Dimethyl Sulfoxide → tert-Butyl 3-oxo-2-phenylpiperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a cooled (-60° C.) solution of oxalyl chloride (0.68 ml, 7.8 mmol) in dichloronmethane (17 ml) was added dimethyl sulphoxide (0.69 ml, 9.8 mmol) for 10 minutes before addition of (±)1-tert-butoxycarbonyl-3-hydroxy-2-phenylpiperidine (1.8 g, 6.5 mmol; prepared by the method described in European Patent Specification number 0 528 495-A) in dichloromethane (7 ml). The solution was stirred at -60° C. for 20 minutes, warmed to -30° C. and triethylamine (2.5 ml) added. The solution was warmed to room temperature then was washed with ice cold 10% aqueous citric acid solution (40 ml, twice), water and dried (MgSO4). After evaporation the residue was purified by chromatography on silica gel (eluting with hexane containing an increasing proportion of ethyl acetate up to 20%) to give the title compound.

Provenance & Evidence