1-Bromo-3-methylbutane → (4s,7r)-2-(2,4-Difluoro-phenyl)-7,8,8-trimethyl-1-(3-methyl-butyl)-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one

Participants

Reaction Conditions

Reaction Steps

A mixture of (4S,7R)-2-(2,4-difluoro-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (Intermediate 14; 600 mg, 1.97 mmol), tetrabutylammonium iodide (770 mg, 2.1 mmol) and 1-bromo-3-methyl-butane (2 mL, 16.7 mmol) in dimethylformamide (6 mL) was heated in an oil-bath at 120° C. for 18 h. The solvent was evaporated and dichloromethane (75 mL) was added. The solution was washed with water (5×20 mL) and aqueous sodium thiosulfate (20 mL), dried (magnesium sulfate), filtered, and evaporated. The residue was purified using an ISCO 40 g column, eluting with 20-90% ethyl acetate/hexanes to give (4S,7R)-2-(2,4-difluoro-phenyl)-7,8,8-trimethyl-1-(3-methyl-butyl)-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (204 mg, 28%) as a white solid. ES(+)-MS (M+H) 375.

Provenance & Evidence