Reaction Steps
A solution of (3R,4aR,12bS)-9-(4-fluorophenyl)-3-hydroxy-3-(trifluoromethyl)-1,2,3,4,4a,5,6,7,9,12b-decahydrobenzo[6,7]cyclohepta[1,2-f]indazole-12b-carbonitrile; compound with (3S,4aS,12bR)-9-(4-fluorophenyl)-3-hydroxy-3-(trifluoromethyl)-1,2,3,4,4a,5,6,7,9,12b-decahydrobenzo[6,7]cyclohepta[1,2-f]indazole-12b-carbonitrile (32, R1=4-Fluorophenyl, R3=Trifluoromethyl) (3.0 g, 6.77 mmol) in THF (60 mL) was cooled to about 0° C. under nitrogen. LiHMDS (1M solution in hexane, 8.12 mL, 8.12 mmol) was added dropwise, maintaining the reaction temperature below about 3° C. and the anion was stirred for an additional 10 min at 0° C. Triethylchlorosilane (1.72 mL, 10.2 mmol) was added and the reaction was stirred at about 0° C. for 6 h. The reaction was quenched by addition of sat. aq. NH4Cl (50 mL), and extracted with EtOAc (100 mL). The organic layer was dried over Na2SO4 and filtered. The filterate was treated with silica gel (10 g) and concentrated to dryness. The residue was purified on silica gel (120 g) using a gradient of 5-20% EtOAc in heptane. Product fractions were combined and concentrated to about 50 mL volume. Product was filtered off, rinsed with heptane (10 mL) and dried under reduced pressure to yield (3S,4aS,12bR)-9-(4-fluorophenyl)-3-((triethylsilyl)oxy)-3-(trifluoromethyl)-1,2,3,4,4a,5,6,7,9,12b-decahydrobenzo[6,7]cyclohepta[1,2-f]indazole-12b-carbonitrile; compound with (3R,4aR,12bS)-9-(4-fluorophenyl)-3-((triethylsilyl)oxy)-3-(trifluoromethyl)-1,2,3,4,4a,5,6,7,9,12b-decahydrobenzo[6,7]cyclohepta[1,2-f]indazole-12b-carbonitrile (39, R1=4-Fluorophenyl, R3=Trifluoromethyl) as a white solid (2.88 g, 76%); LC/MS, method 4, Rt=2.47 min, MS m/z 558 (M+H)+, 1H NMR (400 MHz, DMSO) δ 8.32 (d, J=0.8 Hz, 1H), 8.09 (s, 1H), 7.83-7.77 (m, 2H), 7.67 (s, 1H), 7.45-7.38 (m, 2H), 3.37-3.25 (m, 1H), 2.12-3.00 (m, 1H), 2.62-2.52 (m, 2H), 2.47-2.38 (m, 1H), 2.27-2.16 (m, 1H), 2.07-1.92 (m, 3H), 1.86-1.54 (m, 3H), 1.38-1.24 (m, 1H), 0.99-0.92 (m, 9H), 0.72-0.62 (m, 6H).
