摘要:
DL- .alpha.-phenylglycine can be combined with benzene-sulfonic acid, p-ethylbenzenesulfonic acid or m-xylenesulfonic acid to give the salt. The salt of the racemate may be more soluble in a sulfuric acid solution than the salt of the optically active isomer by suitably choosing the concentration of the sulfuric acid solution, and then the optical resolution by fractional crystallization is carried out. The D- or L- .alpha.-phenylglycine sulfonate is easily liberated of the sulfonic acid portion to give optically active D- or L- .alpha.-phenylglycine.