Reaction Steps
Thionyl chloride (0.120 mL, 1.645 mmol) was added dropwise to a solution of (3R,4aR,12bR)-12b-ethyl-9-(4-fluorophenyl)-3-(trifluoromethyl)-1,2,3,4,4a,5,6,7,9,12b-decahydrobenzo[6,7]cyclohepta[1,2-f]indazol-3-ol (11, R1=4-Fluorophenyl, R2=Ethyl, R3=Trifluoromethyl) (0.0720 g, 0.161 mmol), pyridine (0.200 mL, 2.473 mmol), and toluene (0.300 mL) under a nitrogen atmosphere. The mixture was warmed to about 80° C. After about 4 h, the mixture was allowed to cool to rt. The volatiles were removed under reduced pressure. Saturated aq. NaHCO3 (2 mL) and EtOAc (5 mL) were added. The layers were separated and the aqueous layer was extracted with EtOAc (5 mL). The combined organics were dried over Na2SO4, filtered, and concentrated. The residue was purified on silica gel (80 g) using a gradient of 0-10% EtOAc in heptane. The fractions containing product were combined and concentrated under reduced pressure to afford a 2:1 mixture of (4aR,12bR)-12b-ethyl-9-(4-fluorophenyl)-3-(trifluoromethyl)-1,2,4a,5,6,7,9,12b-octahydrobenzo[6,7]cyclohepta[1,2-f]indazole (66, R1=4-Fluorophenyl, R2=Ethyl, R3=Trifluoromethyl) and (4 aR,12bR)-12b-ethyl-9-(4-fluorophenyl)-3-(trifluoromethyl)-1,4,4a,5,6,7,9,12b-octahydrobenzo[6,7]cyclohepta[1,2-f]indazole (65, R1=4-Fluorophenyl, R2=Ethyl, R3=Trifluoromethyl) (0.0599 g, 0.140 mmol) as a light yellow film. LC/MS, method 3, Rt=3.23 min, MS m/z 429 (M+H)+. Potassium osmate dihydrate (0.0040 g, 0.011 mmol) was added in one portion to a biphasic solution of a 2:1 mixture of (4aR,12bR)-12b-ethyl-9-(4-fluorophenyl)-3-(trifluoromethyl)-1,2,4a,5,6,7,9,12b-octahydrobenzo[6,7]cyclohepta[1,2-f]indazole (66, R1=4-Fluorophenyl, R2=Ethyl, R3=Trifluoromethyl) and (4aR,12bR)-12b-ethyl-9-(4-fluorophenyl)-3-(trifluoromethyl)-1,4,4a,5,6,7,9,12b-octahydrobenzo[6,7]cyclohepta[1,2-f]indazole (65, R1=4-Fluorophenyl, R2=Ethyl, R3=Trifluoromethyl) (0.0560 g, 0.131 mmol), THF (1.0 mL), and water (0.50 mL). NMO (0.046 g, 0.392 mmol) was added in one portion. After about 16 h, the mixture was warmed to about 40° C. After about 33 h, the mixture was allowed to cool to rt. Water (3 mL) was added. The solution was extracted with DCM (2×5 mL). The combined organics were dried over Na2SO4, filtered, and concentrated under reduced pressure. The material was dissolved in DCM/MeOH and 0.4 g of silica gel was added. The volatiles were removed under reduced pressure. The resulting solid was purified on silica gel (12 g) using a gradient of 0-20% EtOAc in heptane. The fractions containing product were combined and concentrated under reduced pressure to afford (2S,3R,4aR,12bR)-12b-ethyl-9-(4-fluorophenyl)-3-(trifluoromethyl)-1,2,3,4,4a,5,6,7,9,12b-decahydrobenzo[6,7]cyclohepta[1,2-f]indazole-2,3-diol (67, R1=4-Fluorophenyl, R2=Ethyl, R3=Trifluoromethyl) (0.0116 g, 19% yield) as an ivory solid. LC/MS, method 2, Rt=2.75 min, MS m/z 463 (M+H)+. 1H NMR (400 MHz, DMSO) δ 8.32 (s, 1H), 7.85 (s, 1H), 7.84-7.76 (m, 2H), 7.56 (s, 1H), 7.46-7.35 (m, 2H), 5.52 (s, 1H), 4.90 (d, J=6.7 Hz, 1H), 3.90-3.79 (m, 1H), 3.22-3.09 (m, 1H), 3.00-2.89 (m, 1H), 2.24-2.06 (m, 3H), 2.06-1.94 (m, 1H), 1.92-1.70 (m, 2H), 1.69-1.51 (m, 4H), 1.40-1.20 (m, 1H), 0.45 (t, J=7.3 Hz, 3H).
