A Facile Method for the Production of D-p-Hydroxyphenylglycine. Asymmetric Transformation of DL-p-Hydroxyphenylglycine Using (+)-1-Phenylethanesulfonic Acid

Article abstract of DOI:10.1246/bcsj.60.4321

A practical method for the production of D-p-hydroxyphenylglycine, useful as a starting material for preparing semisynthetic penicillins or cephalosporins, has been developed.The diastereomeric salts of DL-p-hydroxyphenylglycine with (+)-1-phenylethanesulfonic acid as a resolving agent, were efficiently resolved into less soluble D-p-hydroxyphenylglycine (+)-1-phenylethanesulfonate and soluble L-HPG * (+)-PES by the fractional crystallization of its salts in aqueous solution.The soluble L-HPG * (+)-PES could be easily epimerized into DL-HPG * (+)-PES by heating it with water containing a 0.1 molar equivalent of free DL-HPG in an autoclave.When the fractional crystallization of DL-HPG with (+)-PES was simultaneously carried out under the epimerizing conditions, the DL-HPG * (+)-PES was transformed into D-HPG * (+)-PES in up to 90percent yield.The present asymmetric transformation should be a suitable method for preparing D-HPG in a large scale.