Hydrochloric Acid → methyl (2S)-2-[(2R)-2-aminopropanamido]-4-methylpentanoate hydrochloride

Participants

Reaction Steps

A solution of 7 g. of Nα -benzyloxycarbonyl-D-alanyl-L-leucine, methyl ester in 100 ml. of methanol and 22 ml. of 0.95 l N hydrogen chloride in methanol is stirred with 500 mg. of 20% palladium on carbon catalyst under hydrogen at one inch water pressure until thin layer chromatography of a sample shows complete conversion (three to six hours). The solution is filtered to remove the catalyst and is evaporated to a foam. Solution in chloroform, 50 ml., and precipitation by ethyl ether affords an oil which is collected and dried at 45° C. and 1 mm. pressure. The oil is used in the next step without further purification.

Provenance & Evidence