Dimethyl Sulfoxide → (2R)-1-[3,5-bis(trifluoromethyl)benzoyl]-2-(3,4-dimethylbenzyl)-4-[2-(formylmethoxy)ethyl]piperazine

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of oxalyl chloride (151 mg) in dichloromethane (3 ml) was added dropwise a solution of dimethylsulfoxide (123 mg) in dichloromethane (0.25 ml) at −78° C. under nitrogen atmosphere. After 15 minutes, (2R)-1-[3,5-bis(trifluoromethyl)benzoyl]-2-(3,4-dimethylbenzyl)-4-[2-(2-hydroxyethoxy)ethyl]piperazine (317 mg) was added at the same temperature. After 15 minutes, the resulting mixture was stirred at −45° C. for 1 hour. Triethylamine (446 mg) was added at −45° C., and the whole was stirred at 0° C. for 20 minutes and then treated with aqueous solution of ammonium chloride (2 ml). The organic layer was separated and dried over magnesium sulfate. After evaporation of the solvent, the resulting residue was purified by column chromatography on silica gel using ethyl acetate as eluent to afford (2R)-1-[3,5-bis(trifluoromethyl)benzoyl]-2-(3,4-dimethylbenzyl)-4-[2-(formylmethoxy)ethyl]piperazine (171 mg).

Provenance & Evidence