Citric Acid → HCID 69492169, compound

Participants

Reaction Steps

A solution of 0.57 g (2.3 mmol) of (S)-Boc-methionine in 5 ml of dichloromethane is treated at RT consecutively with 0.87 g (2.3 mmol) of O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium-hexafluorophosphate (HBTU), 0.50 g (2.1 mmol) of 4-benzyloxyaniline hydrochloride and 0.98 ml (5.7 mmol) of N-ethyl-diisopropylamine. The reaction mixture is stirred during 1 h at RT. For the working-up, the reaction mixture is diluted with dichloromethane and treated with 20 ml of an aqueous solution of citric acid (10%). The aqueous phase is re-extracted with dichloromethane, the organic phases combined, dried over sodium sulfate and evaporated under reduced pressure. For purification, the crude material obtained is chromatographed on silica gel using a 3:1 mixture of n-hexane and ethyl acetate as the eluent. There are obtained 0.74 g (82.5% of theory) of (S)-[1-(4-benzyloxy-phenylcarbamoyl)-3-methylsulfanyl-propyl]-carbamic acid tert-butyl ester as a white solid. MS: m/e=431 (M+H)+.

Provenance & Evidence