Processes for producing B-halogeno-a-amino-carboxylic acids and phenylcysteine derivatives and intermediates thereof

摘要

An industrially advantageous method of producing beta-halogeno-alpha-aminocarboxylic acids is provided. Methods are also provided of producing optically active N-protected-S-phenylcysteines having high optical purity and of intermediates thereof, respectively, in which the above production method is utilized. A method of producing beta-halogeno-alpha-aminocarboxylic acids or salts thereof is disclosed which comprises halogenating the hydroxyl group of a beta-hydroxy-alpha-aminocarboxylic acid (in which the basicity of the amino group in alpha-position is not masked by the presence of a substituent on said amino group) or a salt thereof with an acid with a halogenating agent. A method of producing optically active N-protected-S-phenylcysteines represented by the general formula (3) or salts thereof is further disclosed which comprises applying the above production method to optically active serine or a salt thereof and then carrying out treatment with an amino-protecting agent and reaction with thiophenol under a basic condition.