Benzyl Bromide → HCID 15953817, compound

Participants

Reaction Steps

A solution of (4R,7S)-2-(2-fluoro-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (Intermediate 38; 890 mg, 3.11 mmol), terabutylammonium iodide (860 mg, 2.33 mmol) and benzyl bromide (1.7 mL, 14.3 mmol) in dimethylformamide (15 mL) was heated in an oil-bath at 100° C. for 3 h. The reaction mixture was cooled to room temperature and the solvent was evaporated. Dichloromethane (100 μL) was added and the solution was washed with water (5×25 mL), aqueous sodium thiosulfate (25 mL), and brine (25 mL), dried (magnesium sulfate, filtered, and evaporated. The residue was purified using an ISCO 120 g column, eluting with 60-100% ethyl acetate/hexanes. Fractions containing the product were concentrated and then co-evaporated with ether. Petroleum ether was added and the mixture was scratched to give a solid. The solvent was evaporated and the residue was co-evaporated three times with ethanol, and then dried under high vacuum at 65° C. and then at 75° C. to give (4R,7S)-1-benzyl-2-(2-fluoro-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (462 mg, 39%) as a pale yellow solid. ES(+)-MS (M+H) 377.

Provenance & Evidence