup.3)CH.sub.2CH.sub.2OCH.sub.3, N(SO)R.sup.3CH.sub.3, N(SO)R.sup.3CH.sub.2CH.sub.3, N(SO)R.sup.3CH.sub.2CH.sub.2OH, N(SO)R.sup.3CH.sub.2CH.sub.2OCH.sub.3, Hal, NR.sup.3R.sup.4, NO.sub.2, phenyl, benzyl, CH.sub.2-pyridyl, O-phenyl, O-pyridyl, O-pyrimidinyl, O-benzyl, 2-, 3- or 4-hydroxy or methoxyphenyl, alkyl, alkoxy (Oalkyl), hydroxyalkylen, alkoxyalkylen, COOH, COOalkyl, CONHalkyl, CONH.sub.2, CON(CH.sub.3).sub.2, NHCOalkyl, NHCOCH.sub.3, NHCOphenyl, NHCOpyridyl, NHCH.sub.2CH.sub.3, NHCH.sub.2CH.sub.2CH.sub.3, NHCOCH.sub.2CH.sub.2OH, CON-morpholinyl, CON(CH.sub.3)CH.sub.2CH.sub.2N(CH.sub.3).sub.2, CO-1-piperidinyl, CO-4-hydroxy-1-piperidinyl, CO-1-piperazinyl, CO-4-methyl-1-piperazinyl, CH.sub.2N-morpholinyl, CH.sub.2N(H)COCH.sub.3, CH.sub.2N(CH.sub.3)COCH.sub.3, CH.sub.2NH.sub.2, NH.sub.2, CH(OH)CH.sub.3, CH(OR.sup.3)CH.sub.3 and a group ##STR00334## wherein t+q is 2 or 3 and Z.sup.7 and R.sup.3 and R.sup.3 and R.sup.4 have the meaning given in claim 1.

8. A compound of formula I according to claim 1 to claim 7, wherein L is a single bond.

9. A compound of formula I according to any one of claim 1 to claim 8, wherein u denotes 1.

10. A compound according to claim 1, selected from the following group: TABLE-US-00005 Example No Structure Chirality 1 embedded image Racemic 2 Racemic 3 Racemic 4 Racennic 5 Racemic 6 Racemic 7 Racemic 8 Racemic 9 Racemic 10 Racemic 11 Racemic 12 Chiral SFC, Method A, First eluting compound 13 Chiral SFC, Method A, Second eluting compound 14 Racemic 15a Racemic 15b Racemic 16a Racemic 16b Racemic 17 embedded image Racemic 18 Racemic 19 Racemic 20 Racemic 21 Racemic 22 Racemic 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 embedded image 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 embedded image 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 and/or and pharmaceutically usable derivatives, solvates, salts, tautomers, enantiomers, racemates and stereoisomers thereof, including mixtures thereof in all ratios.

11. A compound of formula (I) according to any one of claims 1 to 10 for use as a medicament.

12. A compound of formula (I) according to any one of claims 1 to 10 and pharmaceutically usable derivatives, solvates, salts, tautomers, enantiomers, racemates and stereoisomers thereof, including mixtures thereof in all ratios for use in a treatment of a condition selected from neurodegenerative diseases, diabetes, cancer, cardiovascular diseases and stroke.

13. A compound for use in a treatment of a condition according to claim 12, wherein the condition is selected from the group of one or more tauopathies and Alzheimer's disease, Dementia, Amyotrophic lateral sclerosis (ALS), Amyotrophic lateral sclerosis with cognitive impairment (ALSci), Argyrophilic grain disease, Behavioural variant frontomeporal dmenetia (BvFTD), Bluit disease, Chronic traumatic encephalopathy, Corticobasal degeneration (CBP), Dementia pugilistica, Diffuse neurofibrillary tangles with calcification, Down's syndrome, Familial British dementia, Familial Danish dementia, Frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), Frontotemporal lobar degeneration (FTLD), Ganglioglioma, Gangliocytoma, Gerstmann-Straussler-Scheinker disease, Globular glia tauopathy, Guadeloupean parkinsonism, Hallevorden-Spatz disease (neurodegeneration with brain iron accumulation type 1), Lead encephalopathy, Lipofuscinosis, Meningioangiomatosis, Multiple system atrophy, Myotonic dystrophy, Niemann-Pick disease (type C), Pallido-ponto-nigral degeneration, Parkinsonism-dementia complex of Guam, Pick's disease (PiD), Parkinson's disease dementia, Postencephalitic parkinsonism (PEP), Primary progressive aphasia, Prion diseases (including Creutzfeldt-Jakob Disease (GJD), Progressive nonfluent aphasia, Variant Creutzfeldt-Jakob Disease (vCJD), Fatal Familial Insomnia, Kuru, Progressive supercortical gliosis, Progressive supranuclear palsy (PSP), Semantic dementia, Steele-Richardson-Olszewski syndrome, Subacute sclerosing panencephalitis, Tangle-only dementia, Tuberous sclerosis, Huntington's disease and Parkinson's disease, preferably one or more tauopathies and Alzheimer's disease.

14. A method for treating a tauopathy, wherein a compound defined in any one of claims 1 to 10 is administered to a mammal in need of such treatment.

15. A method for inhibiting a glycosidase, wherein a system expressing the glycosidase is contacted with a compound as defined in any one of claims 1 to 10 under in-vitro conditions such that the glycosidase is inhibited.

16. A pharmaceutical composition comprising as active ingredient a compound according to any one of claims 1 to 10 together with pharmaceutically tolerable adjuvants and/or excipients, optionally in combination with one or more further active ingredients.

Description

EXPERIMENTAL PART

[0207] The compounds according to Formula (I) can be prepared from readily available starting materials by several synthetic approaches, using both solution-phase and solid-phase chemistry protocols or mixed solution and solid phase protocols. Examples of synthetic pathways are described below in the examples. All reported yields are non optimized yields. Unless otherwise stated, compounds of Formula (I) and related formulae obtained as a racemic mixture can be separated to provide an enantiomerically enriched mixture or a pure enantiomer.

[0208] The commercially available starting materials used in the following experimental description were purchased from Aldrich, Sigma, ACROS, ABCR, Combi-Blocks, Matrix, Apollo scientific, Alfa Aesar, etc. unless otherwise reported.

[0209] The HPLC, MS and NMR data provided in the examples described below are obtained as followed:

[0210] .sup.1H NMR analyses were carried out using BRUKER NMR, model AV-II and AV-III 400 MHz FT-NMR. Residual signal of deuterated solvent was used as internal reference. Chemical shifts () are reported in ppm in relative to the residual solvent signal (=2.50 for .sup.1H NMR in DMSO-d.sub.6, and 7.26 in CDCl.sub.3). s (singlet), d (doublet), t (triplet), q (quadruplet), br (broad), quint (quintuplet).

LCMS Analysis Condition:

[0211] Instrument name: Agilent Technologies 1290 infinity 11.

[0212] Method A: Method: A-0.1% TFA in H.sub.2O, B-0.1% TFA in MeCN; flow rate: 2.0 mL/min; column: XBridge C8 (504.6 mm, 3.5 m), +ve mode

[0213] Method B: Method: A-10 mM NH.sub.4HCO.sub.3 in H.sub.2O, B-MeCN; flow rate: 1.0 mL/min; column: XBridge C8 (504.6 mm, 3.5 m), +ve mode

HPLC Analysis Condition:

[0214] Instrument name: Agilent 1200 Series instruments as followed using % with UV detection (maxplot).

[0215] Method A: Method: A-0.1% TFA in H.sub.2O, B-0.1% TFA in MeCN; flow rate: 2.0 mL/min; column: XBridge C8 (504.6 mm, 3.5 m).

[0216] Method B: Method: A-10 mM NH.sub.4HCO.sub.3 in H.sub.2O, B-MeCN; flow rate: 1.0 mL/min; column: XBridge C8 (504.6 mm, 3.5 m).

Chiral SFC Analysis Condition:

[0217] Instrument name: THAR-SFC 80 and THAR-SFC 200 (analytical) Ratio between CO.sub.2 and co-solvent is ranging between 50:50 and 90:10

[0218] Method A: Co-solvent: 20 mM ammonia in IPA; flow: 4 mL/min; column: Lux A1 (2504.6 mm, 5 m).

Prep-HPLC Analysis Condition:

[0219] Method A: A-0.1% TFA in H.sub.2O, B-MeOH or MeCN; column: Sunfire C8 (19250 mm, 5 m) or Sunfire C18 (30250 mm, 10 m).

[0220] Method B: A-10 mM NH.sub.4HCO.sub.3 in H.sub.2O, B-MeOH or MeCN, Column: Sunfire C8 (19250 mm, 5 m) or Sunfire C18 (30250 mm, 10 m).

MD Auto-Prep Condition:

[0221] The mass directed preparative HPLC purifications were performed with a mass directed autopurification Fractionlynx from Waters.

[0222] Method A: 0.1% TFA in H.sub.2O, B-MeOH or MeCN, Column: Symmetry C8 (30019 mm, 7 m).

Chiral Preparative SFC Analysis Condition:

[0223] Instrument name: THAR-SFC 80, THAR-SFC 200 and Pic SFC 10-150 Ratio between CO.sub.2 and co-solvent is ranging between 50:50 and 90:10

[0224] Method A: Co-solvent: 20 mM Ammonia in IPA FLOW: 5 mL/min; COLUMN: Lux A1 (25030) mm, 5 m

[0225] Method B: Co-solvent: 20 mM MeOH FLOW: 5 mL/min; COLUMN: Lux A1 (25030) mm, 5 m

[0226] The microwave chemistry was performed on a single mode microwave reactor Initiator Sixty from Biotage.

[0227] General flash chromatography conditions used for the purification of intermediates or compounds of Formula I: silica gel 230-400 mesh; gradients used as eluent: 10 to 80% EtOAc in petroleum ether or 1 to 15% MeOH in DCM

Intermediate 1: 5-(1-Chloroethyl)benzo[d][1,3]dioxole

[0228] ##STR00221##

Step 1: 1-(Benzo[d][1,3]dioxol-5-yl)ethan-1-ol

[0229] ##STR00222##

[0230] To a stirred solution of 3,4-methylenedioxy acetophenone (50.0 g, 0.31 mol, Alfa aesar) in dry methanol (1000 mL), NaBH.sub.4 (13.83 g, 0.37 mol, Loba chemie) was added slowly at 0 C. and the reaction mixture was stirred at RT for 1 h. Completion of the reaction was monitored by TLC, then the reaction mixture was concentrated under vacuum. The resulting material was dissolved in EtOAc, the organic layer was washed with water (100 mL), brine solution (100 mL) and dried over anhydrous Na.sub.2SO.sub.4. The organic layer was evaporated under vacuum and the resulting crude material was forwarded to the next step without any further purification. Yield: 98% (50.0 g, colorless liquid). .sup.1H NMR (400 MHz, CDCl.sub.3): 6.89 (s, 1H), 6.89-6.75 (m, 2H), 5.95 (s, 2H), 4.81 (t, J=8.0 Hz, 1H), 1.46 (d, J=8.0 Hz, 3H). LCMS: (Method B) 149.0 (MH.sub.2O+H); Rt. 2.5 min, 98.6% (Max). HPLC: (Method A) RT 2.4 min, 99.5% (Max).

Step 2: 5-(1-Chloroethyl)benzo[d][1,3]dioxole

[0231] ##STR00223##

[0232] To a stirred solution of 1-(benzo[d][1,3]dioxol-5-yl)ethan-1-ol (50.0 g, 0.3 mol) in DCM (400 mL), thionyl chloride was added slowly at 0 C. and continued at RT for 2 h. After completion of the reaction, the reaction mixture was concentrated under vacuum and co-distilled with DCM (100 mL). The resulting crude material was forwarded to the next step as such without further purification. Yield: 64% (35.0 g, brown liquid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.06 (d, J=4.0 Hz, 1H), 6.93 (d, J=8.0 Hz. 1H), 6.86 (d, J=8.0 Hz, 1H), 6.01 (s, 2H), 2.49 (q, J=8.9 Hz, 1H), 1.74 (d, J=8.9 Hz, 3H). LCMS: (Method B) 149.0 (MCl+H); Rt. 3.7 min, 80.2% (Max).

Intermediate 2: 6-(1-chloroethyl)-2,3-dihydrobenzofuran

[0233] ##STR00224##

Step 1: 2-(2,5-dibromophenoxy)ethan-1-ol

[0234] ##STR00225##

[0235] To a stirred solution of 1,4-dibromo-2-fluorobenzene (Combi-Blocks, 1000 g, 3.94 mol) in ethylene glycol (5100 mL), NMP (500 mL) was added at RT under nitrogen atmosphere. Then KO.sup.tBu (1547 g, 1.38 mol) was added in portions over 45 min at 5 C. and the resulting mixture was heated at 90 C. for 16 h. Completion of the reaction was monitored by HPLC (Method A), the reaction mixture was then cooled to RT, diluted with water (2000 mL) and stirred for 15 min. The resulting solid was filtered and washed with ethylene glycol (2300 mL). Water (16000 mL) was added to the filtrate, cooled to 10 C. and stirred for 1 h at the same temperature to precipitate out the whole solid. The obtained solid was filtered and washed with water (21000 mL), pet ether (31000 mL) and dried under vacuum. This solid was co-distilled with toluene (3500 mL) to afford the title compound. Yield: 78% (910 g, white solid). .sup.1H NMR (400 MHz, CDCl.sub.3): 7.41 (d, J=8.0 Hz, 1H), 7.06-7.00 (m, 2H), 4.14 (t, J=4.0 Hz, 2H), 4.01 (q, J=3.6 Hz, 2H). LCMS: (Method A) 296.0 (M+H), Rt. 3.9 min, 98.2% (Max). HPLC: (Method A) Rt. 3.7 min, 99.5% (Max).

Step 2: 1,4-dibromo-2-(2-bromoethoxy)benzene

[0236] ##STR00226##

[0237] To a stirred solution of 2-(2,5-dibromophenoxy)ethan-1-ol (910.0 g, 3.07 mol) in toluene (6370 mL), PBr.sub.3 (Aldrich, 145 mL, 1.54 mol) was added under nitrogen atmosphere at 0 C. over 15 min. The resulting mixture was heated at 90 C. for 4 h and then cooled to 0 C. PBr.sub.3 (13.57 mL, 142.92 mmol) was added followed by the slow addition of water (20 mL) and heating was continued at 90 C. for 3 h. Completion of the reaction was monitored by TLC, the reaction mixture was then cooled to 10 C. and quenched with 1N NaOH solution (2200 mL). The milky solid layer, formed immediately after quenching, was filtered through celite pad. The organic layer was separated, washed with water (1820 mL), brine solution (1820 mL) and dried over anhydrous Na.sub.2SO.sub.4. It was then evaporated at 45 C. under vacuum. The resulting crude material was dissolved in EtOAc (3185 mL), the organic layer was washed with water (1820 mL), brine solution (1820 mL) and dried over anhydrous Na.sub.2SO.sub.4. The organic layer was evaporated at 40 C. under reduced pressure to afford the title compound. Yield: 86% (946 g, white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.54 (d, J=8.4 Hz, 1H), 7.36 (d, J=1.6 Hz, 1H), 7.13-7.10 (m, 1H), 4.45 (t, J=1.2 Hz, 2H), 3.82 (t, J=1.6 Hz, 2H). HPLC: (Method A) Rt. 4.7 min, 93.0% (Max).

Step 3: 2,3-dihydrobenzofuran-6-carbaldehyde

[0238] ##STR00227##

[0239] To a stirred solution of 1,4-dibromo-2-(2-bromoethoxy)benzene (946 g, 2.64 mol) in dry THF (9.5 L) under nitrogen atmosphere, n-butyl lithium (1812 mL, 2.89 mol, 1.6 M in hexane) was added slowly over 30 min at 78 C. and continued for 1 h at the same temperature. A second batch of n-butyl lithium (1812 mL, 2.89 mol, 1.6 M in hexane) was added slowly over 30 min at 78 C. and stirring was continued for another 1 h. Then DMF (408 mL, 5.27 mol) was added slowly at same temperature and the mixture was stirred for 45 min. After completion of the reaction (monitored by TLC), the reaction mixture was warmed to 10 C., quenched with the addition of sat.NH.sub.4Cl solution (3784 mL) and the aqueous layer was extracted with EtOAc (22800 mL). The combined organic layer was washed with water (2838 mL), brine solution (2838 mL), dried over anhydrous Na.sub.2SO.sub.4 and evaporated at 40 C. under reduced pressure to afford the title compound. Yield: 96% crude (404 g, pale brown gummy solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.90 (s, 1H), 7.45 (dd, J=5.2, 1.2 Hz, 2H), 7.19 (s, 1H), 4.60 (t, J=8.7 Hz, 2H), 3.27 (t, J=8.7 Hz, 2H). HPLC: (Method A) Rt. 2.9 min, 84.3% (Max).

Step 4: 1-(2,3-dihydrobenzofuran-6-yl)ethan-1-ol

[0240] ##STR00228##

[0241] To a stirred solution of 2,3-dihydrobenzofuran-6-carbaldehyde (404 g, 2.73 mol) in dry THF (4040 mL) under nitrogen atmosphere, methyl magnesium chloride solution (1820 mL, 5.45 mol, 3 M in THF) was added slowly over 30 min at 0 C. and stirred for 2 h at RT. Completion of the reaction was monitored by TLC, the reaction mixture was then quenched by using sat. NH.sub.4Cl solution (1616 mL) and extracted with EtOAc (22828 mL). The combined organic layer was washed with water (1616 mL), brine solution (1616 mL), dried over Na.sub.2SO.sub.4 and evaporated at 45 C. under reduced pressure. The resulting crude material was purified by flash chromatography (Silica gel: 60-120 mesh, eluent: 18% EtOAc in pet ether) to afford the title compound. Yield: 46% (210 g, pale brown gummy solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.12 (d, J=7.2 Hz, 1H), 6.77 (dd, J=7.6, 0.8 Hz, 1H), 6.72 (s, 1H), 5.05 (d, J=4.4 Hz, 1H), 4.66-4.60 (m, 1H), 4.48 (t, J=8.4 Hz, 2H), 3.12 (t, J=8.4 Hz, 2H), 1.28 (t, J=6.8 Hz, 3H). LCMS: (Method A) 147.0 (M+H) (alkene), Rt. 2.7 min, 90.7% (Max). HPLC: (Method A) Rt. 2.6 min, 91.7% (Max).

Step 5: 6-(1-chloroethyl)-2,3-dihydrobenzofuran

[0242] ##STR00229##

[0243] To a stirred solution of 1-(2,3-dihydrobenzofuran-6-yl)ethan-1-ol (200 g, 1.22 mmol) in DCM (1600 mL) at 0 C., oxalyl chloride (155 mL, 3.66 mmol) and catalytic amount of DMF (2 mL) were added and the reaction mixture was stirred at RT for 16 h. Then the reaction mixture was concentrated under vacuum and co-distilled with dry DCM (3500 mL) to afford the title compound. Yield: 97% (crude) (220 g, pale brown gummy solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.32 (d, J=7.6 Hz, 1H), 6.92 (d, J=9.6 Hz, 2H), 5.28 (q, J=13.2 Hz, 1H), 4.52 (t, J=8.4 Hz, 2H), 3.15 (t, J=8.8 Hz, 2H), 1.75 (d, J=8.4 Hz, 3H). LCMS: (Method A) 147.2 (M+H-Chloro), Rt. 4.2 min, 77.2% (Max).

[0244] Intermediate 3: tert-butyl (E)-3-((dimethylamino)methylene)-4-oxopiperidine-1-carboxylate

##STR00230##

[0245] To a stirred solution of tert-butyl 4-oxopiperidine-1-carboxylate (10 g, 50.18 mmol), DMF-DMA (73.5 mL, 552 mmol) was added and the reaction mixture was heated at 105 C. for 1 h. Completion of the reaction was monitored by TLC, then the reaction mixture was evaporated under vacuum. The resulting crude material was purified by flash chromatograpy (Biotage Isolera, eluent: 20-30% EtOAc in hexane) to afford the title compound. Yield: 24% (3 g, brown gummy solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.30 (s, 1H), 4.46 (s, 2H), 3.47 (t, J=8.0 Hz, 2H), 3.06 (s, 6H), 2.26 (t, J=8.8 Hz, 2H), 1.42 (s, 9H). LCMS: (Method B) 255.0 (M+H), Rt. 4.2 min, 77.4% (Max).

[0246] Intermediate 4: 1-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine hydrochloride

##STR00231##

Step 1: tert-butyl 1-phenyl-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate and tert-butyl 2-phenyl-2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate

[0247] ##STR00232##

[0248] To a solution of intermediate 3 (1.5 g, 5.90 mmol) in ethanol (15 mL), phenyl hydrazine (0.76 g, 7.08 mmol) was added under nitrogen atmosphere and the reaction mixture was heated at 85 C. for 8 h. Completion of the reaction was monitored by TLC, then the reaction mixture was concentrated under vacuum and the resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 20-30% EtOAc in pet ether) to afford the mixture of regioisomers. The resulting mixture was then separated by Prep HPLC (Method B) and the structure of each regioisomer was confirmed by NOESY experiments.

[0249] Isomer 1: Yield: 11% (190 mg, brown solid). .sup.1H NMR (400 MHz, CDCl.sub.3): 7.52-7.48 (m, 5H), 7.38-7.34 (m, 1H), 4.54 (s, 2H), 3.78-3.62 (m, 2H), 2.87 (t, J=5.6 Hz, 2H), 1.53 (s, 9H). LCMS: (Method A) 300.3 (M+H), Rt. 4.7 min, 97.1% (Max).

[0250] Isomer 2: Yield: 26% (450 mg, brown solid). .sup.1H NMR (400 MHz, CDCl.sub.3): 7.71 (s, 1H), 7.66-7.64 (m, 2H), 7.47-7.43 (m, 2H), 7.31-7.26 (m, 1H), 4.58 (s, 2H), 3.85-3.72 (m, 2H), 2.91-2.88 (m, 2H), 1.52 (s, 9H). LCMS: (Method A) 300.3 (M+H), Rt. 4.8 min, 99.0% (Max).

Step 2: 1-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, hydrochloride

[0251] ##STR00233##

[0252] To a stirred solution of tert-butyl 1-phenyl-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (Isomer 1) (190 mg, 0.63 mmol) in dry 1,4-dioxane (3 mL) at 0 C., HCl solution in dioxane (2 mL, 4M) was added dropwise and the reaction mixture was stirred at RT for 6 h. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated under vacuum and the resulting crude material was triturated with diethyl ether (5 mL), filtered under nitrogen atmosphere to afford the title compound. Yield: 94% (0.14 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.39-9.15 (m, 2H), 7.68 (s, 1H), 7.57-7.53 (m, 4H), 7.45-7.41 (m, 1H), 4.21-4.19 (m, 2H), 3.38-3.35 (m, 2H), 3.11 (t, J=6.0 Hz, 2H). LCMS: (Method A) 200.0 (M+H), Rt. 1.7 min, 99.7% (Max).

Intermediate 5: 2-phenyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine hydrochloride

[0253] ##STR00234##

[0254] To a stirred solution of tert-butyl 2-phenyl-2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (see synthesis of Intermediate 4, step 1, Isomer 2) (450 mg, 1.50 mmol) in dry 1,4-dioxane (4 mL) at 0 C., HCl solution in dioxane (2 mL, 4M) was added dropwise and the reaction mixture was stirred at RT for 6 h. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated under vacuum. The resulting crude material was triturated with diethyl ether (8 mL) and filtered under nitrogen atmosphere to afford the title compound. Yield: 88% (0.31 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.52-9.50 (m, 2H), 8.40 (s, 1H), 7.80-7.77 (m, 2H), 7.51-7.48 (m, 2H), 7.33-7.29 (m, 1H), 4.23 (t, J=4.4 Hz, 2H), 3.44-3.42 (m, 2H), 3.00 (t, J=6.4 Hz, 2H). LCMS: (Method A) 200.2 (M+H), Rt. 2.0 min, 97.8% (Max).

Example 1: N-(6-(1-(benzo[d][1,3]dioxol-5-yl)ethyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-2-yl)acetamide

[0255] ##STR00235##

Step 1: t-Butyl 2-amino-7,8-dihydropyrido[4,3-d]pyrimidine-6(5H)-carboxylate

[0256] ##STR00236##

[0257] To a stirred solution of intermediate 3 (2.5 g, 9.84 mmol) in ethanol (62 mL), KOAc (3.7 g, 88.58 mmol) and guanidine hydrochloride (4.3 g, 44.29 mmol) were added at RT and the reaction mixture was stirred at 80 C. for 48 h. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated under vacuum and the resulting mixture was dissolved in 10% methanol in DCM. The organic layer was washed with saturated NaHCO.sub.3 (30 mL), brine solution (30 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by recrystalization with diethyl ether to afford the title compound. Yield: 29% (600 mg, white solid). .sup.1H NMR (300 MHz, DMSO-d.sub.6): 8.03 (s, 1H), 6.41 (s, 2H), 4.03 (s, 2H), 3.57-3.53 (t, J=5.9 Hz, 2H), 2.71 (m, 2H), 1.46 (s, 9H). LCMS: (Method B) 251.2 (M+H), Rt. 4.1 min, 98.2% (Max).

Step 2: tert-butyl 2-acetamido-7,8-dihydropyrido[4,3-d]pyrimidine-6(5H)-carboxylate

[0258] ##STR00237##

[0259] To a stirred solution of t-Butyl 2-amino-7,8-dihydropyrido[4,3-d]pyrimidine-6(5H)-carboxylate (0.6 g, 2.4 mmol) in dry pyridine (4 mL), acetic anhydride (0.3 mL, 2.88 mmol) was added at RT and the reaction mixture was stirred at 80 C. for 3 h. Completion of the reaction was monitored by TLC, then the reaction mixture was concentrated under vacuum and the resulting mixture was dissolved in 5% methanol in DCM. The organic layer was washed with HCl (0.5 N, 30 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 50-60% EtOAc in hexane) to afford the title compound. Yield: 71% (500 mg, off white solid). LCMS: (Method B) 293.1 (M+H), Rt. 3.9 min, 81.4% (Max).

Step 3: N-(5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-2-yl)acetamide hydrochloride

[0260] ##STR00238##

[0261] To a stirred solution of tert-butyl 2-acetamido-7,8-dihydropyrido[4,3-d]pyrimidine-6(5H)-carboxylate (0.5 g, 1.71 mmol) in dry 1,4-dioxane (1 mL), HCl solution in dioxane (4 mL, 4M) was added dropwise at RT and the reaction mixture was stirred for 1 h. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated under vacuum and the resulting crude material was washed with diethyl ether to afford the title compound. Yield: 99% (320 mg, yellow solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 10.63 (s, 1H), 9.70 (m, 2H), 4.25 (s, 2H), 3.44 (m, 2H), 3.01 (t, J=6.3 Hz, 2H), 2.15 (s, 3H).

Step 4: N-(6-(1-(Benzo[d][1,3]dioxol-5-yl)ethyl)-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-2-yl)acetamide

[0262] ##STR00239##

[0263] To a stirred solution of N-(5,6,7,8-tetrahydropyrido[4,3-d]pyrimidin-2-yl)acetamide hydrochloride (140 mg, 0.7 mmol) in MeCN (5 mL), TEA (1 mL, 7.1 mmol) and intermediate 1 (300 mg, 1.45 mmol) were added at RT and the reaction mixture was heated at 70 C. overnight. Completion of the reaction was monitored by TLC, then the reaction mixture was evaporated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 1-2% methanol in DCM) to afford the title compound. Yield: 9% (26.61 mg, pale yellow solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 10.37 (s, 1H), 8.33 (s, 1H), 6.93 (d, J=1.2 Hz, 1H), 6.88-6.86 (m, 1H), 6.82-6.80 (m, 1H), 6.00 (d, J=2.8 Hz, 2H), 3.65-3.58 (m, 2H), 3.46-3.41 (m, 1H), 2.77-2.75 (m, 3H), 2.67-2.62 (m, 1H), 2.14 (s, 3H), 1.35 (d, J=6.8 Hz, 3H). LCMS: (Method A) 341.0 (M+H), Rt. 1.8 min, 95.8% (Max). HPLC: (Method A) Rt. 1.8 min, 97.2% (Max).

Example 2: 2-(1-(benzo[d][1,3]dioxol-5-yl)ethyl)-1,2,3,4-tetrahydroisopuinoline

[0264] ##STR00240##

[0265] To a stirred solution of 1,2,3,4-tetrahydro isoquinoline (0.29 g, 2.18 mmol) in MeCN (10 mL), TEA (1 mL, 7.10 mmol) and intermediate 1 (0.5 g, 2.72 mmol) were added at RT and the reaction mixture was heated at 90 C. overnight. Completion of the reaction was monitored by TLC, then the reaction mixture was concentrated under vacuum and resulting mixture was dissolved in DCM (20 mL). The organic layer was washed with water (5 mL), brine solution (10 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by MD Auto Prep (method A) to afford the title compound. Yield: 2% (17.64 mg, colorless gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.11-7.07 (m, 3H), 7.05-7.01 (m, 1H), 7.00-6.99 (m, 1H), 6.92-6.85 (m, 1H), 6.81-6.80 (m, 1H), 5.99 (d, J=2.0 Hz, 2H), 3.68-3.64 (m, 1H), 3.54-3.45 (m, 2H), 2.74-2.66 (m, 2H), 2.65-2.64 (m, 1H), 2.51-2.50 (m, 1H), 1.35 (d, J=6.4 Hz, 3H). LCMS: (Method A) 282.1 (M+H), Rt. 2.8 min, 98.6% (Max). HPLC: (Method A) Rt. 2.9 min, 98.7% (Max).

Example 3: N-(5-Phenethyl-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-yl)acetamide

[0266] ##STR00241##

Step 1: t-Butyl 2-amino-6,7-dihydrothiazolo[5,4-c]pyridine-5(4-carboxylate

[0267] ##STR00242##

[0268] To a solution of t-butyl 3-bromo-4-oxopiperidine-1-carboxylate (1.0 g, 3.59 mmol) in isopropanol (10 mL), thiourea (0.33 g, 4.30 mmol) was added and the reaction mixture was refluxed at 90 C. for 1 h. Completion of the reaction was monitored by TLC. The reaction mixture was then concentrated under vacuum and the resulting crude material was washed with diethyl ether to afford the title compound. Yield: 99% (0.9 g, white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.05 (bs, 2H), 4.32 (m, 2H), 3.61-3.58 (m, 2H), 2.50 (s, 2H), 1.41 (s, 9H). LCMS: (Method A) 256.0 (M+H), Rt. 2.5 min, 64.8% (Max).

Step 2: t-Butyl 2-acetamido-6,7-dihydrothiazolo[5,4-c]pyridine-5(4H)-carboxylate

[0269] ##STR00243##

[0270] To a stirred solution of t-Butyl 2-amino-6,7-dihydrothiazolo[5,4-c]pyridine-5(4H)-carboxylate (0.9 g, 3.52 mmol) in TEA (5 mL), acetic anhydride (0.43 mL, 4.58 mmol) was added at 0 C. and the reaction mixture was stirred at RT overnight. Completion of the reaction was monitored by TLC, the reaction mixture was concentrated under vacuum and the resulting mixture was dissolved in EtOAc (20 mL). The organic layer was washed with brine solution (5 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was used in the next step as such without any further purification. Yield: 82% (0.85 g, pale yellow liquid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 11.9 (bs, 1H), 4.46 (m, 2H), 3.63-3.44 (m, 2H), 2.62-2.49 (m, 2H), 2.21 (s, 3H), 1.41 (s, 9H). LCMS: (Method A) 298.0 (M+H), Rt. 3.4 min, 94.5% (Max).

Step 3: N-(4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-yl)acetamide hydrochloride

[0271] ##STR00244##

[0272] To a stirred solution of t-Butyl 2-acetamido-6,7-dihydrothiazolo[5,4-c]pyridine-5(4H)-carboxylate (0.35 g, 3.36 mmol) in dry 1,4-dioxane, HCl solution in dioxane (4 M, 7 mL) was added dropwise at RT and the reaction mixture was stirred for 1 h. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated under vacuum and the resulting crude material was triturated with diethyl ether to afford the title compound. Yield: 99% (500 mg, off white solid).

Step 4: N-(5-(1-(benzo[d][1,3]dioxol-5-yl)ethyl)-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-yl)acetamide

[0273] ##STR00245##

[0274] To a stirred solution of N-(4,5,6,7-tetrahydrothiazolo[5,4-c]pyridin-2-yl)acetamide hydrochloride (0.3 g, 1.52 mmol) in MeCN (3 mL), TEA (0.65 mL, 4.56 mmol) and intermediate 1 (0.28 g, 1.52 mmol) were added at RT and the reaction mixture was stirred at 80 C. overnight. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated under vacuum and the resulting crude material was dissolved in EtOAc (20 mL). The organic layer was washed with water (10 mL), brine solution (10 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The crude resulting material was purified by flash chromatography (Biotage Isolera, eluent: 1-3% methanol in DCM) to afford the title compound. Yield: 3% (2.87 mg, yellow solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 11.90 (s, 1H), 6.92 (d, J=1.4 Hz, 1H), 6.85 (d, J=8.0 Hz, 1H), 6.80 (d, J=8.0 Hz, 1H), 5.99 (d, J=2.0 Hz, 2H), 3.67-3.34 (m, 3H), 2.92-2.89 (m, 1H), 2.59-2.50 (m, 3H), 2.10 (s, 3H), 1.30 (d, J=6.8 Hz, 3H). LCMS: (Method B) 346.0 (M+H), Rt. 4.8 min, 96.9% (Max). HPLC: (Method A) Rt. 2.3 min, 97.8% (Max).

Example 4: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0275] ##STR00246##

Step 1: 4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0276] ##STR00247##

[0277] To a stirred solution of intermediate 3 (3 g, 11.8 mmol) in dry ethanol (15 mL), hydrazine hydrochloride (0.47 g, 9.4 mmol) was added and the reaction mixture was heated at 85 C. in sealed tube for 4 h. It was evaporated under vacuum and HCl in methanol (20 mL, 4M) was added dropwise at 0 C. under nitrogen atmosphere. The mixture was stirred for 12 h at RT. Completion of the reaction was monitored by TLC. The reaction mixture was concentrated under vacuum and the resulting crude material was used in the next step as such without any further purification. Yield: 69% (1.0 g, yellow solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.28 (s, 2H), 7.55 (s, 1H), 4.11 (s, 2H), 3.51-3.40 (m, 2H), 2.89 (t, J=6.0 Hz, 2H). LCMS: (Method B) 124.0 (M+H), Rt. 0.7 min, 99.3% (Max).

Step 3: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0278] ##STR00248##

[0279] To a stirred solution of 4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (0.1 g, 0.8 mmol) in DMF (10 mL), TEA (0.35 mL, 2.4 mmol) and intermediate 2 (0.221 g, 1.2 mmol) were added at 0 C. and the reaction mixture was stirred at 90 C. overnight. Completion of the reaction was monitored by TLC. The reaction mixture was evaporated at 50 C. under vacuum. The resulting mixture was dissolved in DCM (10 mL) and the organic layer was washed with water (5 mL), brine solution (5 mL) and dried over anhydrous Na.sub.2SO.sub.4. The organic layer was evaporated under vacuum and the resulting crude material was purified by flash chromatography (8% methanol in DCM). The resulting material was further purified by prep HPLC (Method B). After evaporation of the solvents, the material was triturated with DCM (5 mL) to afford the title compound. Yield: 6% (12 mg, white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 12.28 (s, 1H), 7.34 (s, 1H), 7.14 (d, J=7.6 Hz, 1H), 6.78 (d, J=7.6 Hz, 1H), 6.73 (s, 1H), 4.49 (t, J=8.8 Hz, 2H), 3.52 (t, J=6.4 Hz, 2H), 3.13 (t, J=8.8 Hz, 2H), 2.67-2.66 (m, 1H), 2.50-2.49 (m, 4H), 1.30 (d, J=6.4 Hz, 3H). LCMS: (Method A) 270.2 (M+H), Rt. 2.0, 98.7% (Max). HPLC: (Method A) Rt. 2.4 min, 98.9% (Max).

Example 5: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(4-fluorophenyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0280] ##STR00249##

Step 1: tert-butyl-1-(4-fluorophenyl)-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate and tert-butyl-2-(4-fluorophenyl)-2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (regiosiomers)

[0281] ##STR00250##

[0282] To a stirred solution of intermediate 3 (1.5 g, 5.90 mmol) in ethanol (15 mL), 4-fluoro phenyl hydrazine hydrochloride (1.15 g, 7.08 mmol) and TEA (1.6 mL, 11.8 mmol) were added under nitrogen atmosphere and the reaction mixture was heated at 85 C. for 8 h. Completion of the reaction was monitored by TLC. The reaction mixture was then concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 15-20% EtOAc in pet ether) to afford the title compound as a mixture of regioisomers. The obtained material was separated by Prep HPLC (Method B).

[0283] Isomer 1: Yield: 16% (300 mg, brown gummy oil). .sup.1H NMR (400 MHz, CDCl.sub.3): 7.52 (s, 1H), 7.48-7.45 (m, 2H), 7.17 (t, J=8.8 Hz, 2H), 4.54-4.51 (m, 2H), 3.72-3.70 (m, 2H), 2.82 (t, J=4.8 Hz, 2H), 1.52 (s, 9H). LCMS: (Method A) 318.3 (M+H), Rt. 4.8 min, 91.2% (Max).

[0284] Isomer 2: Yield: 17% (320 mg, brown solid). .sup.1H NMR (400 MHz, CDCl.sub.3): 7.64-7.58 (m, 3H), 7.14 (t, J=12.0 Hz, 2H), 4.59-4.57 (m, 2H), 3.78-3.76 (m, 2H), 2.89-2.87 (m, 2H), 1.51 (s, 9H). LCMS: (Method A) 318.3 (M+H), Rt. 4.9 min, 99.9% (Max).

Step 3: 1-(4-fluorophenyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine hydrochloride

[0285] ##STR00251##

[0286] To a stirred solution of tert-butyl-1-(4-fluorophenyl)-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (isomer 1) (300 mg, 0.94 mmol) in dry 1,4-dioxane (3 mL) at 0 C., HCl solution in dioxane (1 mL, 4M) was added dropwise and the reaction mixture was stirred at RT for 6 h. Completion of the reaction was monitored by TLC; the reaction mixture was then concentrated under vacuum. The resulting crude material was triturated with diethyl ether (5 mL) and filtered under nitrogen atmosphere to afford the title compound. Yield: 92% (0.22 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.36-9.35 (m, 2H), 7.67 (s, 1H), 7.62-7.58 (m, 2H), 7.39 (t, J=11.6 Hz, 2H), 4.18-4.20 (m, 2H), 3.39-3.37 (m, 2H), 3.07 (t, J=7.2 Hz, 2H). LCMS: (Method A) 218.2 (M+H), Rt. 1.8 min, 93.5% (Max).

Step 4: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(4-fluorophenyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0287] ##STR00252##

[0288] To a stirred solution of 1-(4-fluorophenyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine hydrochloride (220 mg, 0.86 mmol) in dry MeCN (2 mL), intermediate 2 (190 mg, 1.04 mmol) and TEA (0.35 mL, 2.60 mmol) were added and the reaction mixture was heated at 90 C. for 6 h. Completion of the reaction was monitored by TLC, then the reaction mixture was concentrated under under vacuum. To the resulting mixture, water (5 mL) was added and the aqueous layer was extracted with DCM (35 mL). The combined organic layer was washed with brine solution (5 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 30% EtOAc in pet ether) to afford the title compound. Its structure has been confirmed by NOESY. Yield: 2.5% (7.9 mg, yellow gummy liquid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.63-7.59 (m, 2H), 7.47 (s, 1H), 7.34-7.30 (m, 2H), 7.17 (d, J=7.6 Hz, 1H), 6.82 (d, J=7.2 Hz, 1H), 6.78 (s, 1H), 4.52 (t, J=8.4 Hz, 2H), 3.61-3.57 (m, 2H), 3.41-3.39 (m, 1H), 3.15 (t, J=8.8 Hz, 2H), 2.81-2.72 (m, 3H), 2.58-2.52 (m, 1H), 1.35 (d, J=6.4 Hz, 3H). LCMS: (Method A) 364.2 (M+H), Rt. 3.2 min, 98.3% (Max). HPLC: (Method A) Rt. 3.2 min, 97.9% (Max).

Example 6: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(4-fluorophenyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0289] ##STR00253##

Step 1: 2-(4-fluorophenyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine hydrochloride

[0290] ##STR00254##

[0291] To a stirred solution of tert-butyl-2-(4-fluorophenyl)-2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (synthesis described in example 5, step 1, isomer 2) (320 mg, 1.01 mmol) in dry 1,4-dioxane (3 mL) at 0 C., HCl solution in dioxane (4M, 1 mL) was added and the reaction mixture was stirred at RT for 6 h. Completion of the reaction was monitored by TLC; then the reaction mixture was concentrated under vacuum. The resulting crude material was triturated with diethyl ether (5 mL), filtered under nitrogen atmosphere to afford the title compound. Yield: 90% (0.23 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.27 (s, 1H), 8.40 (s, 1H), 7.79 (d, J=10.0 Hz, 2H), 7.50 (t, J=10.4 Hz, 2H), 7.31 (t, J=9.6 Hz, 1H), 4.25 (s, 2H), 3.46-3.43 (m, 2H), 2.99 (t, J=8.4 Hz, 2H). LCMS: (Method A) 218.2 (M+H), Rt. 2.1 min, 96.1% (Max).

Step 2: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(4-fluorophenyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0292] ##STR00255##

[0293] To a stirred solution of 2-(4-fluorophenyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine hydrochloride (270 mg, 1.06 mmol) in dry DMF (3 mL), intermediate 2 (194 mg, 1.06 mmol) and TEA (0.32 g, 3.20 mmol) were added and the reaction mixture was heated at 90 C. for 6 h. Completion of the reaction was monitored by TLC, then the reaction mixture was concentrated under vacuum. To the resulting mixture, water (2 mL) was added and the aqueous layer was extracted with DCM (34 mL). The combined organic layer was washed with brine solution (4 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 1-2% methanol in DCM) and the obtained material was further purified by Prep HPLC (Method B) to afford the title compound. Yield: 6% (22 mg, brown gummy solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.12 (s, 1H), 7.77-7.73 (m, 2H), 7.32-7.27 (m, 2H), 7.17 (d, J=7.6 Hz, 1H), 6.82 (d, J=7.6 Hz, 1H), 6.77 (s, 1H), 4.51 (t, J=8.4 Hz, 2H), 3.61-3.56 (m, 2H), 3.42-3.39 (m, 1H), 3.15 (t, J=8.8 Hz, 2H), 2.80-2.72 (m, 1H), 2.68-2.66 (m, 3H), 1.35 (d, J=6.4 Hz, 3H). LCMS: (Method A) 364.2 (M+H), Rt. 3.3 min, 98.7% (Max). HPLC: (Method A) Rt. 3.0 min, 99.2% (Max).

Example 7: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0294] ##STR00256##

[0295] To a stirred solution of intermediate 4 (140 mg, 0.59 mmol) in dry MeCN, intermediate 2 (130 mg, 0.71 mmol) and TEA (0.24 mL, 1.78 mmol) were added and the reaction mixture was heated at 90 C. overnight. Completion of the reaction was monitored by TLC; then the reaction mixture was concentrated under vacuum. To the resulting mixture, water (2 mL) was added and was extracted with DCM (33 mL). The combined organic layer was washed with brine solution (3 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 35% EtOAc in pet ether) to afford the title compound. Yield: 13% (25 mg, brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.59-7.57 (m, 2H), 7.51-7.47 (m, 3H), 7.36-7.34 (m, 1H), 7.18-7.16 (m, 1H), 6.84-6.82 (m, 1H), 6.78 (s, 1H), 4.52 (t, J=8.8 Hz, 2H), 3.61-3.57 (m, 2H), 3.41-3.39 (m, 1H), 3.15 (t, J=8.4 Hz, 2H), 2.83-2.71 (m, 3H), 2.58-2.55 (m, 1H), 1.35 (d, J=6.4 Hz, 3H). LCMS: (Method A) 346.2 (M+H), Rt. 3.0 min, 95.7% (Max). HPLC: (Method A) Rt. 3.1 min, 95.6% (Max).

Example 8: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-phenyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0296] ##STR00257##

[0297] To a stirred solution of 2-phenyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine hydrochloride (Intermediate 5, 310 mg, 1.31 mmol) in dry MeCN, intermediate 2 (480 mg, 2.63 mmol) and TEA (0.54 mL, 3.95 mmol) were added and the reaction mixture was heated at 90 C. overnight. Completion of the reaction was monitored by TLC; then the reaction mixture was concentrated under vacuum. To the resulting mixture, water (3 mL) was added and was extracted with DCM (35 mL). The combined organic layer was washed with brine solution (5 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 35% EtOAc in pet ether) to afford the title compound. Yield: 14% (66 mg, brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.13 (s, 1H), 7.71 (d, J=8.0 Hz, 2H), 7.45-7.42 (m, 2H), 7.24-7.15 (m, 2H), 6.82-6.76 (m, 2H), 4.51 (t, J=3.2 Hz, 2H), 3.61-3.56 (m, 2H), 3.42-3.38 (m, 1H), 3.17-3.12 (m, 2H), 2.76-2.65 (m, 4H), 1.35-1.33 (m, 3H). LCMS: (Method A) 346.3 (M+H), Rt. 3.2 min, 96.9% (Max). HPLC: (Method A) Rt. 3.2 min, 98.7% (Max).

Example 9: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(pyridin-2-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0298] ##STR00258##

Step 1: 2-hydrazinylpyridine

[0299] ##STR00259##

[0300] To a stirred solution of 2-chloropyridine (3 g, 26.42 mmol) in ethanol (30 mL), hydrazine hydrate (10.56 mL, 211.3 mmol) was added and the reaction mixture was refluxed at 80 C. for 20 h. Completion of the reaction was monitored by TLC; the reaction mixture was then evaporated under vacuum. The resulting crude material was basified with sodium hydroxide (5 mL, 1N) and the aqueous layer was extracted with DCM (250 mL). The combined organic layer was dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was used as such to the next step without any further purification. Yield: 93% (2.6 g, colourless liquid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.97 (t, J=9.2 Hz, 1H), 7.41 (t, J=6.8 Hz, 1H), 7.36 (d, J=8.0 Hz, 1H), 6.68 (d, J=8.9 Hz, 1H), 6.53 (t, J=6.4 Hz, 1H), 4.08 (s, 2H). LCMS: (Method A) 110.1 (M+H), Rt. 0.6 min, 85.3% (Max).

Step 2: tert-butyl 1-(pyridin-2-yl)-1,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate and tert-butyl 2-(pyridin-2-yl)-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate

[0301] ##STR00260##

[0302] To a stirred solution of intermediate 3 (3 g, 11.81 mmol) in DMF (20 mL), TEA (4.92 mL, 35.4 mmol) and 2-hydrazinylpyridine (1.54 g, 14.17 mmol) were added and the reaction mixture was heated at 80 C. for 8 h. Completion of the reaction was monitored by TLC; the reaction mixture was then evaporated under vacuum. To the resulting mixture, water (5 mL) was added and was extracted with EtOAc (250 mL). The combined organic layer was washed with brine solution (20 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 30% EtOAc in hexane). The pyrazole regioisomers mixture was separated by prep-HPLC (method A) to afford tert-butyl 1-(pyridin-2-yl)-1,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate (Fraction 1) and tert-butyl 2-(pyridin-2-yl)-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate (Fraction 2).

[0303] Fraction 1: Yield: 23% (800 mg, brown gummy oil). LCMS: (Method A) 301.2 (M+H), Rt. 4.5 min, 84.2% (Max). HPLC: (Method A), Rt. 4.0 min, 82.2% (Max).

[0304] Fraction 2: Yield: 34% (1.2 g, brown gummy oil). LCMS: (Method A) 301.2 (M+H), Rt. 2.4 min, 65.4% (Max). HPLC: (Method A), Rt. 2.4 min, 68.0% (Max).

Step 3: 1-(pyridin-2-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine

[0305] ##STR00261##

[0306] To a stirred solution of tert-butyl 1-(pyridin-2-yl)-1,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate (Fraction 1, 800 mg, 26.66 mmol) in dry 1,4-dioxane (10 mL), HCl solution in dioxane (13.33 mL, 4M) was added dropwise at 0 C. and the reaction mixture was stirred at RT for 3 h. Completion of the reaction was monitored by TLC; the reaction mixture was then evaporated under vacuum. The resulting crude material was triturated with EtOAc, hexane and diethyl ether to afford the title compound. Yield: 84% (450 mg, off white solid). LCMS: (Method B) 201.2 (M+H), Rt. 3.4 min, 96.0% (Max). HPLC: (Method B), Rt. 3.6 min, 91.5% (Max).

Step 4: 6-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(pyridin-2-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine

[0307] ##STR00262##

[0308] To a stirred solution of 1-(pyridin-2-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine (414 mg, 1.12 mmol) in MeCN (10 mL), TEA (0.4 mL, 2.80 mmol) and intermediate 2 (170 mg, 0.93 mmol) were added at RT and the reaction mixture was heated at 80 C. overnight. After completion of the reaction (monitored by TLC), the reaction mixture was evaporated under vacuum. To the resulting mixture, water (5 mL) was added and was extracted with EtOAc (250 mL). The combined organic layer was washed with brine solution (20 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 50% EtOAc in hexane) to afford the title compound. Yield: 12% (97.49 mg, brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d): 8.41 (d, J=4.0 Hz, 1H), 7.93 (t, J=7.2 Hz, 1H), 7.86 (d, J=8.4 Hz, 1H), 7.54 (s, 1H), 7.29 (t, J=7.2 Hz, 1H), 7.17 (d, J=7.6 Hz, 1H), 6.82 (d, J=7.2 Hz, 1H), 4.51 (t, J=8.8 Hz, 2H), 3.60-3.58 (m, 1H), 3.56-3.52 (m, 1H), 3.40-3.33 (m, 1H), 3.17-3.13 (m, 5H), 2.76-2.73 (m, 1H), 2.67-2.63 (m, 1H), 1.3 (d, J=6.4 Hz, 3H). LCMS: (Method A) 347.2 (M+H), Rt. 2.7 min, 91.8% (Max). HPLC: (Method A), Rt. 3.0 min, 93.1% (Max).

Example 10: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(pyridin-2-yl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0309] ##STR00263##

Step 1: tert-butyl 2-(pyridin-2-yl)-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate

[0310] ##STR00264##

[0311] The title compound was synthesized according the protocol described for Example 9, steps 1 and 2. The pyrazole regioisomers mixture was separated by prep-HPLC (method A) to afford the title compound as Fraction 2. Yield: 34% (1.2 g, brown gummy oil). LCMS: (Method A) 301.2 (M+H), Rt. 2.4 min, 65.4% (Max). HPLC: (Method A), Rt. 2.4 min, 68.0% (Max).

Step 2: 2-(pyridin-2-yl)-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-c]pyridine

[0312] ##STR00265##

[0313] To a stirred solution of tert-butyl 2-(pyridin-2-yl)-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate (1.2 g, 4.0 mmol) in dry 1,4-dioxane (10 mL) at 0 C., HCl solution in dioxane (10 mL, 40 mmol, 4M) was added dropwise and the reaction mixture was stirred at RT for 3 h. After completion of the reaction (monitored by TLC), the reaction mixture was evaporated under vacuum. The resulting crude material was triturated with EtOAc, hexane and diethyl ether to afford the title compound which was forwarded to the next step as such without any further purification. Yield: 88% (700 mg, yellow solid). LCMS: (Method B) 201.2 (M+H), Rt. 3.4 min, 86.7% (Max). HPLC: (Method B), Rt. 3.2 min, 67.9% (Max).

Step 3: 6-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(pyridin-2-yl)-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-c]pyridine

[0314] ##STR00266##

[0315] To a stirred solution of 1-(pyridin-2-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine hydrochloride (652 mg, 3.26 mmol) in MeCN (10 mL), intermediate 2 (495 mg, 2.71 mmol) followed by TEA (1.52 mL, 10.8 mmol) were added and the reaction mixture was heated at 80 C. overnight. Completion of the reaction was monitored by TLC; the reaction mixture was then evaporated under vacuum. To the resulting mixture, water (5 mL) was added and was extracted with EtOAc (225 mL). The combined organic layer was washed with brine solution (25 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by prep. HPLC (method B) to afford the title compound. Yield: 16% (130.75 mg, brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.40 (d, J=6.8 Hz, 1H), 8.30 (s, 1H), 7.91 (t, J=9.2 Hz, 1H), 7.81 (d, J=8.4 Hz, 1H), 7.27 (t, J=5.2 Hz, 1H), 7.16 (d, J=7.6 Hz, 1H), 6.81 (d, J=8.8 Hz, 1H), 6.76 (s, 1H), 4.51 (t, J=8.8 Hz, 2H), 3.63-3.61 (m, 3H), 3.44-3.35 (m, 2H), 3.16-3.12 (m, 2H), 2.69-2.66 (m, 2H), 1.34 (d, J=6.8 Hz, 3H). LCMS: (Method A) 347.2 (M+H), Rt. 2.6 min, 99.5% (Max). HPLC: (Method A), Rt. 2.9 min, 99.5% (Max).

Example 11: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(4-fluorophenyl)-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine

[0316] ##STR00267##

Step 1: 2-(4-fluorophenyl)-4, 5,6,7-tetrahydrothiazolo[5,4-c]pyridine

[0317] ##STR00268##

[0318] To the stirred solution of 4-fluorobenzothioamide (0.38 g, 2.45 mmol) in isopropyl alcohol (10 mL), tert-butyl 3-bromo-4-oxopiperidine-1-carboxylate (0.68 g, 2.45 mmol) was added at RT and the reaction mixture was stirred at 90 C. overnight. Completion of the reaction was monitored by TLC. The reaction mixture was then evaporated under vacuum and was basified using saturated Na.sub.2CO.sub.3 (20 mL). The aqueous layer was extracted with EtOAc (250 mL) and the combined organic layer was washed with water (15 mL), brine solution (15 mL) and dried over anhydrous Na.sub.2SO.sub.4. The organic layer was evaporated under vacuum to afford the title compound that was used in the next step as such without any further purification. Yield: 65% (0.5 g, brown solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.95-7.91 (m, 2H), 7.35-7.30 (m, 2H), 3.94 (d, J=1.6 Hz, 2H), 3.04-3.01 (m, 2H), 2.74 (t, J=4.0 Hz, 2H), 1.34 (s, 9H). LCMS: (Method A) 335.3 (M+H), Rt. 2.4 min, 84.3% (Max).

Step 2: 2-(4-fluorophenyl)-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine hydrochloride

[0319] ##STR00269##

[0320] To the stirred solution of tert-butyl 2-(4-fluorophenyl)-6,7-dihydrothiazolo[5,4-c]pyridine-5(4H)-carboxylate (0.5 g, 1.4 mmol) in dry 1,4-dioxane (5 mL), HCl solution in dioxane (4 mL, 4M) was added dropwise at RT and the reaction mixture was stirred for 4 h. Completion of the reaction was monitored by TLC; the reaction mixture was then concentrated under vacuum. The resulting crude material was triturated with EtOAc (25 mL) to afford the title compound. Yield: 65% (0.4 g, brown solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.95-7.91 (m, 3H), 7.35-7.30 (m, 2H), 3.94 (d, J=1.6 Hz, 2H), 3.04-3.01 (m, 2H), 2.74 (t, J=4.0 Hz, 2H). LCMS: (Method A) 235.3 (M+H), Rt. 2.4 min, 84.3% (Max).

Step 3: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(4-fluorophenyl)-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine

[0321] ##STR00270##

[0322] To the stirred solution of 2-(4-fluorophenyl)-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine hydrochloride (0.5 g, 2.17 mmol) in DMF (10 mL), TEA (1.2 mL, 8.68 mmol) and intermediate 2 (0.59 g, 3.25 mmol) were added at RT and the reaction mixture was heated at 60 C. overnight. Completion of the reaction was monitored by TLC. The reaction mixture was then quenched with water and was extracted with EtOAc (225 mL). The combined organic layer was washed with water (5 mL), brine solution (5 mL), dried over anhydrous Na.sub.2SO.sub.4 and evaporated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 40% EtOAc in pet ether) to afford the title compound. Yield: 5% (0.04 g, pale yellow solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.93-7.90 (m, 2H), 7.34-7.30 (m, 2H), 7.18 (d, J=7.6 Hz, 1H), 6.83 (s, 1H), 6.81-6.77 (m, 1H), 4.52 (t, J=8.8 Hz, 2H), 3.84-3.80 (m, 1H), 3.65-3.51 (m, 2H), 3.16 (t, J=8.8 Hz, 2H), 2.88-2.76 (m, 2H), 2.72-2.70 (m, 2H), 1.36 (d, J=6.8 Hz, 3H). LCMS: (Method A) 381.2 (M+H), Rt. 3.5 min, 92.9% (Max). HPLC: (Method A) Rt. 3.2 min, 94.1% (Max).

Example 12 and Example 13: (R)-5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-phenyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine and (S)-5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-phenyl-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0323] ##STR00271##

[0324] The two enantiomers of Example 8 were separated by SFC (Method A: mobile phase: 20 mM ammonia in IPA, column: Lux A1). The first eluting product was associated to Example 12 and the second eluting compound was associated to Example 13.

[0325] Analysis of first eluting fraction (Example 12): Yield: 4% (10 mg, yellow gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.14 (s, 1H), 7.72 (d, J=8.4 Hz, 2H), 7.46-7.42 (m, 2H), 7.23 (t, J=7.2 Hz, 1H), 7.16 (d, J=7.2 Hz, 1H), 6.81 (d, J=7.6 Hz, 1H), 6.76 (s, 1H), 4.51 (t, J=8.4 Hz, 2H), 3.58 (t, J=5.6 Hz, 2H), 3.42-3.39 (m, 1H), 3.14 (t, J=8.8 Hz, 2H), 2.76-2.74 (m, 2H), 2.67 (d, J=7.6 Hz, 2H), 1.34 (d, J=6.4 Hz, 3H). LCMS: (Method A) 346.3 (M+H), Rt. 3.1 min, 97.4% (Max). HPLC: (Method A) Rt. 3.1 min, 97.3% (Max). Chiral SFC: (Method A) Rt. 8.98 min, 99.54% (Max).

[0326] Analysis of second eluting fraction (Example 13): Yield: 3% (7 mg, brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.14 (s, 1H), 7.72 (d, J=8.4 Hz, 2H), 7.46-7.42 (m, 2H), 7.23 (t, J=7.2 Hz, 1H), 7.16 (d, J=7.2 Hz, 1H), 6.81 (d, J=7.6 Hz, 1H), 6.76 (s, 1H), 4.51 (t, J=8.0 Hz, 2H), 3.58 (t, J=4.8 Hz, 2H), 3.42-3.39 (m, 1H), 3.14 (t, J=8.8 Hz, 2H), 2.76-2.74 (m, 2H), 2.67 (d, J=7.6 Hz, 2H), 1.34 (d, J=6.4 Hz, 3H). LCMS: (Method A) 346.3 (M+H), Rt. 3.1 min, 97.2% (Max). HPLC: (Method A) Rt. 3.1 min, 97.7% (Max). Chiral SFC: (Method A) Rt. 10.0 min, 98.5% (Max).

Example 14: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(pyrimidin-5-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0327] ##STR00272##

Step 1: 5-hydrazinylpyrimidine hydrochloride

[0328] ##STR00273##

[0329] To a stirred solution of pyrimidine-5-boronic acid (5 g, 40.3 mmol) in dry methanol (160 mL), di-tert-butyl azodicarboxylate (DTAD, 9.3 g, 40.3 mmol) and copper(II) diacetate monohydrate (0.26 g, 1.32 mmol) were added and the reaction mixture was heated at 60 C. for 1 h. Completion of the reaction was monitored by TLC. The reaction mixture was then concentrated under high vacuum and the resulting mixture was dissolved in diethyl ether (50 mL). The organic layer was washed with saturated NaHCO.sub.3 (50 mL), water (50 mL), brine solution (50 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting material was dissolved in 1,4-dioxane (50 mL), HCl solution in dioxane (20 mL, 4M) was added dropwise at 0 C. and the reaction mixture was stirred overnight. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated under vacuum and the resulting mixture was triturated with EtOAc (50 mL), filtered under nitrogen to afford the title compound. Yield: 51% (2.2 g, dark green solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 10.62-10.54 (m, 1H), 8.78 (s, 1H), 8.52-7.81 (m, 2H), 8.58 (s, 2H). LCMS: (Method B) 111.2 (M+H), Rt. 0.8 min, 68.4% (Max).

Step 2: tert-butyl 1-(pyrimidin-5-yl)-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate

[0330] ##STR00274##

[0331] To a solution of intermediate 3 (1.5 g, 5.90 mmol) in ethanol (15 mL), 5-hydrazinylpyrimidine hydrochloride (0.86 g, 5.90 mmol) and TEA (1.8 mL, 17.7 mmol) were added under nitrogen atmosphere and the reaction mixture was heated to 85 C. for 8 h. After completion of the reaction (monitored by TLC), the reaction mixture was concentrated under vacuum and the resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 70% EtOAc in pet ether) to afford the title compound. Yield: 70% (1.2 g, brown gummy liquid). LCMS: (Method A) 302.0 (M+H), Rt. 2.3 min, 56.5% (Max).

Step 3: 1-(pyrimidin-5-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine hydrochloride

[0332] ##STR00275##

[0333] To a stirred solution of tert-butyl 1-(pyrimidin-5-yl)-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (1.2 g, 3.83 mmol) in dry 1,4-dioxane (12 mL) at 0 C., HCl solution in dioxane (2.4 mL, 4M) was added dropwise and the reaction mixture was stirred at RT overnight. Completion of the reaction was monitored by TLC; the reaction mixture was then concentrated under vacuum. The resulting crude material was triturated with diethyl ether (15 mL) and filtered under nitrogen atmosphere to afford the title compound. Yield: 43% (0.41 g, brown solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.71-9.46 (m, 2H), 9.23 (s, 1H), 9.11 (s, 1H), 7.82 (s, 1H), 7.56 (s, 1H), 4.18-4.09 (m, 2H), 3.40-3.33 (m, 2H), 3.24-3.21 (m, 1H), 2.91-2.88 (m, 1H).

Step 4: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(pyrimidin-5-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0334] ##STR00276##

[0335] To a stirred solution of 1-(2,3-dihydrobenzofuran-6-yl)ethan-1-ol (Intermediate 2, steps 1 to 4; 0.4 g, 2.43 mmol) in dry DCM (10 mL) at 0 C., thionyl chloride (0.26 mL, 3.65 mmol) was added and the reaction mixture was stirred at RT for 2 h. Completion of the reaction was monitored by TLC. The reaction mixture was concentrated under vacuum and the resulting mixture was suspended in dry DMF (3 mL). 1-(Pyrimidin-5-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine hydrochloride (578 mg, 2.43 mmol) and TEA (0.74 g, 7.31 mmol) were added at RT and the reaction mixture was heated at 90 C. for 6 h. Completion of the reaction was monitored by TLC; the reaction mixture was then concentrated under vacuum. To the resulting mixture, water (4 mL) was added and was extracted with DCM (34 mL). The combined organic layer was washed with brine solution (10 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 55% EtOAc in pet ether) to afford the title compound. Yield: 4% (6.5 mg, pale brown solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.16 (s, 1H), 9.10 (s, 2H), 7.64 (s, 1H), 7.17 (d, J=7.6 Hz, 1H), 6.82 (d, J=7.2 Hz, 1H), 6.78 (s, 1H), 4.52 (t, J=8.4 Hz, 2H), 3.64-3.57 (m, 2H), 3.37-3.34 (m, 1H), 3.15 (t, J=8.4 Hz, 2H), 2.95-2.89 (m, 2H), 2.77-2.72 (m, 1H), 2.68-2.63 (m, 1H), 1.36 (d, J=6.8 Hz, 3H). LCMS: (Method A) 348.0 (M+H), Rt. 2.2 min, 93.4% (Max). HPLC: (Method A) Rt. 2.2 min, 93.6% (Max).

Example 15: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(tetrahydro-2H-pyran-4-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine or 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(tetrahydro-2H-pyran-4-yl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0336] ##STR00277##

Step 1: tert-butyl 2-(tetrahydro-2H-pyran-4-yl)hydrazine-1-carboxylate

[0337] ##STR00278##

[0338] To the stirred solution of tetrahydro-4H-pyran-4-one (2 g, 9.33 mmol), tert-butoxycarbonyl hydrazide (1.8 g, 13.99 mmol) in AcOH: MeOH (1:1, 10 mL), NaCNBH.sub.3 (0.52 g, 8.4 mmol) was added portion wise at 0 C. and the reaction mixture was stirred at RT for 30 min. Completion of the reaction was monitored by TLC; the reaction mixture was then concentrated under vacuum. The resulting mixture was suspended with 10% NaHCO.sub.3 (20 mL) and was extracted with DCM (215 mL). The combined organic layer was washed with brine (10 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum to afford the title compound. Yield: 99% (crude) (2 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.20 (s, 1H), 4.34 (s, 1H), 3.82-3.81 (m, 2H), 3.29-3.26 (m, 2H), 2.89-2.88 (m, 1H), 1.63 (t, J=2.0 Hz, 2H), 1.38 (s, 9H), 1.24 (t, J=4.0 Hz, 2H). LCMS: (Method A) 117.2 (M-Boc), Rt. 1.2 min, 99.7%.

Step 2: (tetrahydro-2H-pyran-4-yl)hydrazine hydrochloride

[0339] ##STR00279##

[0340] To the stirred solution of tert-butyl 2-(tetrahydro-2H-pyran-4-yl)hydrazine-1-carboxylate (2 g, 9.25 mmol) in dry 1,4-dioxane (6 mL), HCl solution in dioxane (10 mL, 4M) was added and the reaction mixture was stirred at RT for 2 h. Completion of reaction was monitored by TLC; the reaction mixture was then evaporated under vacuum. The resulting crude material was triturated with EtOAc twice and dried under vacuum to afford the title compound which was used in the next step as such without any further purification. Yield: 99% (crude) (2.3 g, off white solid). LCMS: (Method A) 117.2 (M-Boc), Rt. 0.6 min, 99.6%

Step 3: tert-butyl 1-(tetrahydro-2H-pyran-4-yl)-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate or tert-butyl 2-(tetrahydro-2H-pyran-4-yl)-2, 4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate

[0341] ##STR00280##

[0342] To the mixture of (tetrahydro-2H-pyran-4-yl)hydrazine hydrochloride (2.3 g, 12.16 mmol) and intermediate 3 (3.08 g, 12.16 mmol) in EtOH (23 mL), K.sub.2CO.sub.3 (8.4 g, 60.82 mmol) was added at RT and the reaction mixture was heated at 80 C. for 6 h. Completion of reaction was monitored by TLC. The reaction mixture was concentrated under vacuum. Water (10 mL) was added and was extracted with EtOAc (225 mL). The combined organic layer was washed with brine solution (10 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 35% EtOAc in pet ether) to afford the title compound. Yield: 14%, (0.51 g, yellow gummy oil). LCMS: (Method A) 308.3 (M+H), Rt. 4.3 min, 96.4%.

Step 4: 1-(tetrahydro-2H-pyran-4-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine hydrochloride or 2-(tetrahydro-2H-pyran-4-yl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine hydrochloride

[0343] ##STR00281##

[0344] To the stirred solution of tert-butyl 1-(tetrahydro-2H-pyran-4-yl)-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate or tert-butyl 2-(tetrahydro-2H-pyran-4-yl)-2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (0.5 g, 1.63 mmol) in dry 1,4-dioxane (2 mL), HCl solution in dioxane (5 mL, 4M) was added dropwise and the reaction mixture was stirred at RT for 1 h. Completion of reaction was monitored by TLC; the reaction mixture was then evaporated under vacuum. The resulting crude material was triturated with EtOAc twice and dried under vacuum to afford the title compound. Yield: 79%, (0.31 g, off white solid). .sup.1H NMR (300 MHz, DMSO-d.sub.6): 7.38 (s, 1H), 4.40-4.38 (m, 1H), 4.06-4.05 (m, 2H), 3.97-3.96 (m, 2H), 3.49-3.46 (m, 2H), 3.38-3.33 (m, 2H), 3.00 (t, J=6.0 Hz, 2H), 2.05-2.04 (m, 2H), 1.78-1.77 (m, 2H). LCMS: (Method A) 208.0 (MBoc+H), Rt. 2.6 min, 96.3%.

Step 5: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(tetrahydro-2H-pyran-4-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine or 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(tetrahydro-2H-pyran-4-yl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0345] ##STR00282##

[0346] To a stirred solution of 1-(tetrahydro-2H-pyran-4-yl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine hydrochloride or 2-(tetrahydro-2H-pyran-4-yl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine hydrochloride (0.3 g, 1.2 mmol) in DMF, TEA (0.51 mL, 3.7 mmol) followed by intermediate 2 (0.34 g, 1.8 mmol) were added at RT and the reaction mixture was heated at 75 C. overnight. Completion of reaction was monitored by TLC. The reaction mixture was concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 2% methanol in DCM). The resulting product was further purified by Prep-HPLC (Method B) to afford the title compound. Yield: 8% (32 mg, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.16-7.14 (m, 2H), 6.43 (d, J=8.4vHz, 1H), 6.74 (s, 1H), 4.50 (t, J=8.8 Hz, 2H), 4.22-4.16 (m, 1H), 3.95-3.93 (m, 2H), 3.54-3.53 (m, 4H), 3.28-3.24 (m, 1H), 3.14 (t, J=8.8 Hz, 2H), 2.72-2.71 (m, 4H), 2.01-1.97 (m, 2H), 1.77-1.74 (m, 2H), 1.31 (d, J=6.8 Hz, 3H). LCMS: (Method A) 354.0 (M+H), Rt. 2.4 min, 99.6% (Max). HPLC: (Method A) Rt 2.4 min, 99.2% (Max).

Example 16: 4-(5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridin-1-yl)tetrahydro-2H-thiopyran 1,1-dioxide or 4-(5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridin-2-yl)tetrahydro-2H-thiopyran 1,1-dioxide

[0347] ##STR00283##

Step 1: tert-butyl ((tetrahydro-4H-thiopyran-4-ylidene)amino)glycinate

[0348] ##STR00284##

[0349] To a stirred solution of tetrahydro-4H-thiopyran-4-one (5 g, 43.09 mmol) in methanol (50 mL), tert-butyl hydrazinecarboxylate (6.20 g, 46.97 mmol) was added at RT and the reaction mixture was stirred overnight at same temperature. Completion of the reaction was monitored by TLC. The reaction mixture was evaporated under vacuum. To the resulting mixture, water (5 mL) was added and was extracted with EtOAc (225 mL). The combined organic layer was washed with brine solution (20 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was used in the next step as such without any further purification. Yield: 96% (9.5 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.68 (s, 1H), 2.75 (t, J=8.1 Hz, 2H), 2.72 (t, J=7.5 Hz, 2H), 2.67 (t, J=6.0 Hz, 2H), 2.65 (t, J=7.4 Hz, 2H), 1.43 (s, 9H). LCMS: (Method A) 175.1 (M-t-Bu+H), Rt. 2.1 min, 35.3% (Max).

Step 2: tert-butyl 2-(tetrahydro-2H-thiopyran-4-yl)hydrazine-1-carboxylate

[0350] ##STR00285##

[0351] To a stirred solution of step 1 tert-butyl 2-(tetrahydro-4H-thiopyran-4-ylidene)hydrazine-1-carboxylate (9.5 g, 41.02 mmol) in acetic acid (50 mL), NaCNBH.sub.3 (2.85 g, 45.3 mmol) was added at 0 C. and the reaction mixture was stirred for 2 h at RT. After completion of the reaction (monitored by TLC), the reaction mixture was evaporated under vacuum and to the resulting mixture water (15 mL) was added. The aqueous layer was extracted with EtOAc (250 mL). The combined organic layer was dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was used as such in the next step without any further purification. Yield: 83% (7.8 g, colourless liquid). LCMS: (Method A) 177.1 (M-t-Bu+H), Rt. 1.8 min, 96.4% (Max).

Step 3: (tetrahydro-2H-thiopyran-4-yl)hydrazine hydrochloride

[0352] ##STR00286##

[0353] To a stirred solution of tert-butyl 2-(tetrahydro-2H-thiopyran-4-yl)hydrazine-1-carboxylate (7.8 g, 33.62 mmol) in dry 1,4-dioxane (30 mL), HCl solution in dioxane (33.5 mL, 134 mmol, 4M) was added dropwise at 0 C. and the reaction mixture was stirred at RT for 3 h. After completion of the reaction (monitored by TLC), the reaction mixture was evaporated under vacuum. The resulting crude material was triturated with EtOAc, hexane and diethyl ether to afford the title compound which was used in the next step without any further purification. Yield: 91% (4 g, off white solid). LCMS: (Method A) 133.3 (M-t-Bu+H), Rt. 0.7 min, 99.5% (Max).

Step 4: tert-butyl 1-(tetrahydro-2H-thiopyran-4-yl)-1,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate or tert-butyl 2-(tetrahydro-2H-thiopyran-4-yl)-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate

[0354] ##STR00287##

[0355] To a stirred solution of intermediate 3 (3 g, 11.8 mmol) in DMF (20 mL), TEA (4.97 mL, 35.4 mmol) and (tetrahydro-2H-thiopyran-4-yl)hydrazine hydrochloride (1.87 g, 14.19 mmol) were added at RT and the reaction mixture was heated at 80 C. for 8 h. Completion of the reaction was monitored by TLC. The reaction mixture was evaporated under vacuum. To the resulting mixture, water (5 mL) was added and was extracted with EtOAc (250 mL). The combined organic layer was washed with brine solution (20 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 60-70% EtOAc in hexane) to afford the title compound. Yield: 85% (3.2 g, yellow gummy oil). LCMS: (Method B) 324.2 (M+H), Rt. 5.8 min, 87.4% (Max). HPLC: (Method B), Rt. 4.9 min, 80.1% (Max).

Step 5: tert-butyl 1-(1,1-dioxidotetrahydro-2H-thiopyran-4-yl)-1,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate or tert-butyl 2-(1,1-dioxidotetrahydro-2H-thiopyran-4-yl)-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate

[0356] ##STR00288##

[0357] To a stirred solution of tert-butyl 1-(tetrahydro-2H-thiopyran-4-yl)-1,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate or tert-butyl 2-(tetrahydro-2H-thiopyran-4-yl)-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate (3.1 g, 9.58 mmol) in DCM (30 mL), m-CPBA (4.13 g, 23.95 mmol) was added at 0 C. batchwise and the reaction mixture was stirred at RT for 3 h. After completion of the reaction (monitored by TLC), the reaction mixture was evaporated under vacuum. To the resulting mixture, water (5 mL) was added and was extracted with EtOAc (250 mL). The combined organic layer was washed with brine solution (20 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 80-90% EtOAc in hexane) to afford the title compound. Yield: 83% (2.8 g, yellow gummy oil). LCMS: (Method A) 356.1 (M+H), Rt. 2.4 min, 46.2% (Max).

Step 6: 4-(4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridin-1-yl)tetrahydro-2H-thiopyran 1,1-dioxide hydrochloride or 4-(4,5,6,7-tetrahydro-2H-pyrazolo[3,4-c]pyridin-2-yl)tetrahydro-2H-thiopyran 1,1-dioxide hydrochloride

[0358] ##STR00289##

[0359] To a stirred solution of tert-butyl 1-(1,1-dioxidotetrahydro-2H-thiopyran-4-yl)-1,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate or tert-butyl 2-(1,1-dioxidotetrahydro-2H-thiopyran-4-yl)-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-c]pyridine-6-carboxylate (2.7 g, 7.59 mmol) in dry 1,4-dioxane (20 mL) at 0 C., HCl solution in dioxane (13.5 mL, 30.36 mmol, 4M) was added dropwise and the reaction mixture was stirred at RT for 3 h. After completion of the reaction (monitored by TLC), the reaction mixture was evaporated under vacuum and the resulting crude material was triturated with EtOAc, hexane and diethyl ether to afford the title compound. Yield: 94% (1.8 g, yellow solid). LCMS: (Method B) 256.1 (M+H), Rt. 0.7 min, 49.9% (Max).

Step 7: 4-(5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridin-1-yl)tetrahydro-2H-thiopyran 1,1-dioxide or 4-(5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridin-2-yl)tetrahydro-2H-thiopyran 1, 1-dioxide

[0360] ##STR00290##

[0361] To a stirred solution of 4-(4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridin-1-yl)tetrahydro-2H-thiopyran 1,1-dioxide hydrochloride or 4-(4,5,6,7-tetrahydro-2H-pyrazolo[3,4-c]pyridin-2-yl)tetrahydro-2H-thiopyran 1,1-dioxide hydrochloride (200 mg, 0.78 mmol) in DMF (10 mL), intermediate 2 (171 mg, 0.93 mmol) followed by TEA (0.3 mL, 2.34 mmol) were added at RT and the reaction mixture was heated at 80 C. overnight. Completion of the reaction was monitored by TLC. The reaction mixture was then evaporated under vacuum. To the resulting mixture, water (5 mL) was added and the aqueous layer was extracted with EtOAc (250 mL). The combined organic layer was washed with brine solution (20 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by prep.HPLC (method B) to afford the title compound. Yield: 12% (34.76 mg, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 7.21 (s, 1H), 7.15 (d, J=7.4 Hz, 1H), 6.79 (d, J=7.2 Hz, 1H), 6.74 (s, 1H), 4.52-4.45 (m, 3H), 3.55-3.49 (m, 2H), 3.41-3.35 (m, 2H), 3.28-3.12 (m, 5H), 2.72-2.60 (m, 4H), 2.42-2.37 (m, 2H), 2.16-2.13 (m, 2H), 1.31 (d, J=4.4 Hz, 3H). LCMS: (Method A) 402.0 (M+H), Rt. 2.3 min, 97.6% (Max). HPLC: (Method A), Rt. 2.3 min, 97.9% (Max).

Example 17: 7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(4-(methylsulfonyl)phenyl)-5,6,7,8-tetrahydro-[1,2,4triazolo 1,5-a]pyrazine

[0362] ##STR00291##

Step 1: [1,2, 4]triazolo[1, 5-a]pyrazin-2-amine

[0363] ##STR00292##

[0364] To a solution of 2-amino pyrazine (15.0 g, 157.7 mmol) in dry 1,4-dioxane (150 mL), 1-ethoxycarbonylisothiocyanate (20.7 g, 173.5 mmol) was added at 0 C. and the reaction mixture was stirred at RT for 2 h. After the completion of reaction (monitored by TLC), the reaction mixture was concentrated under vacuum and the resulting material was dissolved in dry methanol (150 mL). To the stirred solution, hydroxylamine hydrochloride (32.87 g, 473.1 mmol) and TEA (106 mL, 788.5 mmol) were added and the reaction mixture was stirred for 2 h at RT, then heated at 80 C. for 3 h. Completion of reaction was monitored by TLC and the reaction mixture was then concentrated under vacuum. To the resulting mixture, water (100 mL) was added and the aqueous layer was extracted with DCM (3100 mL). The combined organic layer was washed with brine solution (100 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum to afford the title compound. Yield: 71% (15 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.84 (s, 1H), 8.70 (d, J=4.3 Hz, 1H), 7.99 (d, J=4.3 Hz, 1H), 6.48 (s, 2H). LCMS: (Method B) 136.2 (M+H), Rt. 1.14 min, 99.5% (Max).

Step 2: 2-bromo-[1,2,4]triazolo[1,5-a]pyrazine

[0365] ##STR00293##

[0366] To a solution of tert-butyl nitrite (25.1 g, 244.17 mmol) in dry MeCN (150 mL), copper (II) bromide (37.12 g, 166.47 mmol) was added and heated to 60 C. for 30 min. The reaction mixture was then cooled to RT and stirred for 5 min. Then [1,2,4]triazolo[1,5-a]pyrazin-2-amine (15 g, 110.98 mmol) was added portionwise and the reaction mixture was stirred for 1 h at 60 C. After completion of the reaction (monitored by TLC), the reaction mixture was filtered through celite and washed with DCM (2100 mL). The combined organic layer was washed with saturated NaHCO.sub.3 (1100 mL), brine solution (100 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 45% EtOAc in pet ether) to afford the title compound. Yield: 10% (2.1 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.40 (s, 1H), 9.11 (d, J=6.0 Hz, 1H), 8.34 (d, J=6.0 Hz, 1H).

Step 3: 2-bromo-5,6,7,8-tetrahydro-[1,2, 4]triazolo[1, 5-a]pyrazine

[0367] ##STR00294##

[0368] To a stirred solution of 2-bromo-[1,2,4]triazolo[1,5-a]pyrazine (2.1 g, 10.71 mmol) in a mixture of dry THF (3 mL) and methanol (1 mL), lithium borohydride solution (2M, 21.43 mL, 21.4 mmol) was added at 0 C. and the reaction mixture was heated at 50 C. for 30 min. After completion of the reaction (monitored by TLC), the reaction mixture was cooled to 0 C. and quenched with saturated NH.sub.4Cl (20 mL). The aqueous layer was extracted with DCM (225 mL), then the combined organic layer was washed with brine solution (50 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum to afford the title product. Yield: 41% (0.86 g, pale brown solid). LCMS: (Method A, ELSD) 203.0 (M+1), Rt. 0.7 min, 99.4% (Max).

Step 4: 2-bromo-7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazine

[0369] ##STR00295##

[0370] To a 0 C. solution of 1-(2,3-dihydrobenzofuran-6-yl)ethan-1-ol (2 g, 12.1 mmol) in dry DCM (20 mL), thionyl chloride (2.72 mL, 24.3 mmol) was added and stirred at RT for 2 h. After the completion of reaction (monitored by TLC), the reaction mixture was concentrated completely and added over a reaction mixture of 2-bromo-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazine (0.85 g, 4.20 mmol) and TEA (1.7 mL, 12.6 mmol) in dry MeCN (15 mL). The reaction mixture was heated at 60 C. overnight. Completion of reaction was monitored by TLC, then the reaction mixture was concentrated under vacuum. To the resulting mixture, water (15 mL) was added and the aqueous layer was extracted with DCM (215 mL). The combined organic layer was washed with brine solution (15 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 5% methanol in DCM) to afford the title compound. Yield: 6% (0.17 g, brown gummy solid). LCMS: (Method A) 351.0 (M+H), Rt. 2.5 min, 59.3% (Max).

Step 5: 7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(4-(methylsulfonyl)phenyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1, 5-a]pyrazine

[0371] ##STR00296##

[0372] To a degassed solution of 2-bromo-7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazine (0.17 g, 0.48 mmol) in 1,4-dioxane and water (8:2, 6 mL), 4-methylsulphonylphenylboronic acid pinacol ester (0.21 g, 0.73 mmol), Cs.sub.2CO.sub.3 (0.47 g, 1.46 mmol) and Pd(PPh.sub.3).sub.4 (5.6 mg, 0.05 mmol) were added and the reaction mixture was heated at 80 C. for 6 h. Completion of reaction was monitored by TLC, then the reaction mixture was concentrated under vacuum. To the resulting mixture, water (8 mL) was added and the aqueous layer was extracted with DCM (28 mL). The combined organic layer was washed with brine solution (8 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 50-60% EtOAc in pet ether), then the obtained material was further purified by prep HPLC (Method B) to afford the title compound. Yield: 3% (5.5 mg, white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.20 (d, J=8.8 Hz, 2H), 8.01 (d, J=8.4 Hz, 2H), 7.21 (d, J=7.6 Hz, 1H), 6.85 (d, J=7.6 Hz, 1H), 6.80 (s, 1H), 4.53 (t, J=8.4 Hz, 2H), 4.19-4.14 (m, 2H), 3.91-3.87 (m, 1H), 3.74-3.68 (m, 2H), 3.26 (s, 3H), 3.16 (t, J=8.4 Hz, 2H), 3.00-2.90 (m, 2H), 1.40 (d, J=6.8 Hz, 3H). LCMS: (Method A) 425.0 (M+H), Rt. 2.8 min, 99.4% (Max). HPLC: (Method A) Rt. 2.7 min, 99.9% (Max).

Example 18: 7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(pyridin-3-yl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazine

[0373] ##STR00297##

[0374] To a degassed solution of 2-bromo-7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazine (0.08 g, 0.22 mmol, synthesis described in example 17, steps 1 to 4), Cs.sub.2CO.sub.3 (0.224 g, 0.68 mmol) and pyridine 3-boronic acid pinacol ester (0.07 g, 0.34 mmol) in 1,4-dioxane (2 ml) and water (0.08 ml), Pd(PPh.sub.3).sub.4 (0.013 g, 0.011 mmol) was added and the resulting solution was purged with argon for another 2 min. The reaction mixture was heated at 80 C. overnight. After completion of the reaction (monitored by TLC), the reaction mixture was cooled to RT, quenched with water (5 mL) and the aqueous layer was extracted with EtOAc (210 mL). The combined organic layer was washed with brine solution (20 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by Prep HPLC (method B) to afford the title compound. Yield: 21% (16.74 mg, brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.13 (s, 1H), 8.61 (d, J=4.8 Hz, 1H), 8.27 (d, J=8.0 Hz, 1H), 7.51-7.50 (m, 1H), 7.21 (d, J=7.2 Hz, 1H), 6.85 (d, J=7.6 Hz, 1H), 6.80 (s, 1H), 4.53 (t, J=8.4 Hz, 2H), 4.15-4.14 (m, 2H), 3.86-3.82 (m, 1H), 3.71-3.70 (m, 2H), 3.16-3.14 (m, 2H), 3.08 (m, 3H), 1.40 (d, J=6.8 Hz, 2H). LCMS: (Method A) 348.2 (M+H), Rt. 2.0 min, 94.7% (Max). HPLC: (Method A): Rt. 2.1 min, 94.3% (Max).

Example 19: 6-((7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)amino)nicotinonitrile

[0375] ##STR00298##

Step 1: N-([1,2,4]triazolo[1,5-a]pyrazin-2-yl)acetamide

[0376] ##STR00299##

[0377] To a stirred solution of [1,2,4]triazolo[1,5-a]pyrazin-2-amine (5 g, 0.04 mol, synthesis described in example 17, step 1) in toluene (100 mL), acetic anhydride (7.55 g, 74 mmol) was added at RT and the reaction mixture was heated to reflux overnight. Completion of the reaction was monitored by TLC, then the reaction mixture was filtered and dried under vacuum to afford the title compound. Yield: 55% (3.6 g, white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 11.07 (s, 1H), 9.21 (d, J=6.4 Hz, 1H), 9.01-8.99 (m, 1H), 8.20 (d, J=6.0 Hz, 1H), 2.17 (s, 3H). LCMS: (Method A) 178.2 (M+H), Rt. 0.7 min, 98.7% (Max).

Step 2: N-(5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)acetamide

[0378] ##STR00300##

[0379] To a stirred solution of N-(5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)acetamide (3 g, 16.94 mmol) in ethanol (60 mL), PtO.sub.2 (0.6 g, 2.6 mmol) was added under H.sub.2 ballon pressure at RT and continued for 2 h. Completion of the reaction was monitored by TLC, then the reaction mixture was filtered through celite bed, washed with ethanol (120 mL) and dried under vacuum to afford the title compound. Yield: 75% (2.3 g, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 10.19 (s, 1H), 3.92 (t, J=7.2 Hz, 2H), 3.84 (s, 2H), 3.11 (t, J=7.2 Hz, 2H), 2.01 (s, 3H). LCMS: (Method A) 181.1 (M+H), Rt. 0.5 min, 99.8% (Max).

Step 3: N-(7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)acetamide

[0380] ##STR00301##

[0381] To a stirred solution of N-(5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)acetamide (1.7 g, 9.38 mmol) in MeCN (68 mL), intermediate 2 (2.56 g, 14.07 mmol) and TEA (5.68 g, 56.29 mmol) were added at RT and the reaction mixture was heated at 60 C. for 6 h. Completion of the reaction was monitored by TLC, then the reaction mixture was concentrated under vacuum. To the resulting mixture, water (100 mL) was added and the aqueous layer was extracted with DCM (350 mL). The combined organic layer was washed with brine solution (50 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 4% methanol in DCM) to afford the title compound. Yield: 24% (740 mg, off white solid). LCMS: (Method A) 328.2 (M+H), Rt. 1.7 min, 74.3% (Max).

Step 4: 7-(1-(2, 3-dihydrobenzofuran-6-yl)ethyl)-5, 6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-amine

[0382] ##STR00302##

[0383] To a stirred solution of N-(7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)acetamide (0.74 g, 2.26 mmol) in methanol (14 mL), 6N NaOH (0.36 g, 9.04 mmol) was added and the reaction mixture was stirred at RT overnight. Completion of the reaction was monitored by TLC. The reaction mixture was concentrated under vacuum. The resulting crude material was suspended in water (20 mL) and was neutralized with 2N HCl to adjust pH6.0. The aqueous layer was extracted with 20% methanol in DCM (350 mL). The combined organic layer was washed with brine solution (50 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum to afford the title compound. Yield: 56% (360 mg, off white solid). LCMS: (Method A) 286.2 (M+H), Rt. 1.6 min, 64.2% (Max).

Step 5: 6-((7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)amino)nicotinonitrile

[0384] ##STR00303##

[0385] To a stirred solution of 7-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[1,5-a]pyrazin-2-amine (0.18 g, 0.63 mmol) in DMF (14 mL) at 0 C., 60% NaH (0.04 g, 0.95 mmol) was added and stirred for 15 min. Then 6-chloronicotinonitrile (0.13 g, 0.95 mmol) was added and the reaction mixture was heated at 70 C. overnight. Completion of the reaction was monitored by TLC, then the reaction mixture was cooled to RT and quenched with water (10 mL). The obtained solid was filtered, dried under vacuum and the resulting material was neutralized with 2N HCl to adjust pH6.0. The resulting crude material was suspended in water (20 mL) and the aqueous layer was extracted with 20% methanol in DCM (350 mL). The combined organic layer was washed with brine solution (50 mL), dried over anhydrous Na.sub.2SO.sub.4, filtered and concentrated under vacuum. The resulting crude material was further purified by Prep HPLC (Method B) to afford the title compound.

[0386] Yield: 18% (21.08 mg, off white solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 10.49 (s, 1H), 8.59 (d, J=1.6 Hz, 1H), 8.07 (dd, J=8.8, 1.2 Hz, 1H) 7.90 (d, J=8.8 Hz, 1H), 7.18 (d, J=7.2 Hz, 1H), 6.82 (d, J=7.5 Hz, 1H), 6.78 (s, 1H), 4.54-4.50 (m, 2H), 4.01-3.99 (m, 2H), 3.79-3.75 (m, 1H), 3.67 (q, J=7.5 Hz, 1H), 3.55 (d, J=7.5 Hz, 1H), 3.18-3.15 (m, 2H), 2.93-3.86 (m, 2H), 1.36 (d, J=7.5 Hz, 3H). LCMS: (Method B) 388.1 (M+H), Rt. 2.4 min, 97.3% (Max). HPLC: (Method B): Rt. 2.6 min, 98.9% (Max).

Example 20: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-2-(pyrimidin-2-ylmethyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0387] ##STR00304##

Step 1: tert-butyl 2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate

[0388] ##STR00305##

[0389] To a stirred solution of intermediate 3 (25 g, 98.42 mmol) in EtOH (500 mL), K.sub.2CO.sub.3 (27.16 g, 196.8 mmol) and hydrazinehydrate (39.41 g, 787.40 mmol) were added and the reaction mixture was refluxed at 78 C. overnight. Completion of the reaction was monitored by TLC, then the reaction mixture was evaporated under vacuum. To the resulting mixture, water (200 mL) was added and the aqueous layer was extracted with EtOAc (2300 mL). The combined organic layer was washed with brine solution (50 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by column chromatography (Biotage Isolera, eluent: 70% EtOAc in hexane). Yield: 77% (17 g, off white Solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 12.50 (s, 1H), 7.42 (s, 1H), 4.36 (s, 2H), 3.58 (t, J=6.4 Hz, 2H), 2.62 (t, J=6.4 Hz, 2H), 1.41 (s, 9H). LCMS: (Method A) 224.0 (M+H), Rt. 1.9 min, 93.4% (Max).

Step 2: tert-butyl 2-(pyrimidin-2-ylmethyl)-2, 4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate or tert-butyl 1-(pyrimidin-2-ylmethyl)-1,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate

[0390] ##STR00306##

[0391] To a stirred solution of tert-butyl 2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (1.5 g, 6.72 mmol) in THF (30 mL) at 0 C., NaH (60%) (0.23 g, 10.08 mmol) was added and stirred for 15 min. Then 2-2-(chloromethyl)pyrimidine (0.94 g, 7.39 mmol) was added to the reaction mixture and stirred at RT for 4 h. Completion of the reaction was monitored by TLC, then the reaction mixture was quenched with ice cold water (20 mL) and the aqueous layer was extracted with EtOAc (2200 mL). The combined organic layer was washed with brine solution (10 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by flash chromatography (Biotage Isolera, eluent: 20% EtOAc in hexane) and the regioisomers were separated by SFC (method B) to afford the title compound. The structure of both isomers has been confirmed by NOESY.

[0392] Isomer 1: Yield: 19% (400 mg, brown gummy oil). .sup.1H NMR (400 MHz, CDCl.sub.3): 8.76 (d, J=5.2 Hz, 2H), 7.40 (s, 1H), 7.27 (t, J=8.0 Hz, 1H), 5.60 (s, 2H), 4.53 (s, 2H), 3.73 (s, 2H), 2.84 (t, J=5.6 Hz, 2H), 1.52-1.50 (m, 9H). LCMS: (Method A), 316.3 (M+H), Rt. 2.2 min, 99.1% (Max). HPLC: (Method A), Rt. 3.1 min, 99.8% (Max).

[0393] Isomer 2: Yield: 33% (700 mg, brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.77 (d, J=6.4 Hz, 2H), 7.43 (t, J=6.4 Hz, 1H), 7.27 (s, 1H), 5.44 (s, 2H), 4.35 (s, 2H), 3.60 (t, J=7.2 Hz, 2H), 2.66-2.62 (m, 2H), 1.42-1.40 (m, 9H). LCMS: (Method A), 316.3 (M+H), Rt. 2.3 min, 91.5% (Max).

[0394] HPLC: (Method A), Rt. 3.1 min, 94.3% (Max).

Step 3: 2-(pyrimidin-2-ylmethyl)-4, 5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0395] ##STR00307##

[0396] To a stirred solution of tert-butyl 2-(pyrimidin-2-ylmethyl)-2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (Isomer 1 obtained in step 2, 400 mg, 26.66 mmol) in dry 1, 4-dioxane (10 mL) at 0 C., HCl solution in dioxane (13.33 mL, 4M) was added dropwise and the reaction mixture was stirred at RT for 3 h. After completion of the reaction (monitored by TLC), the reaction mixture was evaporated under vacuum. The resulting crude material was triturated with EtOAc, hexane and diethyl ether to afford the title compound which was forwarded to the next step as such without any further purification. Yield: 49% (150 mg, pale yellow solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.28 (s, 1H), 8.78 (d, J=1.2 Hz, 2H), 7.77 (s, 1H), 7.46-7.45 (m, 1H), 5.50 (s, 2H), 4.15 (d, J=2.8 Hz, 2H), 3.35 (s, 2H), 2.83 (t, J=6.0 Hz, 2H).

Step 4: 5-(1-(2, 3-dihydrobenzofuran-6-yl)ethyl)-2-(pyrimidin-2-ylmethyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine

[0397] ##STR00308##

[0398] To a stirred solution of 2-(pyrimidin-2-ylmethyl)-4,5,6,7-tetrahydro-2H-pyrazolo[4,3-c]pyridine (150 mg, 0.697 mmol) in MeCN (10 mL), intermediate 2 (253 mg, 1.39 mmol) followed by TEA (0.4 mL, 2.79 mmol) were added and the reaction mixture was heated at 60 C. overnight. Completion of the reaction was monitored by TLC, then the reaction mixture was evaporated under vacuum. To the resulting mixture, water (10 mL) was added and the aqueous layer was extracted with EtOAc (250 mL). The combined organic layer was washed with brine solution (10 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by Prep HPLC (Method B) to afford the title compound. Yield: 2% (2.86 mg, pale brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.78 (d, J=4.8 Hz, 2H), 7.49 (s, 1H), 7.44 (t, J=4.8 Hz, 1H), 7.16 (d, J=7.6 Hz, 1H), 6.80 (d, J=7.6 Hz, 1H), 6.74 (s, 1H), 5.41 (s, 2H), 4.51 (t, J=8.8 Hz, 2H), 3.55-3.52 (m, 2H), 3.34-3.32 (m, 2H), 3.14 (t, J=8.8 Hz, 2H), 2.71 (s, 1H), 2.62-2.51 (m, 2H), 1.32 (d, J=6.4 Hz, 3H). LCMS: (Method A) 362.2 (M+H), Rt. 2.1 min, 95.2% (Max). HPLC: (Method A) Rt. 2.2 min, 97.1% (Max).

Example 21: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(pyrimidin-2-ylmethyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0399] ##STR00309##

Step 1: 1-(pyrimidin-2-ylmethyl)-4,5, 6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0400] ##STR00310##

[0401] To a stirred solution of tert-butyl 2-(pyrimidin-2-ylmethyl)-2,4,6,7-tetrahydro-5H-pyrazolo[4,3-c]pyridine-5-carboxylate (Isomer 2 obtained in Example 20, step 2, 400 mg, 26.66 mmol, isomer 2) in dry 1, 4-dioxane (10 mL) at 0 C., HCl-dioxane (13.33 mL, 4M) was added dropwise and the reaction mixture was stirred at RT for 3 h. After completion of the reaction (monitored by TLC), the reaction mixture was evaporated under vacuum. The resulting crude material was triturated with EtOAc, hexane and diethyl ether to afford the title compound which was used in the next step as such without any further purification. Yield: 75% (420 mg, pale yellow solid). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 9.28 (s, 2H), 8.79 (t, J=5.6 Hz, 1H), 7.48-7.37 (m, 1H), 5.51-5.27 (m, 5H), 4.13 (s, 1H), 3.58-3.57 (m, 2H), 2.97 (d, J=6.4 Hz, 1H). LCMS: (Method A), 216.0 (M+H), Rt. 0.6 min, 97.6% (Max).

Step 2: 5-(1-(2,3-dihydrobenzofuran-6-yl)ethyl)-1-(pyrimidin-2-ylmethyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine

[0402] ##STR00311##

[0403] To a stirred solution of 1-(pyrimidin-2-ylmethyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine (150 mg, 0.69 mmol) in MeCN (10 mL), intermediate 2 (253 mg, 1.39 mmol) followed by TEA (0.4 mL, 2.79 mmol) were added and the reaction mixture was heated at 60 C. overnight. Completion of the reaction was monitored by TLC, then the reaction mixture was evaporated under vacuum. To the resulting mixture, water (10 mL) was added and the aqueous layer was extracted with EtOAc (250 mL). The combined organic layer was washed with brine solution (10 mL), dried over anhydrous Na.sub.2SO.sub.4 and concentrated under vacuum. The resulting crude material was purified by Prep HPLC (Method B) to afford the title compound. Yield: 5% (16.4 mg, light brown gummy oil). .sup.1H NMR (400 MHz, DMSO-d.sub.6): 8.77 (d, J=5.2 Hz, 2H), 7.43 (t, J=4.8 Hz, 1H), 7.16-7.7.14 (m, 2H), 6.79 (dd, J=7.2, 1.2 Hz, 1H), 6.73 (s, 1H), 5.38 (s, 2H), 4.51 (t, J=8.8 Hz, 2H), 3.56-3.52 (q, J=6.8 Hz, 3H), 3.14 (t, J=8.8 Hz, 2H), 2.60-2.57 (m, 1H), 2.56-2.52 (m, 3H), 1.32 (d, J=6.8 Hz, 3H). LCMS: (Method A) 362.2 (M+H), Rt. 2.1 min, 98.2% (Max). HPLC: (Method A) Rt. 2.2 min, 97.9% (Max).

Example B01: Human O-GlcNAcase Enzyme Inhibition Assay

[0404] 5 l of the appropriate concentration of a solution of inhibitor in McIlvaine's Buffer (pH 6.5) in 2% DMSO (for a dose response curve calculation) is added into each well of a 384-well plate (Greiner, 781900). Then, 20 nM of His-Tagged hOGA and 10 M of FL-GlcNAc (Fluorescein mono-beta-D-(2-deoxy-2-N-acetyl) glucopyranoside; Marker Gene Technologies Inc, M1485) were added to the 384-well plate for a final volume of 20 l. After incubation for 60 min at room temperature, the reaction was terminated by the addition of 10 L of stop buffer (200 mM glycine, pH 10.75). The level of fluorescence (.sub.exc 485 nm; (.sub.emm 520 nm) was read on a PHERAstar machine. The amount of fluorescence measured was plotted against the concentration of inhibitor to produce a sigmoidal dose response curve to calculate an IC.sub.50. All individual data was corrected by subtraction of the background (Thiamet 3 uM=100% inhibition) whilst 0.5% DMSO was considered as the control value (no inhibition).

Example B02: Pharmacodynamic Model: Total Protein O-GlcNAcylation Immunoassay (RL2 mAb, Meso Scale Electrochemiluminescence (ECL) Assay)

[0405] The test compound was administered orally to C57BL/6J mice. At defined time intervals after compound administration, typically a time ranging between 2 and 48 hours, preferably between 4 and 24 hours, mice were sacrificed by decapitation for blood collection and forebrain dissection. Right brain hemispheres were placed in 2 ml Precellys tubes, snap frozen in dry ice and stored at 80 C. Left hemispheres were placed in 2 ml Eppendorf tubes, snap frozen in dry ice and stored at 80 C. until further processing. Blood samples were collected in Sarstedt tubes containing 35 IU of Heparin and kept at 4 C. After centrifugation for 10 min at 3800g, 4 C., 50 L of plasma from each sample was transferred to a 1.5 ml Eppendorf tube and stored at 80 C.

[0406] For the preparation of soluble brain protein for the immunoassay the hemispheres were homogenized in ice-cold Cytobuster reagent (71009-Merck Millipore) buffer with protease inhibitor cocktail. After centrifugation for 15 min at 17000g at 4 C. the supernatants were transferred into polycarbonate tubes (1 ml). The supernatants were cleared by centrifugation for 1 h. at 100000g, 4 C., and the protein concentrations were determined by using the BCA kit (23227-Pierce, Rockford, Ill.) according to the manufacturer's instructions.

Total Protein O-GlcNAcylation Immunoassay:

[0407] Samples were randomised and 120 g/ml (25 l/well) of soluble brain protein was directly coated on a Multi-array 96-well high bind plate (L15XB-3 High bindMeso Scale Discovery) overnight at 4 C. After washing (3 with PBS-T buffer), the plate was blocked with MSD blocker A solution for 1 h. at room temperature (RT) under agitation. After washing (3 with PBS-T buffer), the plate was incubated with 0.1 g/ml of a mouse monoclonal antibody directed against O-GlcNAc moieties (RL2; MA1-072-Thermo Scientific) for 1 h. at RT under agitation. For the ECL assay, after washing (3 with PBS-T buffer), 1 g/ml of a SULFO-TAG labeled anti-mouse secondary antibody (Meso Scale Discovery) was added and the plate was incubated for 1 h. at RT under agitation and protected from light. After washing (3 with PBS-T buffer), 150 l/well of 1 Read Buffer T was added to the plates before reading on a Sector Imager 6000 (Meso Scale Discovery).

Example B03: Pharmaceutical Preparations

[0408] (A) Injection vials: A solution of 100 g of an active ingredient according to the invention and 5 g of disodium hydrogen phosphate in 3 l of bi-distilled water was adjusted to pH 6.5 using 2 N hydrochloric acid, sterile filtered, transferred into injection vials, lyophilized under sterile conditions and sealed under sterile conditions. Each injection vial contained 5 mg of active ingredient.
(B) Suppositories: A mixture of 20 g of an active ingredient according to the invention was melted with 100 g of soy lecithin and 1400 g of cocoa butter, poured into moulds and allowed to cool. Each suppository contained 20 mg of active ingredient.
(C) Solution: A solution was prepared from 1 g of an active ingredient according to the invention, 9.38 g of NaH.sub.2PO.sub.4.2H.sub.2O, 28.48 g of Na.sub.2HPO.sub.4.12H.sub.2O and 0.1 g of benzalkonium chloride in 940 ml of bi-distilled water. The pH was adjusted to 6.8, and the solution was made up to 1 l and sterilized by irradiation. This solution could be used in the form of eye drops.
(D) Ointment: 500 mg of an active ingredient according to the invention were mixed with 99.5 g of Vaseline under aseptic conditions.
(E) Tablets: A mixture of 1 kg of an active ingredient according to the invention, 4 kg of lactose, 1.2 kg of potato starch, 0.2 kg of talc and 0.1 kg of magnesium stearate was pressed to give tablets in a conventional manner in such a way that each tablet contained 10 mg of active ingredient.
(F) Coated tablets: Tablets were pressed analogously to EXAMPLE E and subsequently coated in a conventional manner with a coating of sucrose, potato starch, talc, tragacanth and dye.
(G) Capsules: 2 kg of an active ingredient according to the invention were introduced into hard gelatin capsules in a conventional manner in such a way that each capsule contained 20 mg of the active ingredient.
(H) Ampoules: A solution of 1 kg of an active ingredient according to the invention in 60 l of bi-distilled water was sterile filtered, transferred into ampoules, lyophilized under sterile conditions and sealed under sterile conditions. Each ampoule contained 10 mg of active ingredient.
(I) Inhalation spray: 14 g of an active ingredient according to the invention were dissolved in 10 l of isotonic NaCl solution, and the solution was transferred into commercially available spray containers with a pump mechanism. The solution could be sprayed into the mouth or nose. One spray shot (about 0.1 ml) corresponded to a dose of about 0.14 mg.

Example B04: Protein Binding in Mice Plasma Using Rapid Equilibrium Dialysis

Materials

[0409] CD1 Mice Plasma: pooled male, K2-EDTA (MSEPLEDTA2, Bioreclammation, USA [0410] Phosphate Buffered Saline (1PBS), pH 7.4, 100 mM (Sigma, Cat No. P4417) [0411] RED inserts (Pierce, Cat No. 9006, 8 kDa MWCO) [0412] Sample Analysis: LC-MS/MS

Methods

[0413] Preparation of DMSO Stock Solution

[0414] From 20 mM DMSO stock solutions of reference and test compounds, 1 mM DMSO intermediate working solutions are prepared. From 1 mM intermediate working solutions, 100 M DMSO working solutions are prepared.

[0415] Sample Preparation Procedure:

[0416] Selected plasma is brought from 20 C. to 37 C. using water bath before its use. Test solution is prepared by adding the DMSO working solution of the reference or test compound (2 L; 100 M) to the selected plasma (198 L). Spiked plasma (200 l) is transferred to sample compartment of RED insert placed in the teflon plate. 350 l of 1PBS is added in the buffer compartment of RED insert. The teflon plate is covered with sealing mat and agitated at 37 C. for 5 hours at 500 RPM in a Thermomixer. After incubation time, an aliquot of plasma (50 l) from sample compartment is mixed with blank 1PBS (50 l). Similarly, an aliquot of buffer (50 l) from buffer compartment is mixed with blank plasma (50 l). Quenching solution (200 L, acetonitrile containing internal standard tolbutamide (0.5 g/mL)) is added and the resulting solutions are mixed using a vortex mixer and centrifuged (Eppendorf 5415, 13792 g). Supernatants are analyzed using a Mass Spectrometer. The sample (supernatant fraction, 5 L) is injected into the LC-MS/MS instrument.

[0417] Chromatographic Conditions:

LC-MS/MS: API 4000 LC-MS/MS

Software: Analyst Version 1.6.1

Column Phenomenex Synergy 30*4.6*5

Column Oven: 40 C.

Mode: ESI Positive

[0418] Injection volume: 5 l

Flow Rate: 1000 L/mL

[0419] Buffer: 0.1% Formic acid in Water

Method: Isocratic Method/Gradient

[0420] Composition: A) 0.1% Formic acid in Water [0421] B) 0.1% Formic acid in Methanol

TABLE-US-00003 Mobile Mobile Time (Sec) Flow (L) Phase A Phase B 0.01 1000 10 90 0.4 1000 10 90 0.8 1000 90 10 1.5 1000 90 10 1.8 1000 10 90 2.5 1000 10 90

Results Calculation

[0422] After the concentration of free drug and total drug has been determined by LCMS/MS, percent plasma protein binding can be calculated as follows:

[00001] $% .Math. .Math. fraction .Math. .Math. unbound = \frac{Drug .Math. .Math. concentration .Math. .Math. in .Math. .Math. buffer .Math. .Math. after .Math. .Math. 5 .Math. .Math. hours}{Drug .Math. .Math. concentration .Math. .Math. in .Math. .Math. plasma .Math. .Math. after .Math. .Math. 5 .Math. .Math. hours} 100$

Following this protocol, % fraction unbound in plasma from different species can be also measured.

Example B05: Determination of In Vitro Intrinsic Clearance (Cl.SUB.int.-In Vitro) with Mouse, Rat and Human Liver Microsomes

[0423] In this assay, test compounds are incubated with liver microsomes from mouse, rat and human, and rate of disappearance of drug is determined using LC-MS/MS. Conditions used in the assay are summarized below:

Materials

[0424] CD-1 Mice liver microsomes, pooled male (Life Technologies, Cat No. MSMC-PL) (20 mg/ml) [0425] SD Rat liver microsomes, pooled male (Life Technologies, Cat No. RTMCL-PL) (20 mg/ml) [0426] Human liver microsomes, pooled mixed gender (Life Technologies, Cat No. HMMC-PL) (20 mg/ml) [0427] NADPH (SRL Mumbai, Cat No. 99197) [0428] Verapamil (Sigma, Cat No. V4629) [0429] Atenolol (Sigma, Cat No. A7655) [0430] Tolbutamide (Sigma Cat. No. T0891) [0431] Assay buffer: 50 mM potassium phosphate buffer, pH 7.4 [0432] Test & reference compounds: DMSO stock solutions (10 mM concentration) are prepared and stored at room temperature. An intermediate 1 mM solution of test or reference compounds is prepared by mixing 10 L of 10 mM DMSO stock with 90 L of DMSO. The contents are mixed vigorously in a vortex mixer.

Methods

[0433] Preparation of Working Solutions of Test and Reference Compounds:

[0434] Working solution (100 M concentration) is prepared by mixing 10 L of 1 mM DMSO solution of test or reference compounds with 90 L of assay buffer. The mixture is mixed vigorously in a vortex mixer. This resulting solution is containing 10% of DMSO. For the metabolic stability assay, 10 L of this 100 M working solution is added to a final assay volume of 1 mL, yielding final test concentration of 1 M and DMSO concentration of 0.1%.

[0435] Metabolic Stability Assay

[0436] Metabolic stability assay is done in a final volume of 1 ml in 50 mM assay buffer, potassium phosphate buffer, pH 7.4. Assay is carried out in duplicates (n=2). A mixture containing 955 L of assay buffer, 25 L of liver microsomes and 10 L of 100 M test compound solution is pre-incubated for 10 minutes in a water-bath maintained at 37 C. After pre-incubation, reaction is started by adding 10 L of 100 mM NADPH solution. The solution is mixed and incubated at 37 C. in a water-bath. The final concentration of the different components in the assay is: DMSO 0.1%, test compound 1 M, liver microsome protein 0.5 mg/ml and NADPH 1 mM.

[0437] Aliquots (100 L) are taken at various time-points (0, 5, 15, 30 and 45 minutes) and quenched with 100 L of acetonitrile containing tolbutamide (500 ng/mL) as internal standard. Samples are mixed using a vortex mixer and centrifuged at 4000 rpm for 10 minutes (Eppendorf 5810R, 3000 g). The supernatants (5 L) are transferred to 96 well plates and submitted for LC-MS/MS analysis.

[0438] Separate incubations in the same assay mixture, but in the absence of NADPH, are run in parallel as control for compound stability. This control assay is carried out in duplicates (n=2). After pre-incubation, addition of NADPH is omitted and replaced with 10 L of assay buffer. The final assay volume is 1 mL and aliquots (100 L) are withdrawn and processed for analysis as described for metabolic stability assay.

[0439] LC-MS/MS Conditions (Generic Method)

LC-MS/MS: API Sciex 4000 with Nexera UHPLC

Software: Analyst Version 1.6.1

[0440] Column: Phenomenex kinetex C18 503.0 mm, 2.6

Column Oven: 40 C.

Mode: ESI Positive

[0441] Injection volume: 5 l

Flow Rate: 1000 L/mL

[0442] Buffer: 0.1% Formic acid in Water

Method: Isocratic Method/Gradient

[0443] Composition: A) 0.1% Formic acid in Water [0444] B) 0.1% Formic acid in Methanol

TABLE-US-00004 Mobile Mobile Time (Sec) Flow (L) Phase A Phase B 0.01 1000 10 90 0.4 1000 10 90 1 1000 90 10 1.5 1000 90 10 1.8 1000 10 90 3 1000 10 90

Results Calculation

[0445] From LC-MS/MS data, amount of drug remaining at different time points was determined (% PCR). The logarithm of % PCR was plotted against time to get the slope value. From the slope value, in vitro T.sub.1/2 was determined. In vitro intrinsic clearance (Cl.sub.int) was calculated using the following formulae:

[00002] ${CL}_{int} = \frac{0.693}{In .Math. .Math. vitro .Math. .Math. t_{1 / 2}} \frac{Volume .Math. .Math. of .Math. .Math. incubation}{mg .Math. .Math. of .Math. .Math. microsomal .Math. .Math. protein}$ $In .Math. .Math. vitro .Math. .Math. t_{1 / 2} = \frac{0.693}{K_{el}}$

[0446] Where K.sub.el is Elimination Constant (Slope)

[0447] Methods for treating the diseases mentioned in this specification, such as tauopathy, by administering one or more of the compounds of the present invention to a patient in need thereof are also object of this invention.

[0448] If chemical bonds in the structures above are drawn as follows: [0449] custom-character or
they indicate a defined, i.e. R or S, stereochemistry at at least one of the atoms to which they are attached to.

[0450] This is exemplified below, wherein the structure

##STR00312##

is representing only one of the two possible enantiomers,

##STR00313##

i.e. a single individual chemical structure as opposed to a mixture of enantiomers.

ANNULATED GLYCOSIDASE INHIBITORS

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