Abstract
Optical resolution of DL p-hydroxyphenylglycine was studied in order to develop a practi-cal method for the production of D-p-hydroxyphenylglycine useful as a starting material for preparing semisynthetic penicillin and cephalosporins. Among the various aromatic sul-fonates of DL p-hydroxyphenylglycine, the benzenesulfonate, the o-toluenesulfonate, the p-toluenesulfonate, the p-ethylbenzenesulfonate, the sulfosalicylate, and the 2-naphthol-6-sulfonate were easily resolved by a preferential crystallization procedure. The optically pure sulfonates of D-p-hydroxyphenylglycine were obtained in good yield and were easily con-verted to optically pure D-p-hydroxyphenylglycine without racemization. The undesired sulfonates of the L-isomer were readily racemized and could be reused for the resolution step. Industrial production of D-p-hydroxyphenylglycine by the present simple resolution method is considered to be very promising.
