A process for preparing an optically active p-hydroxyphenyl-glycine or a salt thereof.

摘要

Optical resolution of a p-hydroxyphenylglycine salt such as p-hydroxyphenylglycine benzene sulphonate with simultaneous racemization of the undesired enantiomer thereof can be conducted by preferentially crystallizing out the desired enantiomer from a supersaturated solution of the racemic modification thereof in a lower aliphatic acid such as acetic acid in the presence of an aliphatic or aromatic aldehyde such as salicylaldehyde.