Halogenated benzoxazines and their use

Abstract

The present invention relates to novel halogenated benzoxazines, methods for their production, their use for the diagnosis of diseases and their use for the production of medicaments for the diagnosis of diseases, preferably dementia diseases and in particular the Alzheimer's disease, in humans and/or animals.

Claims

1. Radioactive tracer of the formula ##STR00028## in which, X and Y independently from one another represent CH, CH.sub.2, N, S or O, wherein X and Y are not simultaneously CH or CH.sub.2, wherein, if X represents CH or N, the dotted line between X and the neighboring atom represents a bond, and wherein, if Y represents CH or N, the dotted line between Y and the neighboring atom represents a bond, R.sub.1 and R.sub.2 independently from one another are selected from the group consisting of (C.sub.1-C.sub.2)-alkyl, (C.sub.1-C.sub.2)-alkoxy and (C.sub.1-C.sub.2)-alkyl sulfonyl, wherein alkyl, alkoxy and alkyl sulfonyl can be substituted with one up to three substituents selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.3, R.sub.4, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 independently from one another are selected from the group consisting of hydrogen, halogen, hydroxy, amino, cyano, nitro, (C.sub.1-C.sub.4)-alkyl, (C.sub.1-C.sub.4)-alkyl amino and (C.sub.1-C.sub.4)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.5, if X represents CH or N, represents a substituent selected from the group consisting of hydrogen, halogen, hydroxy, amino, cyano, nitro, (C.sub.1-C.sub.4)-alkyl, (C.sub.1-C.sub.4)-alkyl amino and (C.sub.1-C.sub.4)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.5, if X represents CH.sub.2, S or O, represents two substituents independently from one another selected from the group consisting of hydrogen, halogen, hydroxy, amino, cyano, nitro, (C.sub.1-C.sub.4)-alkyl, (C.sub.1-C.sub.4)-alkyl amino and (C.sub.1-C.sub.4)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.6, if X represents CH or N, represents a substituent selected from the group consisting of hydrogen, halogen, hydroxy, amino, cyano, nitro, (C1-C.sub.4)-alkyl, (C.sub.1-C.sub.4)-alkyl amino and (C.sub.1-C.sub.4)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.6, if Y represents CH.sub.2, S or O, represents two substituents independently from one another selected from the group consisting of hydrogen, halogen, hydroxy, amino, cyano, nitro, (C.sub.1-C.sub.4)-alkyl, (C.sub.1-C.sub.4)-alkyl amino and (C.sub.1-C.sub.4)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, wherein the radioactive tracer of the formula (I) comprises at least one substituent selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, and the salts thereof, the solvates thereof and the solvates of the salts thereof.

2. Radioactive tracer of claim 1, wherein X and Y independently from one another represent CH, CH.sub.2, N, S or O, wherein X and Y are not simultaneously CH or CH.sub.2, wherein, if X represents CH or N, the dotted line between X and the neighboring atom represents a bond, and wherein, if Y represents CH or N, the dotted line between Y and the neighboring atom represents a bond, R.sub.1 and R.sub.2 independently from one another are selected from the group consisting of (C.sub.1-C.sub.2)-alkyl, (C.sub.1-C.sub.2)-alkoxy and (C.sub.1-C.sub.2)-alkyl sulfonyl, wherein alkyl, alkoxy and alkyl sulfonyl can be substituted with one up to three substituents selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.3, R.sub.4, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 independently from one another are selected from the group consisting of hydrogen, halogen, hydroxy, amino, (C.sub.1-C.sub.2)-alkyl, and (C.sub.1-C.sub.2)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and ad .sup.18F, R.sub.5, if X represents CH or N, represents a substituent selected from the group consisting of hydrogen, halogen, hydroxy, amino, (C.sub.1-C.sub.2)-alkyl, and (C.sub.1-C.sub.2)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.5, if X represents CH.sub.2, S or O, represents two substituents independently from one another selected from the group consisting of hydrogen, halogen, hydroxy, amino, (C.sub.1-C.sub.2)-alkyl, and (C.sub.1-C.sub.2)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.6, if Y represents CH or N, represents a substituent selected from the group consisting of hydrogen, halogen, hydroxy, amino, (C.sub.1-C.sub.2)-alkyl, and (C.sub.1-C.sub.2)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, R.sub.6, if Y represents CH.sub.2, S or O, represents two substituents independently from one another selected from the group consisting of hydrogen, halogen, hydroxy, amino, (C.sub.1-C.sub.2)-alkyl, and (C.sub.1-C.sub.2)-alkoxy, wherein alkyl and alkoxy can be substituted with one up to three substituents selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, wherein the radioactive tracer of the formula (I) comprises at least a substituent selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, and the salts thereof, the solvates thereof and the solvates of the salts thereof.

3. Radioactive tracer of claim 2, wherein X and Y independently from one another represent CH.sub.2, S or O, wherein X and Y are not simultaneously CH.sub.2, R.sub.1 and R.sub.2 are independently from another selected from the group consisting of (C.sub.1-C.sub.2)-alkyl, (C.sub.1-C.sub.2)-alkoxy and (C.sub.1-C.sub.2)-alkyl sulfonyl, wherein at least one of the residues represented by R.sub.1 and R.sub.2 is substituted with at least one substituent selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.19F, and R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 represent hydrogen, and the salts thereof, the solvates thereof and the solvates of the salts thereof.

4. Medicament comprising at least one radioactive tracer in combination with at least one inert non-toxic pharmaceutical acceptable excipient, said radioactive tracer is of claim 3.

5. Medicament comprising at least one radioactive tracer in combination with at least one inert non-toxic pharmaceutical acceptable excipient, said radioactive tracer is of claim 2.

6. Radioactive tracer of claim 1, wherein X and Y independently from one another represent CH.sub.2, S or O, wherein X and Y are not simultaneously CH.sub.2, R.sub.1 and R.sub.2 are independently from another selected from the group consisting of (C.sub.1-C.sub.2)-alkyl, (C.sub.1-C.sub.2)-alkoxy and (C.sub.1-C.sub.2)-alkyl sulfonyl, wherein at least one of the residues represented by R.sub.1 and R.sub.2 is substituted with at least one substituent selected from the group consisting of .sup.76Br, .sup.75Br, .sup.19F and .sup.18F, and R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9 and R.sub.10 represent hydrogen, and the salts thereof, the solvates thereof and the solvates of the salts thereof.

7. Medicament comprising at least one radioactive tracer in combination with at least one inert non-toxic pharmaceutical acceptable excipient, said radioactive tracer is of claim 6.

8. Radioactive tracer of claim 1, selected from the group consisting of: 8-Ethyl-4-(2-fluoroethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]-oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium, 4-(2-Fluoroethyl)-8-(2-hydroxyethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium, [F-18]-8-Ethyl-4-(2-fluoroethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]-oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium, [F-18]-4-(2-Fluoroethyl)-8-(2-hydroxyethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium, [Br-75]-8-Ethyl-4-(2-bromoethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]-oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium, [Br-75]-4-(2-Bromoethyl)-8-(2-hydroxyethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium, [Br-76]-8-Ethyl-4-(2-bromoethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]-oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium, und [Br-76]-4-(2-Bromoethyl)-8-(2-hydroxyethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium, wherein the respective counterion is freely selectable.

9. Medicament comprising at least one radioactive tracer in combination with at least one inert non-toxic pharmaceutical acceptable excipient, said radioactive tracer is of claim 8.

10. Radioactive tracer of the formula (I) of claim 1 for a use in a method for diagnosing the Alzheimer's disease.

11. Medicament comprising at least one radioactive tracer in combination with at least one inert non-toxic pharmaceutical acceptable excipient, said radioactive tracer is of claim 1.

12. Medicament of claim 11 for a use in a method for the diagnosis of the Alzheimer's disease.

13. Method for the diagnosis of diseases in humans and animals, comprising the administration of a medicament of claim 11 to a human or animal in need thereof.

14. Method of claim 13, wherein said diseases are dementia diseases.

15. Method of claim 13, wherein said diseases are the Alzheimer's disease.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: OI scans of transgenic Alzheimer mice (right) and control animals (left), age 12 months each, after the administration of 0.1 mg/kg body weight of the compound of Example 3, measured 120 min after the injection,

(2) FIG. 2: OI scans of transgenic Alzheimer mice (right) and control animals (left) after the administration of 0.1 mg/kg body weight of the compound of Example 3, for animals at the age of 2 months (top row) and 12 months (low row),

(3) FIG. 3: a diagram where the signals measured in OI scans for the accumulation of the compound of Example 3 are plotted against the age of transgenic Alzheimer mice, and

(4) FIG. 4: a diagram where the signals measured in MRT scans for the accumulation of the compound of Example 1 and signals of corresponding measurements of the fluorescence are plotted against the measurement period.

DESCRIPTION OF PREFERRED EMBODIMENTS

(5) The percentages in the following tests and examples, unless specified otherwise, are % by weight; parts are parts by weight. Solvent ratios, dilution ratios and concentrations of liquid/liquid solutions each refer to the volume.

ABBREVIATIONS

(6) Aβ plaques amyloid beta peptide depositions Bz-Cl benzoe acid chloride DMAP 4-dimethylamino pyridine DMF N,N-dimethylformamide GC/MS gas chromatography coupled with mass spectrometry Kryptofix222 4,4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]-hexacosane MRT magnet resonance tomography MW molecular weight optical imaging PE petroleum ether or petroleum spirit PET positron emissions tomography PIB Pittsburgh compound B TBAF tetrabutylammonium fluoride trihydrate TBS-Cl chlor-tert-butyl dimethylsilane THF tetrahydrofuran Ts-Cl bzw. Tosyl-chlorid 4-toluolene sulfonic acid chloride

A. Analytical Apparatus and Methods

(7) GC/MS

(8) Agilent 7890 GC with a 5975C MSD with EI, column: HP5-MS, starting temperature: 50° C., linear temperature gradient to 300° C. within 20 min.

(9) Radio HPLC

(10) Agilent 1260 HPLC with MWD, RI and radio detector.

(11) LC/MS

(12) Agilent 1200 HPLC with MWD and MMI single quad MSD

(13) DC Scanner

(14) Perkin Elmer Cyclone Plus Phosphor Imager.

(15) IR Spectroscopy

(16) Perkin Elmer FT-IR Spectrum ONE with a ATR sampling unit. The samples were either measured in solid or liquid form directly with the ATR sampling unit without the use of pellets or cuvettes.

(17) UV/Vis Spectroscopy

(18) Perkin Elmer Lambda 25 UV/Vis spectrometer. The spectra were recorded in 3 ml quartz glass cuvettes with Uvasol methanol or TraceSelect water as solvent.

(19) Fluorescence Spectroscopy

(20) Perkin Elmer LS 45 fluorescence spectrometer. The spectra were recorded in 3 ml quartz glass cuvettes with Uvasol methanol or TraceSelect water as solvent.

B. Starting Compounds and Intermediates

Example 1A

2-(Ethyl(2-hydroxyethypannino)-1,4-benzochinone

(21) ##STR00009##

(22) To a solution of 1,4-benzochinone (0.3 mol) in 72 ml acetone at room temperature a solution of 2-(ethylamino)ethanol (0.15 mol) in 18 ml methanol was added in drops in such a way that the temperature of 30° C. was not exceeded. After the complete addition of the methanolic solution the dark brown suspension is stirred over night at room temperature. In the following the suspension is aspirated via a Büchner funnel and the obtained remainder is washed with little ice cold methanol. The yellowish to brown crystals were then dried in an exsiccator over night (yield: 16%).

(23) MW: 181.19 g/mol

(24) GC/MS: m/z=181 (30.8%), 152 (8.5%), 151 (12.3%), 150 (100.0%), 122 (38.5%), 108 (7.3%), 94 (13.3%), 82 (9.2%), 81 (14.8%), 79 (8.1%), 68 (12.5%), 55 (7.7%), 54 (8.2%), 53 (19.9%), 52 (7.4%).

Example 2A

2-(bis(2-Hydroxyethyl)amino)-1,4-benzochinone

(25) ##STR00010##

(26) The synthesis of the title compound is effected analogously to the synthesis of the compound of Example 1A, wherein diethanol amine is used instead of 2-(ethylannino)ethanol. The title compound is obtained in a yield of 77%.

(27) MW: 211.21 g/mol;

(28) GC/MS: m/z=211 (26.8%), 207 (19.6%), 195 (19.6%), 193 (15.0%), 182 (23.1%), 181 (13.7%), 180 (100.0%), 164 (37.7%), 162 (10.2%), 151 (13.4%), 150 (54.0%), 149 (12.7%), 136 (69.4%), 135 (10.1%), 122 (23.3%), 109 (16.(%), 108 (22.1%), 94 (10.(%), 82 (10.3%), 81 (16.7%), 80 (14.0%), 79 (11.2%), 68 (11.1%), 55 (17.6%), 54 (14.3%), 53 (24.5%), 52 (12.8%).

Example 3A

4-Methyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol

(29) ##STR00011##

(30) To a solution of the compound of Example 1A (0.1 mol) in 250 ml of 10% acetic acid zinc dust (0.2 mol) is added and the solution is heated for 30 min under reflux until the DC analysis shows a complete reaction conversion. The purple suspension is cooled down to room temperature, filtered through a Büchner funnel and the solid matter is washed with water. The filtrate is neutralized with concentrated ammoniac and for three times extracted with 200 ml ethyl acetate. The pooled organic phases are washed with saturated NaCl solution one time, dried via magnesium sulfate and concentrated in a rotary evaporator, resulting in a dark brown oil (yield: 53%).

(31) MW: 165.19 g/mol

(32) GC/MS: m/z=166 (10.1%), 165 (100.0%), 164 (13.9%), 150 (53.7%), 136 (22.4%), 123 (5.7%), 109 (10.8%), 108 (5.3%), 82 (15.5%), 81 (12.8%), 80 (5.4%), 55 (7.4%), 53 (6.9%).

Example 4A

4-Ethyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol

(33) ##STR00012##

(34) The synthesis of the title compound is effected analogously to the synthesis of the compound of Example 3A, starting from the compound of Example 2A. The title compound is obtained in a yield of 83%.

(35) MW: 179.22 g/mol

(36) GC/MS: m/z=180 (7.4%), 179 (63.1%), 165 (10.8%), 164 (100.0%), 150 (8.1%), 136 (22.5%), 123 (5.4%), 109 (7.7%), 108 (6.8%), 55 (5.1%).

Example 5A

4-(2-(tert-Butyldimethylsilyloxy)ethyl)-3,4-dihydro-2H-benzo[b]-[1,4]-oxazin-6-ol

(37) ##STR00013##

(38) To a solution of the compound of Example 4A (27.2 g, 0.139 mol, 1 equ.) in 300 ml DMF at room temperature at first DMAP (˜30 mg, cat. amount) and Et.sub.3N (29 ml, 0.210 mol, 1.5 equ.) are added. To this solution TBS-Cl (22.03 g, 0.146 mol, 1.05 equ.) is slowly added in portions in solid form, whereby an exothermic reaction can be observed. The obtained reaction solution is stirred at room temperature for 48 hours. For the reprocessing the reaction solution is supplemented with 1.5 l dest. water and the obtained cloudy solution is extracted for four times with 250 ml EtOAc. The pooled organic phases are washed for one time with 300 ml sat. NaCl solution, dried via MgSO.sub.4 and concentrated in a rotary evaporator. The obtained remainder is purified by means of column chromatography via silica gel with PE/EtOAc/Et.sub.3N=750:250:10 as the eluent, resulting in a dark brown oil (yield: 94%).

(39) MW: 309.48 g/mol

(40) GC/MS: m/z=310 (6.9%), 309 (29.8%), 252 (7.4%), 208 (7.9%), 165 (12.7%), 164 (100.0%), 136 (5.2%), 75 (4.0%), 73 (4.9%).

Example 6A

4-(2-(tert-Butyldimethylsilyloxy)ethyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl benzoate

(41) ##STR00014##

(42) To a solution of the compound of Example 5A (10.15 g, 32.8 mmol, 1 equ.) and Et.sub.3N (4.8 ml, 34.5 mmol, 1.05 equ.) in 200 ml dichloromethan at 0° C. a 10% solution of benzoyl chloride (4.0 ml, 34.5 mmol, 1.05 equ.) in dichloromethane is slowly added via a dropping funnel. After completing the addition, the reaction solution is maintained in the ice bath and stirred over night with slowly heating up to room temperature. For the reprocessing the brown reaction solution is supplemented with 400 ml dest. water and intensively stirred for 5 min. After the phase separation, the aqueous phase is extracted for three times with 200 ml dichloromethane. The pooled organic phases are then dried via MgSO.sub.4 and concentrated in a rotatory evaporator. The remainder is purified by means of a column chromatography via silica gel with PE/EtOAc/Et.sub.3N=500:100:5 as the eluent, resulting in a brown oil (yield: ˜quant.).

(43) MW: 413.58 g/mol

(44) GC/MS: m/z=324 (5.3%), 323 (22.0%), 266 (4.2%), 222 (3.3%), 179 (12.0%), 178 (100.0%), 150 (4.6%), 135 (2.4%), 75 (2.6%), 73 (3.7%), 59 (2.1%).

Example 7A

4-(2-Hydroxyethyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl benzoate

(45) ##STR00015##

(46) To a solution of the compound of Example 6A (26.2 mmol, 1 equ.) in 100 ml THF at 0° C. a solution of TBAF (27.5 ml, 27.5 mmol, 1.05 equ., 1M solution in THF) is slowly added and the reaction solution is stirred over night with slowly heating up to room temperature. For the reprocessing the reaction solution is supplemented with 150 ml dest. water and intensively stirred for 5 min. After the phase separation the aqueous solution is for three times extracted with 100 ml of Et.sub.2O each. The pooled organic phases are washed for one time with 100 ml of the saturated NaCl solution, dried via MgSO.sub.4 and concentrated in a rotary evaporator. The remainder is purified by means of column chromatography via silica gel with PE/EtOAc/Et.sub.3N=500:500:5 as the eluent, resulting in a light yellow oil (yield: 72%).

(47) MW: 299.32 g/mol;

(48) GC/MS: m/z=300 (5.0%), 299 (26.8%), 270 (2.2%), 269 (18.0%), 268 (100.0%), 164 (2.9%), 108 (5.6%), 106 (5.1%), 105 (52.7%), 78 (2.2%), 77 (26.4%), 55 (2.3%), 51 (4.8%).

Example 8A

4-(2-Fluoroethyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl benzoate

(49) ##STR00016##

(50) To a solution of the compound of Example 7A (4.49 g, 15 mmol, 1 equ.) in 100 ml THF at room temperature a solution of deoxofluor (13.0 ml, 30 mmol, 2.0 equ., 50% solution in THF) is added and the reaction mixture is stirred at this temperature over night. For the reprocessing the reaction mixture is supplemented with ˜50 g of silica gel and concentrated in a rotary evaporator to dryness. The remainder is purified by means of column chromatography via silica gel with PE/EtOAc/Et.sub.3N=300:150:5 as the eluent, resulting in a yellow oil (yield: 79%)

(51) MW: 301.31 g/mol

(52) GC/MS: m/z=302 (8.5%), 301 (44.6%), 269 (3.4%), 268 (18.5%), 168 (3.4%), 106 (8.4%), 105 (100.0%), 77 (28.9%), 51 (4.8%).

Example 9A

4-(2-Bromoethyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl-benzoate

(53) ##STR00017##

(54) To a solution of the compound of Example 7A (1 g, 3.34 mmol, 1 equ.) in 30 ml CHCl.sub.3 at room temperature CBr.sub.4 (2.23 g, 6.68 mmol, 2.0 equ.) followed by PPh.sub.3 (1.75 g, 6.68 mmol, 2.0 equ.) are added and the reaction mixture is stirred at this temperature for 60 min. After a complete conversion of the starting material has been determined by means of DC analysis, the cloudy solution is filtered and supplemented with ˜20 g of silica gel. The suspension is concentrated in a rotary evaporator to dryness and the obtained remainder is purified by means of column chromatography via silica gel with PE/EtOAc/Et.sub.3N=100:300:5 as the eluent, resulting in a yellow oil (yield ˜quant.).

(55) MW: 362.22 g/mol

(56) GC/MS: m/z=364 (4.3%), 363 (23.4%), 362 (4.7%), 361 (23.8%), 282 (2.6%), 269 (7.1%), 268 (39.9%), 109 (3.1%), 108 (3.5%), 107 (4.1%), 106 (8.4%), 105 (100.0%), 78 (2.3%), 77 (28.5%), 51 (4.7%).

Example 10A

4-(2-(Tosyloxy)ethyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl-benzoate

(57) ##STR00018##

(58) To a solution of the compound of Example 7A (1 g, 3.34 mmol, 1 equ.) and Et.sub.3N (0.7 mL, 5.0 mmol, 1.5 equ.) in 30 ml dichloromethane at 0° C. a solution of tosyl chloride (0.7 g, 3.67 mmol, 1.1 equ.) in 10 ml dichloromethane is slowly added in drops. The obtained reaction solution is stirred over night with slowly heating up. For the reprocessing the reaction solution is supplemented with 100 ml water and intensively stirred for 5 min. After the phase separation the aqueous phase is extracted for three times with 75 ml of dichloromethane. The pooled organic phases are washed for one time with 100 ml of a saturated NaCl solution, dried via MgSO.sub.4 and concentrated in a rotary evaporator, resulting in a brown oil. The remainder is purified by means of column chromatography via silica gel with PE/EtOAc/Et.sub.3N=300:100:5 as the eluent, resulting in a light brown oil, which solidifies when storing in the fridge (yield: 74%).

(59) MW: 453.51 g/mol

(60) GC/MS: m/z=342 (9.6%), 341 (35.7%), 281 (14.7), 269 (16.5%), 268 (100.0%), 208 (6.0%), 207 (25.6%), 148 (4.4%), 135 (4.6%), 108 (6.0%), 106 (8.8%), 105 (84.7%), 87 (8.4%), 78 (4.6%), 77 (27.1%), 73 (8.2%), 51 (4.8%).

Example 11A

[F-18]-4-(2-Fluoroethyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl-benzoate

(61) ##STR00019##
1. Step: Production of the Radioactive Fluoric Reagent

(62) In a 5 ml reaction vessel (reaction vial) 2 ml of aqueous H.sup.18F is deposited and at room temperature supplemented with 100 μl of a 3.5% of aqueous potassium carbonate solution, 16 mg of Kryptofix222 (Merck Darmstadt) and 1 ml acetonitrile (DNA grade). The solution is heated to 140° C. with intensive stirring in an argon gas stream. In intervals of 4 min 1 ml of acetonitrile each are added. 20 min after the reaction start it is verified whether there is still liquid present in the reaction vessel. If liquid is still present, the reaction mixture is stirred for additional 4 min. In the following the reaction vessel is cooled down to −30° C. and the remainder is dissolved into 1 ml acetonitrile, resulting in a yellow solution. This solution is then directly used for the radio labeling in the next step.

(63) 2. Step: Radio Labeling

(64) To a solution of the compound of Example 10A (4 mg) in 1 ml of abs. acetonitrile the solution of [K].sup.18F prepared in step 1 is added and the obtained reaction mixture is stirred at 85° C. for 30 min. After cooling down to −30° C. the reaction mixture is put onto a preparative HPLC (column: Phenomenex Luna C18(2), 250×10 mm, eluent: 60% acetonitrile/40% water, flow rate: 7 ml/min, detector: UV and radio activity) and the product is separated from the starting material. The product fraction is diluted with 70 ml of dest. water and put onto a conditioned Strata-X-SPE cartridge (Phenomenex, 10 mg bed material), whereby the radiolabeled product is retained on the bed material. In the following the Strata-X cartridge is washed with 5 ml water and the excessive water is removed with 5 ml of air. Finally, the product is eluated with 1 ml of 96% ethanol from the cartridge (yield: 22%).

(65) Die identification of the title compound is realized via radio-DC with PE/EtO.sub.2 as the eluent.

Example 12A

4-(2-Fluoroethyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol

(66) ##STR00020##

(67) To a solution of the compound of Example 8A (2 mmol, 1 equ.) in 30 ml of abs. methanol solid caustic soda (MW: 40.0 g/mol, 84 mg, 2.1 mmol, 1.05 eq.) is added and the reaction mixture is stirred at room temperature over night. For the reprocessing the reaction solution is supplemented with ˜25 g of silica gel and concentrated in a rotary evaporator to dryness. The remainder is separated by means of column chromatography via silica gel (eluent: PE/EtOAc/Et.sub.3N=400:600:5), resulting in an oil (yield: 99%).

(68) MW: 197.21 g/mol;

(69) GC/MS: m/z=198 (10.4%), 197 (79.6%), 168 (4.9%), 165 (16.2%), 164 (100.0%), 136 (29.2%), 123 (7.4%), 109 (12.0%), 108 (10.4%), 94 (4.3%), 82 (6.7%), 81 (5.7%), 65 (4.4%), 55 (5.2%), 53 (5.6%);

Example 13A

4-(2-Bromoethyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol

(70) ##STR00021##

(71) Die synthesis of the title compound is realized analogously to the synthesis of the compound of Example 12A, starting from the compound of Example 9A, whereby for the purification PE/EtOAc/Et.sub.3N=700:300:25 is used as the eluent. The title compound is obtained in a yield of >90%.

(72) The title compound is instable and decomposes within 12 hours to 50% at −25° C. For this reason the title compound is further converted directly after the isolation.

(73) MW: 258.11 g/mol;

(74) GC/MS: m/z=259 (20.7%), 257 (18.7%), 207 (4.4%), 178 (5.5%), 165 (11.7%), 164 (100.0%), 148 (3.9%), 136 (12.8%), 123 (4.4%), 109 (6.9%), 108 (4.6%), 94 (3.7%), 82 (4.3%), 55 (3.5%).

Example 14A

4-Ethyl-7-((4-nitrophenyl)diazenyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol

(75) ##STR00022##

(76) To a solution of the compound of Example 3A (3 mmol, 1 equ.) in 10 ml methanol at room temperature a solution of 4-nitro-phenyl-diazonium-tetrafluoroborate (710 mg, 3 mmol, 1 equ.) in 2 ml of 10% aqueous sulfuric acid is added. The dark red reaction solution is stirred for 30 min at room temperature and neutralized by half concentrated ammonia solution. The obtained red precipitate is filtered and washed on the filter with cold dest. water. In the following the red solid matter is dried in an oil pump vacuum over night and recrystallized from n-butanol (yield: 82%).

(77) MW: 328.32 g/mol;

(78) LC/MS: m/z=330 (19.3%), 329 (100.0%);

Example 15A

4-(2-Hydroxyethyl)-7-((4-nitrophenyl)diazenyl)-3,4-dihydro-2H-benzo[b][1,4]-oxazin-6-ol

(79) ##STR00023##

(80) The synthesis of the title compound is realized analogously to the synthesis of the compound of Example 14A, starting from the compound of Example 4A. The title compound is obtained in a yield of 94%.

(81) MW: 344.32 g/mol;

(82) LC/MS: m/z=346 (19.0%), 345 (100.0%);

C. Exemplary Compounds

Example 1

8-Ethyl-4-(2-fluoroethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium chloride

(83) ##STR00024##

(84) To a solution of the compound of Example 14A (2 mmol, 1 equ.) and of the compound of Example 12A (3 mmol, 1.5 equ.) in 12 ml of 90% ethanol 1 ml of 32% hydrochloric acid is added and the reaction solution is heated for 60-240 min under reflux (˜80° C.) until the DC or LC/MS analysis shows a complete reaction conversion. For the reprocessing the reaction solution is neutralized with concentrated ammonia solution and concentrated in a rotary evaporator to dryness. The obtained remainder is dissolved in methanol, supplemented with ˜10 g silica gel and again concentrated in the rotary evaporator to dryness. The green blue remainder is purified by means of column chromatography via silica gel with CH.sub.2Cl.sub.2/MeOH=20:1 as the eluent, resulting in a greenish to blue solid matter (yield: 62%).

(85) MW: 405.85 g/mol

(86) LC/MS: m/z=371 (22.9%), 370 (100.0%).

Example 2

4-(2-Bromoethyl)-8-ethyl-3,8,9,10-tetrahydro-2H-bis([1,4]oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium bromide

(87) ##STR00025##

(88) The synthesis of the title compound is realized analogously to the synthesis of the compound of Example 1, starting from the compounds of Example 14A and Example 13A. After the purification of the raw product by means of column chromatography with silica gel and CH.sub.2Cl.sub.2/MeOH=1000:50 as the eluent the title compound is obtained in a yield of 24%.

(89) This compound does not fall under the scope of protection of claim 1 and merely serves as a non-radioactive model compound for .sup.76Br and .sup.75Br substituted compounds.

(90) MW: 511.12 g/mol

(91) LC/MS: m/z=436 (13.8%), 435 (46.4%), 434 (19.8%), 433 (57.0%), 247 (15.0%), 231 (10.1%), 230 (13.3%), 213 (13.7%), 207 (10.2%), 166 (100.0%), 138 (21.5%), 137 (65.1%), 125 (16.0%), 124 (49.5%);

Example 3

[F-18]-8-Ethyl-4-(2-Fluoroethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]-oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium chloride

(92) ##STR00026##

(93) To an ethanolic solution of the compound of Example 11A at room temperature 2 mg of solid caustic soda are added and the reaction mixture is stirred at 50° C. for 5 min, whereby a complete conversion is observed by means of radio DC. To this reaction solution a solution consisting of the compound of Example 14A (4 mg) and 50 μl of concentrated hydrochloric acid are added and the reaction mixture is stirred at 75° C. for 20 min. The reaction mixture is purified by HPLC and the title compound is obtained in a yield of 8%.

(94) The identification of the title compound is realized via radio DC with CH.sub.2Cl.sub.2/MeOH 10:1 as the eluent and radio HPLC with the compound of Example 1 as the reference substance.

Example 4

4-(2-Fluoroethyl)-8-(2-hydroxyethyl)-3,8,9,10-tetrahydro-2H-bis([1,4]oxazino)[2,3-b:3′,2′-i]phenoxazin-4-ium chloride

(95) ##STR00027##

(96) The synthesis of the title compound is realized analogously to the synthesis of the compound of Example 1, starting from the compounds of Example 15A and Example 12A. After the purification of the raw product by column chromatography with silica gel and a gradient of CH.sub.2Cl.sub.2/MeOH=20:1 to CH.sub.2Cl.sub.2/MeOH=1:1 the title compound is obtained in a yield of 24%.

(97) MW: 421.85 g/mol

(98) LC/MS: m/z=388 (7.6%), 387 (29.0%), 386 (100.0%), 385 (6.0%).

D. Evaluation of the Physiological Activity

(99) Detection of Aβ Plaques by Means of Optical Imaging (OI) in the Mouse Model

(100) To demonstrate the selective labeling of Aβ plaques by radioactively labeled compounds of the invention and of the imaging of the labeling by OI, transgenic APPPS1 mice and non-transgenic control mice of different age (provided by Prof. Mathias Jucker, Department of Cellular Neurology, Hertie-Institute for Clinical Brain Research, University of Tubingen) were treated with 0.1 mg/kg body weight of the compound of Example 3 and then examined by means of OI. The compound was formulated in physiological saline solution (0.9% NaCl) in a concentration of 0.05 mg/ml and intravenously injected into the mice. In the following the mice were examined by means of OI (Aequoria Hamamatsu Optical Imaging System), the signal was detected at 650 nm.

(101) The experiments are intended to demonstrate the general capability of the compounds according to the invention to bind to Aβ plaques and to provide a signal correlating with the concentration of Aβ plaques. It is clear for the skilled person that this labeling can—depending on the kind of labeling—be realized by any method, such as OI, PET (e.g. with .sup.76Br, .sup.75Br or .sup.18F labeled compounds) or MRT (e.g. with .sup.19F labeled compounds).

(102) These experiments have shown that the compound of Example 3 specifically accumulates in transgenic mice wherein in the control mice no accumulation could be detected (see FIG. 1).

(103) It has further been shown that the enrichment of the compound of Example 3 increases with the age of the transgenic mice and hence with the increasing formulation of Aβ plaques. It can be seen that in transgenic mice of an age of 2 months where Aβ plaques rarely have been formed no enrichment can be detected, whereas at the age of 12 months a significant enrichment can be seen (see FIG. 2).

(104) The signal strength was quantified as a relative fluorescence signal, whereby 30 min after the injection was chosen as the reference point in time. The signal strength was calculated by percentage after the subtraction of the auto fluorescence (resulting in relative intensity values, I.sub.rel) and then the percentage difference between the transgenic and control mice—in the following referred to as specific binding (B.sub.sp)—was calculated and plotted against the age of the transgenic mice (see FIG. 3). It turned out that there is a significant correlation between the age and the development of the Alzheimer's disease and the signal strength, where it was especially noted that the compound according to the invention has no saturation or ceiling effects in a way that the signal strength is not increasing at a specific concentration of Aβ plaques. To the contrary, at the age of 21 months for the transgenic mice a particularly strong signal has been measured.

(105) Detection of Aβ Plaques by Means of MRT in the Mice Model

(106) For the demonstration of the selective labeling of Aβ plaques by the fluor labeled compounds of the invention and the imaging of the labeling by MRT, trangenic APP23 mice and non-transgenic control mice (provided by Dr. Matthias Staufenbiel, Novartis Institutes for BioMedical Research, Basel, Switzerland) at the age of 28 months were treated with 2 mg/kg body weight of the compound of Example 1 (the compound was formulated in physiological saline solution (0.9% NaCl) in a concentration of 1 mg/ml) and then examined by means of MRT (ClinScan, Bruker BioSpin MRI, Ettlingen, Germany) and analyzed by optical fluorescence measurements (Aequoria Hamamatsu Optical Imaging System) and evaluated as described before. For the MRT measurements a threedimensional gradient echosequence (gre3D) which both comprises T1 as well as T2* parts, and a quantitative T2 value determination sequence (T2map) were used. By doing so, again a specific enrichment in the transgenic mice could be detected over the measurement time period of 90 minutes. In the control mice neither for the MRT measurements nor the fluorescence measurements a specific enrichment of the compound of Example 1 could be observed.

(107) The values obtained from the MRT were compared with the values of the fluorescence measurement resulting in a significant correlation as can be seen in the diagram of FIG. 4. The observations made in vivo could also be confirmed ex vivo after a preparation of the brains.

(108) Summary

(109) With these experiments the suitability of the compounds according to the invention for the labeling in vivo of Aβ plaques and their non-invasive detection could be demonstrated by OI as well as by MRT. It has been shown that the compounds according to the invention bind to Aβ plaques with high selectivity and provide a signal correlating with the concentration of Aβ plaques over a wide concentration range. It results from the OI examinations by using the compound of Example 3 that this compound selectively binds to Aβ plaques, where it is clear to the skilled person that this compound, due to the presence of .sup.18F, is also suitable for the analysis by PET and will provide analogous results. The compounds according to the invention are therefore excellently suited for the non-invasive diagnosis of the Alzheimer's disease and the monitoring of the process of the disease.