Dimethyl Sulfoxide → tert-butyl (2S)-2-formylpyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

At −78° C., a solution of dimethylsulphoxide (7.06 ml, 0.099 mol) in dichloromethane (10 ml) was added dropwise to a solution of oxalyl chloride (6.40 ml, 0.075 mol) in dichloromethane (15 ml). The reaction mixture was stirred for 20 min at −78° C. A solution of (S)-1-(tert-butoxycarbonyl)-2-pyrrolidinemethanol (10 g, 0.050 mol) in dichloromethane (50 ml) was added. The reaction mixture was stirred for 20 min at −78° C. Triethylamine (27.7 ml, 0.199 mol) was added. The reaction mixture was stirred for 10 min at −78° C. and then warmed to room temperature. It was washed with a 10% aqueous solution of sodium hydrogen sulphate (60 ml). The aqueous phase was extracted with dichloromethane (30 ml). The combined organic layers were washed with a saturated aqueous solution of sodium hydrogen carbonate (100 ml) and dried over magnesium sulphate. The solvent was removed in vacuo, to give 11.2 g of crude (S)-2-formylpyrrolidine-1-carboxylic acid tert-butyl ester, which was used for the next step without purification.

Provenance & Evidence