| 摘要 |
PURPOSE:To obtain easily the titled compound expected as an intermediate for medicines, by reacting a specific thiol with a readily available beta-chloroalanine in an aqueous solution of specific pH. CONSTITUTION:A thiol expressed by the formula R-SH (R represents 4C alkyl substituted by OH, carboxyl, lower alkoxycarbonyl, etc.) and beta-chloroalanine are reacted in an aqueous solution of 10-13pH, preferably 11-12pH to obtain the cysteine derivative expressed by formula. beta-chloroalanine is easily prepared by hydrolyzing alpha-amino-beta-chloropropionitrile with an acid. As for the thiol, mercaptoethanol, 3-mercapto-n-propanol, etc. are mentioned. The sufficient amount of the alkali to be present in the reaction system is 2-20 times the amount of the beta-chloroalanine.
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