Dimethyl Sulfoxide → 1-[1-(Tert-butoxycarbonyl)-4-piperidylmethyl]-4-[4-formylbenzenesulfonyl]-2-piperazinone

Participants

Reaction Conditions

Reaction Steps

To a solution of oxalyl chloride (0.70 ml) in dichloromethane (60 ml) was added dropwise at −70° C. a solution of dimethylsulfoxide (0.85 ml) in dichloromethane (10 ml). Ten minutes later, to the mixture was added dropwise a solution of 1-[1-(tert-butoxycarbonyl)-4-piperidylmethyl]-4-[4-(hydroxymethyl)benzenesulfonyl]-2-piperazinone (1.87 g) in dichloromethane (20 ml), and the mixture was stirred at about −65° C. for 1 hour. To the mixture was added triethylamine (2.79 ml), and the mixture was stirred at −60° C. to −30° C. for 2 hours. The reaction solution was diluted with dichloromethane, washed with water and saturated brine, dried and concentrated, and the the residue was purified with silica gel column chromatography (ethyl acetate). Precipitated crystals were washed with ether to give colorless crystals of 1-[1-(tert-butoxycarbonyl)-4-piperidylmethyl]-4-[4-formylbenzenesulfonyl]-2-piperazinone (2.02 g).

Provenance & Evidence