Dimethyl Sulfoxide → HCID 69214655, compound

Participants

Reaction Conditions

Reaction Steps

Add oxalyl chloride (2.52 mL, 28.9 mmol) to a solution of dimethyl sulfoxide (3.42 mL, 48.2 mmol) in dichloromethane (130 mL) at −78° C. After 15 minutes at −78° C., add (S)-2-(2-hydroxypropyl)piperazine-1,4-dicarboxylic acid di-tert-butyl ester 6.64 g, 19.3 mmol) in dichloromethane (20 mL). Stir the mixture for 1 hour at −78° C., add triethylamine (13.4 mL, 96.4 mmol) and warm to room temperature overnight. Dilute the mixture with saturated aqueous sodium bicarbonate and extract three times with dichloromethane. Combine the organic layers, dry over sodium sulfate and concentrate under reduced pressure. Purify by flash chromatography, eluting with a step gradient (100% dichloromethane to 5% 2N ammonia-methanol in dichloromethane), to obtain (S)-2-(2-oxo-propyl)-piperazine-1,4-dicarboxylic acid di-tert-butyl ester (5.77 g, 87%): mass spectrum (APCI): m/z=143.1 (M+1-2BOC).

Provenance & Evidence