Preparation process of (6r)-tetrahydro-l-biopterin

Abstract From the Canadian patent

6R)-Tetrahydro-L-biopterin of the following formula:, is prepared by catalytically reducing L-erythrobiopterin or an acyl derivative thereof in the presence of an amine, at pH 10 - 13 and with a platinum-base catalyst and when one or more acyl groups still remain then removing the acyl groups. (6R)-Tetrahydro-Lbiopterin is effective for the treatment of certain serious neuroses and malignant hyperphenylalaninemia. The present invention has succeeded in preparing (6R)tetrahydro-L-biopterin at a high asymmetric ratio R/S and moreover with a high yield. Since the process of this invention makes use of an amine as a base the, process is free from admixture of any inorganic salt and can hence …