Benzyl Bromide → HCID 57941527, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of (4S,7R)-2-(4-methoxy-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (Intermediate 40; 300 mg, 1.0 mmol), tetrabutylammonium iodide (371 mg, 1.0 mmol) and benzyl bromide (478 μL, 4.0 mmol) in dimethylformamide (10 mL) was heated at ˜100° C. overnight. The solvent was evaporated. Dichloromethane (150 mL) was added and the solution was washed with brine (150 mL), saturated aqueous sodium thiosulfate (150 mL; 50% w/v), saturated aqueous sodium hydrogen carbonate (150 mL) and brine (150 mL). The solution was dried (sodium sulfate), filtered, evaporated, and purified using a Biotage 40S system, eluting with 0.5-2% methanol/dichloromethane to give a partially purified product that still contained some tetrabutylammonium iodide (according to 1H NMR). The solid was dissolved in dichloromethane, washed with saturated sodium thiosulfate and brine, and then evaporated to dryness. The solid was passed through a plug of silica, eluting with 0-5% methanol/dichloromethane, to give (4S,7R)-1-Benzyl-2-(4-methoxy-phenyl)-7,8,8-trimethyl-1,2,4,5,6,7-hexahydro-4,7-methano-indazol-3-one (54.5 mg, 14%). APCI(+)-MS (M+H) 389.

Provenance & Evidence