Process for the preparation of derivatives of ganciclovir.

PROCEDURE AND NOVEL INTERMEDIATE FOR THE PREPARATION OF ESTER L - monovaline OF 2- (2 - AMINO - 1.6 - DIHYDRO - 6 - OXO PURIN - 9 - IL) - METHOXY - 1,3 - propanediol (ganciclovir) and their pharmaceutically ACCEPTABLE. THIS PROCEDURE AND PROVIDE THE INTERIM monoester monoesterification with a derivative of L - valine, PRODUCING monocarboxylate monovalinate, which is hydrolysed selectively or enzymatic BASIC CONDITIONS GIVING ESTER monovaline ganciclovir with high yield and purity. THESE PRODUCTS ARE VALUABLE AS ANTIVIRAL AGENTS WITH IMPROVED ABSORPTION.