Process for preparing ganciclovir derivatives

摘要

Intermediates of Formula (III) wherein P1 is hydrogen or an amino-protecting group, R is lower alkyl, allyl or aralkyl, and Z is hydrogen, lower alkyl, aryl or aralkyl; and Formula (VI) wherein P1 is hydrogen or an amino-protecting group, P2 is an amino protecting group, and Z is hydrogen, lower alkyl, aryl or aralkyl, are useful in a novel process for preparing the mono-L-valine ester of 2-(2-amino-1,6-dihydro-6-oxo-purin-9-yl)methoxy-1,3-propanediol (ganciclovir). The mono-L-valine ester of ganciclovir and its pharmaceutically acceptable salts are of value as antiviral agents with improved absorption.