[1,2,3]triazolo[4,5-D]pyrimidine derivatives

Abstract

The invention relates to a compound of formula (I) ##STR00001##
wherein R.sup.1 to R.sup.4 are defined as in the description and in the claims. The compound of formula (I) can be used as a medicament.

Claims

1. A compound of formula (I) ##STR00035## wherein R.sup.1 is a ring selected from phenyl, [1,2,5]oxadiazolyl, pyridinyl and pyrimidinyl, wherein said ring is substituted with one substituent selected from haloalkyldiazirenyl and alkynyldiazirenylalkylaminocarbonyl and optionally further substituted with halogen or cyano; R.sup.2 and R.sup.3 are independently selected from hydrogen, halogen and hydroxyl; and R.sup.4 is alkyl or phenylhaloalkyl; or a pharmaceutically acceptable salt or ester thereof.

2. The compound according to claim 1, wherein R.sup.1 is a ring selected from phenyl, [1,2,5]oxadiazolyl, pyridinyl and pyrimidinyl, wherein said ring is substituted with one substituent selected from trifluoromethyldiazirenyl and butynyldiazirenylethylaminocarbonyl and wherein said ring is optionally further substituted with chlorine or cyano.

3. The compound according to claim 1, wherein R.sup.1 is trifluoromethyldiazirenyl(chloro)phenyl, butynyldiazirenylethylaminocarbonyl[1,2,5]oxadiazolyl, trifluoromethyldiazirenylphenyl, trifluoromethyldiazirenylpyridinyl, trifluoromethyldiazirenylpyrimidinyl or trifluoromethyldiazirenyl(cyano)phenyl.

4. The compound according to claim 1, wherein R.sup.1 is butynyldiazirenylethylaminocarbonyl[1,2,5]oxadiazolyl.

5. The compound according to claim 1, wherein R.sup.2 and R.sup.3 are independently selected from hydrogen, fluoro and hydroxyl.

6. The compound according to claim 1, wherein R.sup.2 and R.sup.3 are both fluoro, or one of R.sup.2 and R.sup.3 is hydrogen and the other one is hydroxyl.

7. The compound according to claim 1, wherein R.sup.4 is tert-butyl or phenyldifluoromethyl.

8. The compound according to claim 1, wherein R.sup.4 is tert-butyl.

9. The compound according to claim 1 selected from the group consisting of: 5-tert-butyl-2-({2-chloro-4-[3-(trifluoromethyl)-3H-diaziren-3-yl]phenyl}methyl)-7-(3,3-difluoropyrrolidin-1-yl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; 4-{[5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-2-yl]methyl}-N-{2-[3-(but-3-yn-1-yl)-3H-diaziren-3-yl]ethyl}-1,2,5-oxadiazole-3-carboxamide; 4-({5-tert-butyl-7-[(3S)-3-hydroxypyrrolidin-1-yl]-2H-[1,2,3]triazolo[4,5-d]pyrimidin-2-yl}methyl)-N-{2-[3-(but-3-yn-1-yl)-3H-diaziren-3-yl]ethyl}-1,2,5-oxadiazole-3-carboxamide; 5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2-({2-[3-(trifluoromethyl)-3H-diaziren-3-yl]phenyl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; 5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2-({3-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-2-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; (3S)-1-[5-tert-butyl-2-({3-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-2-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol; 5-[difluoro(phenyl)methyl]-7-(3,3-difluoropyrrolidin-1-yl)-2-({3-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-2-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; (3S)-1-{5-[difluoro(phenyl)methyl]-2-({3-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-2-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl}pyrrolidin-3-ol; 5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2-({4-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-3-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; (3S)-1-[5-tert-butyl-2-({4-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-3-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol; 5-[difluoro(phenyl)methyl]-7-(3,3-difluoropyrrolidin-1-yl)-2-({4-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-3-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; (3S)-1-{5-[difluoro(phenyl)methyl]-2-({4-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-3-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl}pyrrolidin-3-ol; 5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2-({5-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyrimidin-4-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; (3S)-1-[5-tert-butyl-2-({5-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyrimidin-4-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol; 5-[difluoro(phenyl)methyl]-7-(3,3-difluoropyrrolidin-1-yl)-2-({5-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyrimidin-4-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; (3S)-1-{5-[difluoro(phenyl)methyl]-2-({5-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyrimidin-4-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl}pyrrolidin-3-ol; 5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2-({3-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-4-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; (3S)-1-[5-tert-butyl-2-({3-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-4-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol; 5-[difluoro(phenyl)methyl]-7-(3,3-difluoropyrrolidin-1-yl)-2-({3-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-4-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; (3S)-1-{5-[difluoro(phenyl)methyl]-2-({3-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-4-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl}pyrrolidin-3-ol; 5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2-({5-[3-(trifluoromethyl)-3H-diaziren-3-yl]pyridin-2-yl}methyl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine; 5-[difluoro(phenyl)methyl]-7-(3,3-difluoropyrrolidin-1-yl)-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidine; 5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidine; (3S)-1-[5-tert-butyl-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol; and (3S)-1-[5-[difluoro(phenyl)methyl]-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol; or a pharmaceutically acceptable salt thereof.

10. The compound according to claim 1 selected from the group consisting of: 4-{[5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-2-yl]methyl}-N-{2-[3-(but-3-yn-1-yl)-3H-diaziren-3-yl]ethyl}-1,2,5-oxadiazole-3-carboxamide; and (3S)-1-[5-tert-butyl-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol; or a pharmaceutically acceptable salt thereof.

11. A process for the manufacture of a compound according to claim 1 comprising the reaction of a compound of formula (A) ##STR00036## in the presence of R.sup.1CH.sub.2X and a base, or in the presence of R.sup.1CH.sub.2OH under Mitsunobu conditions, wherein R.sup.1 to R.sup.4 are as defined in claim 1 and wherein X is a leaving group.

12. A compound manufactured according to the process of claim 11.

13. A pharmaceutical composition comprising a compound of claim 1, or a pharmaceutically acceptable salt or ester thereof, and a therapeutically inert carrier.

14. A method for the treatment of pain, which method comprises administering an effective amount of a compound of claim 1, or a pharmaceutically acceptable salt or ester thereof, to a patient in need thereof.

15. The compound according to claim 4, wherein R.sup.2 and R.sup.3 are both fluoro, or one of R.sup.2 and R.sup.3 is hydrogen and the other one is hydroxyl.

16. The compound according to claim 15, wherein R.sup.4 is tert-butyl.

17. The method of claim 14, wherein the pain is a neuropathic pain.

Description

EXAMPLES

Abbreviations

(1) MS=mass spectrometry; CAN=ceric ammonium nitrate; CAN=chemical abstract service number; Ac=acetyl; DIEA=N,N-diisopropylethylamine; DBU=1,8-Diazabicyclo[5.4.0]undec-7-ene; DMF=dimethylformamide; HPLC=LC=high performance liquid chromatography; HRMS=high resolution mass spectrometry; MeCN=acetonitrile; NBS=N-Bromosuccinimide; NCS=N-Chloroosuccinimide; NMR data are reported in parts per million (6) relative to internal tetramethylsilane and are referenced to the deuterium lock signal from the sample solvent (d.sub.6-DMSO unless otherwise stated); coupling constants (J) are in Hertz; THF=tetrahydrofurane; TFA=trifluoroacetic acid; DCM=dichloromethane.

Example 1

5-tert-Butyl-2-({2-chloro-4-[3-(trifluoromethyl)-3H-diaziren-3-yl]phenyl}methyl)-7-(3,3-difluoropyrrolidin-1-yl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine

(2) ##STR00007##

a) 1-(3-Chloro-4-methylphenyl)-2,2,2-trifluoroethanone

(3) ##STR00008##

(4) 4-Bromo-2-chloro-1-methylbenzene (5.0 g, 24.3 mmol, 1.0 equiv) was dissolved in THF (50 mL) and cooled to 78 C. BuLi (1.6 M in hexanes, 17 mL, 27.2 mmol, 1.12 equiv) was added dropwise. After completion of the addition the reaction mixture was stirred for 30 min before 2,2,2-trifluoro-N-methoxy-N-methylacetamide (4.0 g, 25.5 mmol, 1.05 equiv) was added. The cooling bath was removed and it was stirred for 20 minutes. The reaction was quenched by the addition of sat. aq. NH.sub.4Cl and extracted with EtOAc. The combined organics were washed with aq. HCl (1 M) and brine, dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (20% Et.sub.2O in pentane) afforded 1-(3-chloro-4-methylphenyl)-2,2,2-trifluoroethanone (5.17 g, 23.2 mmol, 95% yield) as yellow oil. .sup.1H NMR (300 MHz, Chloroform-d) =8.04 (s, 1H), 7.89-7.83 (m, 1H), 7.45-7.39 (m, 1H), 2.49 (s, 3H).

b) 1-(3-Chloro-4-methylphenyl)-2,2,2-trifluoroethanone oxime

(5) ##STR00009##

(6) 1-(3-Chloro-4-methylphenyl)-2,2,2-trifluoroethanone (3.67 g, 16.5 mmol, 1.0 equiv) and hydroxylamine hydrochloride (1.20 g, 17.3 mmol, 1.05 equiv) were combined with EtOH (32 mL). Pyridine (6.7 mL, 82 mmol, 5.0 equiv) was added and the mixture was stirred at 70 C. overnight. After cooling to room temperature, water (200 mL) was added and the mix was extracted with Et.sub.2O. The combined organics were washed with HCl (aq. 0.5 M) and brine. The organic phase was dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (10% EtOAc in hexanes) afforded 1-(3-chloro-4-methylphenyl)-2,2,2-trifluoroethanone oxime (3.45 g, 14.5 mmol, 88% yield). .sup.1H NMR (400 MHz, Chloroform-d) =9.24 (s, 1H), 7.58 (s, 1H), 7.35 (app s, 2H), 2.44 (s, 3H).

c) 1-(3-Chloro-4-methylphenyl)-2,2,2-trifluoroethanone O-tosyl oxime

(7) 1-(3-chloro-4-methylphenyl)-2,2,2-trifluoroethanone oxime (2.9 g, 12.2 mmol, 1.0 equiv), NEt.sub.3 (1.87 mL, 13.4 mmol, 1.1 equiv) and DMAP (149 mg, 1.22 mmol, 0.1 equiv) were dissolved in CH.sub.2Cl.sub.2 (49 mL) and cooled to 0 C. Then a solution of TsCl (2.56 g, 13.4 mmol, 1.1 equiv) in CH.sub.2Cl.sub.2 (25 mL) was added. Upon complete addition the cooling bath was removed and it was stirred at room temperature until TLC indicated complete consumption of starting material. Water was added and the mix was extracted with EtOAc. The organics were washed with brine, dried over MgSO.sub.4, filtered and concentration. Flash chromatography on silica (10% Et.sub.2O in pentane) afforded 1-(3-chloro-4-methylphenyl)-2,2,2-trifluoroethanone O-tosyl oxime (3.9 g, 9.95 mmol, 82% yield) as colorless solid. HRMS (ESI+) 392.0329 (M+H.sup.+).

d) 3-(3-Chloro-4-methylphenyl)-3-(trifluoromethyl)-3H-diazirine

(8) ##STR00010##

(9) 1-(3-Chloro-4-methylphenyl)-2,2,2-trifluoroethanone O-tosyl oxime (850 mg, 2.17 mmol) was dissolved in Et.sub.2O (30 mL) and cooled to 78 C. Ammonia (ca. 15 mL) was condensed into the flask and the reaction mixture was stirred overnight (thereby warmed to room temperature). The reaction mix was filtered and the solids were washed with Et.sub.2O. The filtrate was concentrated and purified by flash chromatography on silica (10% Et.sub.2O in pentane) to give the intermediate diaziridine (464 mg, 1.96 mmol, 90% yield). The intermediate was dissolved in Et.sub.2O (10 mL) and Ag.sub.2O (858 mg, 3.7 mmol, 2.0 equiv) was added. After 15 min, the reaction mixture was filtered over celite and concentrated to afford 3-(3-chloro-4-methylphenyl)-3-(trifluoromethyl)-3H-diazirine (410 mg, 1.75 mmol, 94% yield) as yellow oil. .sup.1H NMR (400 MHz, Chloroform-d) =7.62-7.57 (m, 1H), 7.38-7.34 (m, 1H), 7.28-7.23 (m, 1H), 2.62 (s, 3H).

e) 3-(4-(Bromomethyl)-3-chlorophenyl)-3-(trifluoromethyl)-3H-diazirine

(10) ##STR00011##

(11) 3-(3-Chloro-4-methylphenyl)-3-(trifluoromethyl)-3H-diazirine (365 mg, 1.56 mmol, 1.00 equiv), benzoyl peroxide (23 mg, 0.10 mmol, 0.06 equiv) and NBS (731 mg, 4.11 mmol, 2.64 equiv) were combined with CCl.sub.4 and heated to reflux until TLC indicated full consumption of the starting material. Celite was added and the solvent was removed. Flash chromatography on silica afforded 3-(4-(bromomethyl)-3-chlorophenyl)-3-(trifluoromethyl)-3H-diazirine (320 mg, 1.02 mmol, 66% yield) as yellow oil. .sup.1H NMR (300 MHz, Chloroform-d) =7.48 (d, J=8.2, 1H), 7.23-7.18 (m, 1H), 7.09 (d, J=8.1, 1H), 4.56 (s, 2H).

d) 5-tert-Butyl-3-({2-chloro-4-[3-(trifluoromethyl)-3H-diaziren-3-yl]phenyl}methyl)-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine

(12) 5-tert-Butyl-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (CAS 1438465-59-8, 54 mg, 0.19 mmol, 1.0 equiv) and 3-(4-(bromomethyl)-3-chlorophenyl)-3-(trifluoromethyl)-3H-diazirine (66 mg, 0.21 mmol, 1.1 equiv) were dissolved in DMF (1 mL). DBU (38 L, 0.25 mmol, 1.3 equiv) was added and the reaction mix was for 30 min. The mix was poured on water and extracted with EtOAc (3). The organics were washed with brine. The aqueous phase was extracted CH.sub.2Cl.sub.2. The combined organics were over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (hex/DCM 1:1+0.5% MeOH) afforded 5-tert-butyl-3-({2-chloro-4-[3-(trifluoromethyl)-3H-diaziren-3-yl]phenyl}methyl)-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (27 mg, 0.052 mmol, 27% yield) as slightly yellow wax. .sup.1H NMR (400 MHz, Chloroform-d) =7.25-7.20 (m, 2H), 7.08-7.04 (m, 1H), 5.92 (s, 2H), 4.48-4.28 (m, 2H), 4.12 (dd, J=28.1, 15.2, 2H), 2.65-2.44 (m, 2H), 1.39 (s, 9H).

Example 2

4-{[5-tert-Butyl-7-(3,3-difluoropyrrolidin-1-yl)-2H-[1,2,3]triazolo[4,5-d]pyrimidin-2-yl]methyl}-N-{2-[3-(but-3-yn-1-yl)-3H-diaziren-3-yl]ethyl}-1,2,5-oxadiazole-3-carboxamide

(13) ##STR00012##

a) N-(2-(3-(But-3-yn-1-yl)-3H-diazirin-3-yl)ethyl)-4-(hydroxymethyl)-1,2,5-oxadiazole-3-carboxamide

(14) ##STR00013##

(15) 3-(But-3-ynyl)-3-(2-aminoethyl)-3H-diazirine (CAS 1450752-97-2, 96 mg, 0.70 mmol, 1.0 equiv) was dissolved in toluene (2.3 mL) and cooled to 0 C. AlMe.sub.3 (2 M in toluene, 370 L, 0.74 mmol, 1.06 equiv) was added slowly. After 30 min at 0 C., a solution 6H-furo[3,4-c][1,2,5]oxadiazol-4-one (CAS 73314-58-6, 106 mg, 0.84 mmol, 1.2 equiv) in toluene (1 mL) was added slowly. The cooling bath was removed and the mixture was stirred at room temperature for 1 h. A precipitate formed, THF (1 mL) was added and stirring was continued for 1 h. The reaction was quenched by the addition of a sat. aq. solution of Rochelle's salt (2 mL) and water (2 mL). EtOAc (5 mL) was added and the reaction mix was vigorously stirred for 1 h. Extraction with EtOAc (35 mL), washing with brine, drying over MgSO.sub.4, filtration and concentration followed by flash chromatography on silica (25% EtOAc in hexanes) afforded N-(2-(3-(but-3-yn-1-yl)-3H-diazirin-3-yl)ethyl)-4-(hydroxymethyl)-1,2,5-oxadiazole-3-carboxamide (171 mg, 0.65 mmol, 93% yield) as yellowish oil. HRMS (ESI+) 264.1096 (M+H.sup.+).

b) (4-((2-(3-(But-3-yn-1-yl)-3H-diazirin-3-yl)ethyl)carbamoyl)-1,2,5-oxadiazol-3-yl)methyl methanesulfonate

(16) ##STR00014##

(17) N-(2-(3-(but-3-yn-1-yl)-3H-diazirin-3-yl)ethyl)-4-(hydroxymethyl)-1,2,5-oxadiazole-3-carboxamide (87 mg, 0.33 mmol, 1.0 equiv) and NEt.sub.3 (69 L, 0.50 mmol, 1.5 equiv) were dissolved in CH.sub.2Cl.sub.2 (1.1 mL) and cooled to 0 C. MsCl (31 L, 0.40 mmol, 1.2 equiv) was added. After 30 minutes, MeOH (0.1 mL) and celite were added and the solvent was removed. Flash chromatography on silica (30% EtOAc in hexanes to 40% EtOAc in hexanes) afforded (4-((2-(3-(but-3-yn-1-yl)-3H-diazirin-3-yl)ethyl)carbamoyl)-1,2,5-oxadiazol-3-yl)methyl methanesulfonate (90 mg, 0.26 mmol, 80% yield) as colorless oil.

c) 4-{[5-tert-Butyl-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-3-yl]methyl}-N-{2-[3-(but-3-yn-1-yl)-3H-diaziren-3-yl]ethyl}-1,2,5-oxadiazole-3-carboxamide

(18) (4-((2-(3-(But-3-yn-1-yl)-3H-diazirin-3-yl)ethyl)carbamoyl)-1,2,5-oxadiazol-3-yl)methyl methanesulfonate (45 mg, 0.13 mmol, 1.0 equiv) and 5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (CAS 1438465-59-8, 37 mg, 0.13 mmol, 1.0 equiv) were dissolved in DMF (0.44 mL) and NEt.sub.3 (37 L, 0.26 mmol, 2.0 equiv) was added. After 30 min, EtOAc (30 mL) was added. It was washed with 5% aq. LiCl and brine, dried over MgSO.sub.4 and concentrated. Flash chromatography on silica afforded 4-{[5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-3-yl]methyl}-N-{2-[3-(but-3-yn-1-yl)-3H-diaziren-3-yl]ethyl}-1,2,5-oxadiazole-3-carboxamide (12 mg, 0.023 mmol, 17% yield) as yellowish oil. HRMS (ESI+) 528.2387 (M+H.sup.+).

Example 3

4-({5-tert-Butyl-7-[(3S)-3-hydroxypyrrolidin-1-yl]-2H-[1,2,3]triazolo[4,5-d]pyrimidin-2-yl}methyl)-N-{2-[3-(but-3-yn-1-yl)-3H-diaziren-3-yl]ethyl}-1,2,5-oxadiazole-3-carboxamide

(19) ##STR00015##

(20) In analogy to the procedure described for the synthesis of 4-{[5-tert-butyl-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-3-yl]methyl}-N-{2-[3-(but-3-yn-1-yl)-3H-diaziren-3-yl]ethyl}-1,2,5-oxadiazole-3-carboxamide (example 2, step c) the title compound was prepared from (4-((2-(3-(but-3-yn-1-yl)-3H-diazirin-3-yl)ethyl)carbamoyl)-1,2,5-oxadiazol-3-yl)methyl methanesulfonate (40 mg, 0.12 mmol, 1.0 equiv) and (3S)-1-(5-tert-butyl-3H-triazolo[4,5-d]pyrimidin-7-yl)pyrrolidin-3-ol (CAS 1433946-74-7, 31 mg, 0.12 mmol, 1.0 equiv) and isolated as a colorless oil. HRMS (ESI+) 508.2524 (M+H.sup.+).

Example 4

5-[Difluoro(phenyl)methyl]-7-(3,3-difluoropyrrolidin-1-yl)-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidine

(21) ##STR00016##

a) 2,6-Diiodobenzyl Alcohol

(22) ##STR00017##

(23) 2,6-Diiodibenzoic acid (CAS 194084-84-9, 2.13 g, 5.35 mmol, 1.00 equiv) was suspended in CH.sub.2Cl.sub.2 (10.7 mL). DMF (3 drops) and oxalyl chloride (0.52 mL, 5.9 mmol, 1.1 equiv) were added. When bubbling ceased, the reaction mixture was heated to reflux for 30 minutes (TLC indicated full consumption of starting material). It was diluted with CH.sub.2Cl.sub.2, washed with sat. aq. sodium bicarbonate and brine, dried over MgSO.sub.4, filtered and concentrated. The crude acid chloride was dissolved in a 1:1 mixture of MeCN and THF (30 mL). NaBH.sub.4 (405 mg, 10.7 mmol, 2.00 equiv) was added in portions at rt (exotherm). After 30 min TLC indicated full conversion of acid chloride. MeOH (5 mL) was added slowly and the resulting mixture was diluted with water. Extraction with EtOAc (3100 mL), washing with brine (100 mL), drying over MgSO.sub.4, filtration and concentration followed by flash chromatography on silica (15% EtOAc in hexanes to 20% to 50%) afforded the title compound as colorless solid (1.55 g, 4.31 mmol, 80%). HRMS (MALDI) 382.8399 (M+Na.sup.+).

b) 1,3-Diiodo-2-(((4-methoxybenzyl)oxy)methyl)benzene

(24) ##STR00018##

(25) 2,6-Diiodobenzyl alcohol (1.61 g, 4.47 mmol, 1.00 equiv) was dissolved in DMF and cooled to 0 C. NaH (60% in mineral oil, 215 mg, 5.37 mmol, 1.20 equiv) was added and the mixture was stirred for 20 min. 4-Methoxybenzyl chloride (0.67 mL, 4.9 mmol, 1.1 equiv) was added and the cooling bath was removed. After 30 min, the reaction was quenched by the addition of sat. aq. NH.sub.4Cl (5 mL). The mix was extracted with EtOAc (350 mL). The combined organics were washed with 5% aq. LiCl (50 mL) and brine (50 mL), dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (5% EtOAc in hexanes) afforded the title compound as colorless solid (1.9 g, 4.0 mmol, 88%). HRMS (MALDI) 479.9078 (M.sup.+).

c) 2,2,2-Trifluoro-1-(3-iodo-2-(((4-methoxybenzyl)oxy)methyl)phenyl)ethanone

(26) ##STR00019##

(27) 1,3-Diiodo-2-(((4-methoxybenzyl)oxy)methyl)benzene (1.9 g, 4.0 mmol, 1.0 equiv) was dissolved in THF (8 mL) and cooled to 30 C. A solution of iPrMgCl.LiCl (0.87 M, 5.0 mL, 4.35 mmol, 1.10 equiv) was added and the resulting solution was stirred for 2.5 h, while the temperature was allowed to rise to 20 C. N-methoxy-N-methyltrifluoroacetamide (0.68 g, 4.4 mmol, 1.1 equiv) was added, the cooling bath was removed and the reaction was stirred overnight. Sat. aq. NH.sub.4Cl was added and it was extracted with EtOAc. The organics were washed with brine, dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica afforded the title compound as colorless oil (1.04 g, 2.31 mmol, 58%). .sup.1H NMR (400 MHz, CDCl.sub.3) 7.95 (dd, J=7.9, 1.2 Hz, 1H), 7.35 (dd, J=7.6, 1.0 Hz, 1H), 7.25 (d, J=8.1 Hz, 2H), 7.09 (t, J=7.8 Hz, 1H), 6.90 (d, J=8.7 Hz, 2H), 4.57 (s, 2H), 4.48 (s, 2H), 3.82 (s, 3H).

c) 2,2,2-Trifluoro-1-(3-iodo-2-(((4-methoxybenzyl)oxy)methyl)phenyl)ethanone oxime

(28) ##STR00020##

(29) 2,2,2-Trifluoro-1-(3-iodo-2-(((4-methoxybenzyl)oxy)methyl)phenyl)ethanone (1.04 g, 2.31 mmol, 1.00 equiv) was combined with EtOH (4.6 mL), hydroxylamine hydrochloride (193 mg, 2.77 mmol, 1.20 equiv) and pyridine (0.28 mL, 3.5 mmol, 1.5 equiv). The mixture was heated at 80 C. until TLC indicated full consumption of starting material. Concentration and flash chromatography on silica afforded the title compound (680 mg, 1.46 mmol, 63%).

d) 2,2,2-Trifluoro-1-(3-iodo-2-(((4-methoxybenzyl)oxy)methyl)phenyl)ethanone O-tosyl oxime

(30) ##STR00021##

(31) 2,2,2-Trifluoro-1-(3-iodo-2-(((4-methoxybenzyl)oxy)methyl)phenyl)ethanone oxime (680 mg, 1.46 mmol, 1.00 equiv) was dissolved in CH.sub.2Cl.sub.2 (3 mL). TsCl (307 mg, 1.61 mmol, 1.10 equiv) and DMAP (18 mg, 0.15 mmol, 0.10 equiv) were added and the mixture was stirred at rt. When TLC indicated full consumption of starting material, water was added. Extraction with CH.sub.2Cl.sub.2, washing with brine, drying over MgSO.sub.4, filtration and concentration followed by flash chromatography afforded the title compound as a 2:1 mixture of diastereomers (529 mg, 0.85 mmol, 58%).

e) 3-(3-odo-2-(((4-methoxybenzyl)oxy)methyl)phenyl)-3-(trifluoromethyl)-3H-diazirine

(32) ##STR00022##

(33) 2,2,2-Trifluoro-1-(3-iodo-2-(((4-methoxybenzyl)oxy)methyl)phenyl)ethanone O-tosyl oxime (529 mg, 0.85 mmol, 1.00 equiv) was dissolved in Et.sub.2O (6 mL) and cooled to 78 C. Ammonia (ca. 6 mL) was then introduced and the reaction mix was stirred at reflux for 4 h. The cooling bath was removed and the volatiles were removed. The residue was suspended in diethyl ether and filtered. The filtrate was concentrated. MeOH (10 mL) was added and removed under reduced pressure (2) to remove residual ammonia. The residue was dissolved in MeOH (10 mL) and combined with NEt.sub.3 (0.6 mL, 4.3 mmol, 5.0 equiv). The mixture was titrated with a solution of iodine in MeOH until a yellow-brown color persisted. The mix was diluted with water (200 mL) and sat. aq. sodium thiosulfate (2 mL). Extraction with EtOAc (350 mL), washing with brine (50 mL), drying over MgSO.sub.4, filtration and concentration followed by flash chromatography on silica afforded the title compound as light-yellow oil (211 mg, 0.46 mmol, 54%). .sup.1H NMR (300 MHz, CDCl.sub.3) 7.97 (dt, J=8.0, 1.0 Hz, 1H), 7.65 (d, J=7.7 Hz, 1H), 7.44-7.37 (m, 2H), 7.06 (td, J=7.8, 0.8 Hz, 1H), 6.93-6.88 (m, 2H), 4.89 (s, 2H), 4.68 (s, 2H), 3.82 (d, J=0.8 Hz, 3H).

f) 3-(2-(((4-Methoxybenzyl)oxy)methyl)-3-((trimethyl silyl)ethynyl)phenyl)-3-(trifluoromethyl)-3H-diazirine

(34) ##STR00023##

(35) 3-(3-odo-2-(((4-methoxybenzyl)oxy)methyl)phenyl)-3-(trifluoromethyl)-3H-diazirine (196 mg, 0.424 mmol, 1.00 equiv) was combined with DMF (1.4 mL, degassed by the freeze-pump-thaw method), PdCl.sub.2(PPh.sub.3).sub.2(30 mg, 0.042 mmol, 0.10 equiv), CuI (16 mg, 0.085 mmol, 0.20 equiv) and NEt.sub.3 (0.12 mL, 0.85 mmol, 2.0 equiv). Trimethylsilylacetylene (89 L, 0.64 mmol, 1.5 equiv) was added and the mixture was stirred at rt for 20 min. The reaction mixture was diluted with 5% aq. LiCl and extracted with diethyl ether. The organics were washed with 5% aq. LiCl and brine, dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (2% EtOAc in hexanes) afforded the title compound as yellow oil (146 mg, 0.34 mmol, 80%). HRMS (ESI.sup.+) 450.1819 (M+NH.sub.4.sup.+).

g) 3-(3-Ethynyl-2-(((4-methoxybenzyl)oxy)methyl)phenyl)-3-(trifluoromethyl)-3H-diazirine

(36) ##STR00024##

(37) 3-(2-(((4-Methoxybenzyl)oxy)methyl)-3-((trimethyl silyl)ethynyl)phenyl)-3-(trifluoromethyl)-3H-diazirine (146 mg, 0.338 mmol, 1.00 equiv) was dissolved in MeOH (1 mL) and K.sub.2CO.sub.3 (52 mg, 0.38 mmol, 1.1 equiv) was added. After 1.5 h, sat. aq. NH.sub.4Cl was added the mixture was extracted with Et.sub.2O (330 mL). The organics were washed with brine, dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (3% EtOAc in hexanes) afforded the title compound as yellow oil. HRMS (ESI.sup.+) 383.0978 (M+Na.sup.+).

h) 2-Ethynyl-6-(3-(trifluoromethyl)-3H-diazirin-3-yl)benzyl methanesulfonate

(38) ##STR00025##

(39) 3-(3-Ethynyl-2-(((4-methoxybenzyl)oxy)methyl)phenyl)-3-(trifluoromethyl)-3H-diazirine (318 mg, 0.883 mmol, 1.00 equiv) combined with CH.sub.2Cl.sub.2 (8 mL) and H.sub.2O (0.8 mL) at 0 C. DDQ (301 mg, 1.32 mmol, 1.50 equiv) was added and it was stirred until TLC indicated full consumption of starting material. Sat. aq. sodium bicarbonate was added and the mix was extracted with CH.sub.2Cl.sub.2. The organics were dried over MgSO.sub.4, filtered and concentrated. Filtration over a plug of silica (20% EtOAc in hexanes) afforded a mixture of intermediate benzyl alcohol and p-anisaldehyde. The mixture was dissolved in CH.sub.2Cl.sub.2 (8 mL) and cooled to 0 C. NEt.sub.3 (0.18 mL, 1.3 mmol, 1.5 equiv) was added followed by MsCl (76 L, 0.97 mmol, 1.1 equiv). After 20 min, the reaction was quenched by the addition of sat. aq. sodium bicarbonate, extracted with CH.sub.2Cl.sub.2, dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (15% EtOAc in hexanes) afforded the title compound as colorless oil (244 mg, 0.767 mmol, 87%). The material turned red upon standing and solidified in the freezer. HRMS (ESI.sup.+) 341.0178 (M+Na.sup.+).

i) 5-(Difluoro(phenyl)methyl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7(4H)-one

(40) ##STR00026##

(41) In analogy to the procedure described for the synthesis of 5-(difluoro(phenyl)methyl)-3-(2-(trifluoromethyl)benzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7(4H)-one (example 2, step b) the title compound was prepared from 5-amino-1-(4-methoxybenzyl)-1H-1,2,3-triazole-4-carboxamide (CAS 133992-53-7, 2.0 g, 8.1 mmol, 1.0 equiv) and 2,2-difluoro-2-phenylacetonitrile and isolated as colorless solid (2.0 g, 5.2 mmol, 65%). .sup.1H NMR (400 MHz, DMSO) 13.57 (s, 1H), 7.75-7.66 (m, 2H), 7.64-7.53 (m, 3H), 7.27 (d, J=8.4 Hz, 2H), 6.88 (d, J=8.2 Hz, 2H), 5.64 (s, 2H), 3.72 (s, 3H).

j) 7-Chloro-5-(difluoro(phenyl)methyl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine

(42) ##STR00027##

(43) In analogy to the procedure described for the synthesis of 3-((5-(tert-Butyl)-7-chloro-3H-[1,2,3]triazolo[4,5-d]pyrimidin-3-yl)methyl)-4-methyl-1,2,5-oxadiazole (example 1, step a) the title compound was prepared from 5-(Difluoro(phenyl)methyl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7(4H)-one and isolated as colorless solid (1.21 g, 3.01 mmol, 93%). HRMS (ESI.sup.+) 402.0928 (M+H.sup.+).

k) 5-(Difluoro(phenyl)methyl)-7-(3,3-difluoropyrrolidin-1-yl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine

(44) ##STR00028##

(45) In analogy to the procedure described for the synthesis of 5-tert-butyl-3-[(4-methyl-1,2,5-oxadiazol-3-yl)methyl]-7-(1,2,5-triazaspiro[2.4]hept-1-en-5-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (example 1, step d) the title compound was prepared from 7-chloro-5-(difluoro(phenyl)methyl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (622 mg, 1.55 mmol, 1.00 equiv) and 3,3-difluoropyrrolidine hydrochloride (244 mg, 1.70 mmol, 1.10 equiv) and isolated as colorless solid (600 mg, 1.27 mmol, 82%). HRMS (ESI.sup.+) 473.1707 (M+H.sup.+).

l) 5-(Difluoro(phenyl)methyl)-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine

(46) ##STR00029##

(47) 5-(Difluoro(phenyl)methyl)-7-(3,3-difluoropyrrolidin-1-yl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (200 mg. 0.423 mmol. 1.00 equiv) was combined with anisole (1.40 mL, 12.8 mmol, 30.3 equiv) and trifluoroacetic acid (6.5 mL) and heated at 65 C. for 5 h. After removal of the volatiles, the residue was taken up in EtOAc (50 mL) and washed with aq. NaOH (1 M, 310 mL). The aqueous phase was backextracted with EtOAc (220 mL). The combined organics were washed with brine, dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (50% EtOAc in hexanes to 100%) afforded product contaminated with an unidentified byproduct. The solid was triturated with EtOH and filtered to leave a tan solid. The washings were concentrated and the residue was triturated with 20% EtOAc in hexanes. The suspension was filtered and the filtercake washed with the same solvent mixture to give another crop of the product (74 mg in total, 0.21 mmol, 50%). HRMS (ESI.sup.+) 353.1136 (M+H.sup.+).

m) 5-[Difluoro(phenyl)methyl]-7-(3,3-difluoropyrrolidin-1-yl)-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidine

(48) In analogy to the procedure described for the synthesis of 5-tert-butyl-2-({2-chloro-4-[3-(trifluoromethyl)-3H-diaziren-3-yl]phenyl}methyl)-7-(3,3-difluoropyrrolidin-1-yl)-2H-[1,2,3]triazolo[4,5-d]pyrimidine (example 1, step d) the title compound was prepared from 5-(difluoro(phenyl)methyl)-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (23 mg, 0.065 mmol, 1.0 equiv) and 2-ethynyl-6-(3-(trifluoromethyl)-3H-diazirin-3-yl)benzyl methanesulfonate (27 mg, 0.085 mmol, 1.3 equiv) and isolated as light-red oil (19 mg, 0.033 mmol, 51%). HRMS (ESI.sup.+) 575.1538 (M+H.sup.+).

Example 5

5-tert-Butyl-7-(3,3-difluoropyrrolidin-1-yl)-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidine

(49) ##STR00030##

(50) 5-tert-Butyl-7-(3,3-difluoropyrrolidin-1-yl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (CAS 1438465-59-8, 23 mg, 0.072 mmol, 1.0 equiv) and 2-ethynyl-6-(3-(trifluoromethyl)-3H-diazirin-3-yl)benzyl methanesulfonate (24 mg, 0.085 mmol, 1.2 equiv) were dissolved in DMF (0.5 mL). Trimethylamine (20 L, 0.15 mmol, 2.0 equiv) was added and it was stirred overnight at room temperature. The reaction mixture was diluted with EtOAc (60 mL), washed with 5% aq. LiCl (220 mL) and brine (120 mL), dried over MgSO.sub.4, filtered and concentrated. Flash chromatography on silica (5% EtOAc in hexanes) afforded the title compound as colorless oil (13 mg, 0.026 mmol, 36%). HRMS (ESI.sup.+) 505.1882 (M+H.sup.+).

Example 6

(3S)-1-[5-tert-Butyl-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol

(51) ##STR00031##

(52) (3S)-1-(5-tert-Butyl-3H-triazolo[4,5-d]pyrimidin-7-yl)pyrrolidin-3-ol (23 mg, 0.088 mmol, 1.20 equiv) and 2-ethynyl-6-(3-(trifluoromethyl)-3H-diazirin-3-yl)benzyl methanesulfonate (23 mg, 0.072 mmol, 1.00 equiv) were dissolved in DMF (0.5 mL). Triethylamine (15 L, 0.11 mmol, 1.5 equiv) was added and it was stirred overnight. The reaction mixture was diluted with EtOAc (60 mL), washed with 5% aq. LiCl (220 mL) and brine (120 mL), dried over MgSO.sub.4, filtered and concentrated. The crude was purified by flash chromatography on silica (30% EtOAc in hexanes+5% AcOH). Fractions containing product were pooled, washed with sat. NaHCO.sub.3 and brine, dried over MgSO.sub.4, filtered and concentrated to yield the title compound as colorless oil (10 mg, 0.021 mmol, 29%). HRMS (ESI.sup.+) 485.2015 (M+H.sup.+).

Example 7

(3S)-1-[5-[Difluoro(phenyl)methyl]-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol

(53) ##STR00032##

a) (S)-1-(5-(Difluoro(phenyl)methyl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl)pyrrolidin-3-ol

(54) ##STR00033##

(55) In analogy to the procedure described for the synthesis of 5-(Difluoro(phenyl)methyl)-7-(3,3-difluoropyrrolidin-1-yl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (example 4, step k) the title compound was prepared from 7-chloro-5-(difluoro(phenyl)methyl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidine (272 mg, 0.677 mmol, 1.00 equiv) and (S)-pyrrolidin-3-ol (65 mg, 0.75 mmol, 1.1 equiv) and isolated as colorless foam (291 mg, 0.643 mmol, 95%). HRMS (ESI.sup.+) 453.1850 (M+H.sup.+).

b) (S)-1-(5-(Difluoro(phenyl)methyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl)pyrrolidin-3-ol

(56) ##STR00034##

(57) (S)-1-(5-(Difluoro(phenyl)methyl)-3-(4-methoxybenzyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl)pyrrolidin-3-ol (141 mg, 0.312 mmol) was dissolved in trifluoroacetic acid (4.38 mL) and heated to 70 C. for 3 h. LCMS indicated the formation of product and of the respective trifluoroacetyl ester. After removal of the volatiles the residue was dissolved in MeOH (3 mL) and THF (3 mL). K.sub.2CO.sub.3 (215 mg, 1.59 mmol, 5.0 equiv) was added and it stirred for 30 minutes. LCMS indicates mainly desired product and a small amount of both isomers of the starting material, presumably due to non-selective reaction of the desired product with benzyltrifluoroacetate as alkylating agent. The reaction mix was neutralized with dilute HCl and concentrated. Flash chromatography on silica (5% MeOH in EtOAc to 10% to 30%) yielded a colorless solid (220 mg). The material was partitioned between EtOAc and sat. NaHCO.sub.3. The aq. phase was removed. The organic phase was washed with brine, dried over MgSO.sub.4, filtered and concentrated to give the title compound as yellowish solid (69 mg, 0.21 mmol, 67%).

c) (3S)-1-[5-[Difluoro(phenyl)methyl]-2-[[2-ethynyl-6-[3-(trifluoromethyl)diazirin-3-yl]phenyl]methyl]triazolo[4,5-d]pyrimidin-7-yl]pyrrolidin-3-ol

(58) (S)-1-(5-(Difluoro(phenyl)methyl)-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7-yl)pyrrolidin-3-ol (32 mg, 0.096 mmol, 1.0 equiv) and 2-ethynyl-6-(3-(trifluoromethyl)-3H-diazirin-3-yl)benzyl methanesulfonate (31 mg, 0.097 mmol, 1.0 equiv) were dissolved in DMF (0.5 mL). DIPEA (25 L, 0.15 mmol, 1.5 equiv) was added and the mixture was stirred overnight at room temperature. The reaction mixture was diluted with EtOAc (50 mL), washed with 5% aq. LiCl (220 mL) and brine (120 mL), dried over MgSO.sub.4, filtered and concentrated. Preparative TLC (20% EtOAc in hexanes+20% AcOH) afforded the title compound as colorless wax (24 mg, 0.043 mmol, 45%). HRMS (ESI.sup.+) 555.1677 (M+H.sup.+).

Example 8

(59) Pharmacological Tests

(60) The following tests were carried out in order to determine the activity of the compounds of formula (I):

(61) Radioligand Binding Assay

(62) The affinity of the compounds of the invention for cannabinoid receptors was determined using recommended amounts of membrane preparations (PerkinElmer) of human embryonic kidney (HEK) cells expressing the human CNR1 or CNR2 receptors in conjunction with 1.5 or 2.6 nM [3H]-CP-55,940 (Perkin Elmer) as radioligand, respectively. Binding was performed in binding buffer (50 mM Tris, 5 mM MgCl.sub.2, 2.5 mM EDTA, and 0.5% (wt/vol) fatty acid free BSA, pH 7.4 for CB1 receptor and 50 mM Tris, 5 mM MgCl.sub.2, 2.5 mM EGTA, and 0.1% (wt/vol) fatty acid free BSA, pH 7.4 for CB2 receptor) in a total volume of 0.2 mL for 1 h at 30 C. shaking. The reaction was terminated by rapid filtration through microfiltration plates coated with 0.5% polyethylenimine (UniFilter GF/B filter plate; Packard). Bound radioactivity was analyzed for Ki using nonlinear regression analysis (Activity Base, ID Business Solution, Limited), with the Kd values for [.sup.3H]CP55,940 determined from saturation experiments. The compounds of formula (I) show an excellent affinity for the CB2 receptor with affinities below 10 M, more particularly of 1 nM to 3 M and most particularly of 1 nM to 100 nM.

(63) The compounds according to formula (I) have an activity in the above assay (Ki) particularly of 0.5 nM to 10 M, more particularly of 0.5 nM to 3 M and most particularly of 0.5 nM to 100 nM.

(64) All compounds are CB2 binders with Ki values below 3 uM and selectivity versus CB1 in the corresponding assay of at least 4 fold.

(65) TABLE-US-00001 human CB2 Ki human CB1 Ki Example [M] [M] 1 2.3439 >10.000 2 0.9325 >10.000 3 2.8611 >10.000 4 1.0738 >10.000 5 0.0814 0.583 6 0.0992 >10.000 7 0.3579 5.459

(66) cAMP Assay

(67) CHO cells expressing human CB1 or CB2 receptors are seeded 17-24 hours prior to the experiment 50.000 cells per well in a black 96 well plate with flat clear bottom (Corning Costar #3904) in DMEM (Invitrogen No. 31331), 1 HT supplement, with 10% fetal calf serum and incubated at 5% CO.sub.2 and 37 C. in a humidified incubator. The growth medium was exchanged with Krebs Ringer Bicarbonate buffer with 1 mM IBMX and incubated at 30 C. for 30 min. Compounds were added to a final assay volume of 100 L and incubated for 30 min at 30 C. Using the cAMP-Nano-TRF detection kit the assay (Roche Diagnostics) was stopped by the addition of 50 L lysis reagent (Tris, NaCl, 1.5% Triton X100, 2.5% NP40, 10% NaN.sub.3) and 50 L detection solutions (20 M mAb Alexa700-cAMP 1:1, and 48 M Ruthenium-2-AHA-cAMP) and shaken for 2 h at room temperature. The time-resolved energy transfer is measured by a TRF reader (Evotec Technologies GmbH), equipped with a ND:YAG laser as excitation source. The plate is measured twice with the excitation at 355 nm and at the emission with a delay of 100 ns and a gate of 100 ns, total exposure time 10 s at 730 (bandwidth 30 nm) or 645 nm (bandwidth 75 nm), respectively. The FRET signal is calculated as follows: FRET=T730-Alexa730-P(T645-B645) with P=Ru730-B730/Ru645-B645, where T730 is the test well measured at 730 nM, T645 is the test well measured at 645 nm, B730 and B645 are the buffer controls at 730 nm and 645 nm, respectively. cAMP content is determined from the function of a standard curve spanning from 10 M to 0.13 nM cAMP.

(68) EC.sub.50 values were determined using Activity Base analysis (ID Business Solution, Limited). The EC.sub.50 values for a wide range of cannabinoid agonists generated from this assay were in agreement with the values published in the scientific literature.

(69) -Arrestin Translocation Assay-PathHunter (DiscoveRx)

(70) PathHunter 3-arrestin CHO-K1 CNR1 cell line (catalog number #93-0200C2) and the -arrestin CHO-K1 CNR2 cell line (catalog number #93-0706C2) were purchased from DiscoveRx Corporation. The cell line was engineered to express the 3-galactosidase EA fragment fused to -arrestin and the ProLink complementary peptide fused to the target receptor. The PathHunter protein complementation assay (DiscoveRx Corporation #93-0001) was performed according to the manufacturer's protocol. Assay plates were seeded containing 7500 (CNR1) and 10000 (CNR2) cells in 384 well plates (Corning Costar #3707, white, clear bottom) in 20 L cell plating reagent 2 (Discoverx #93-0563R2A). After incubation at 37 C. (5% CO.sub.2, 95% relative humidity) overnight, 5 L of test compound was added (1% final DMSO concentration) and the incubation continued at 30 C. for 90 min. Detection reagent (12 L) was then added and the incubation continued at room temperature for 60 min. Plates were then analyzed for a chemiluminescent signal using a Victor .sup.3V reader (Perkin Elmer).

Example A

(71) Film coated tablets containing the following ingredients can be manufactured in a conventional manner:

(72) TABLE-US-00002 Ingredients Per tablet Kernel: Compound of formula (I) 10.0 mg 200.0 mg Microcrystalline cellulose 23.5 mg 43.5 mg Lactose hydrous 60.0 mg 70.0 mg Povidone K30 12.5 mg 15.0 mg Sodium starch glycolate 12.5 mg 17.0 mg Magnesium stearate 1.5 mg 4.5 mg (Kernel Weight) 120.0 mg 350.0 mg Film Coat: Hydroxypropyl methyl cellulose 3.5 mg 7.0 mg Polyethylene glycol 6000 0.8 mg 1.6 mg Talc 1.3 mg 2.6 mg Iron oxide (yellow) 0.8 mg 1.6 mg Titan dioxide 0.8 mg 1.6 mg

(73) The active ingredient is sieved and mixed with microcrystalline cellulose and the mixture is granulated with a solution of polyvinylpyrrolidone in water. The granulate is then mixed with sodium starch glycolate and magnesium stearate and compressed to yield kernels of 120 or 350 mg respectively. The kernels are lacquered with an aq. solution/suspension of the above mentioned film coat.

Example B

(74) Capsules containing the following ingredients can be manufactured in a conventional manner:

(75) TABLE-US-00003 Ingredients Per capsule Compound of formula (I) 25.0 mg Lactose 150.0 mg Maize starch 20.0 mg Talc 5.0 mg

(76) The components are sieved and mixed and filled into capsules of size 2.

Example C

(77) Injection solutions can have the following composition:

(78) TABLE-US-00004 Compound of formula (I) 3.0 mg Polyethylene glycol 400 150.0 mg Acetic acid q.s. ad pH 5.0 Water for injection solutions ad 1.0 ml

(79) The active ingredient is dissolved in a mixture of Polyethylene glycol 400 and water for injection (part). The pH is adjusted to 5.0 by addition of acetic acid. The volume is adjusted to 1.0 ml by addition of the residual amount of water. The solution is filtered, filled into vials using an appropriate overage and sterilized.