Benzyl Bromide → (4r,7s)-1-Benzyl-2-(2-chloro-4-fluoro-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one

Participants

Reaction Conditions

Reaction Steps

A mixture of (4R,7S)-2-(2-chloro-4-fluoro-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (Intermediate 43; 150 mg, 0.47 mmol), tetrabutylammonium iodide (174 mg, 0.47 mmol) and benzyl bromide (223 μL, 1.9 mmol) in dimethylformamide (3 mL) was heated at 80° C. overnight and then stirred at room temperature over the weekend. The solvent was evaporated and dichloromethane (50 mL) was added. The solution was washed with water (2×20 mL), saturated aqueous sodium thiosulfate (20 mL), and brine (20 mL), dried (magnesium sulfate), filtered, concentrated, purified by chromatography, eluting with 60-70% ethyl acetate/petroleum ether, and dried under high vacuum overnight to give (4R,7S)-1-benzyl-2-(2-chloro-4-fluoro-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (92 mg, 38%) as a light tan solid. APCI(+)-MS (M+H) 411.

Provenance & Evidence