Patent ID: 8324381

Claim:
A process for the preparation of valganciclovir or a pharmaceutically acceptable salt thereof, with triacetyl ganciclovir (V) as a starting material, said process comprising the following steps: a) selective hydrolysis of triacetyl ganciclovir of Formula V to monoacetyl ganciclovir of Formula Va, optionally in the presence of a first solvent, wherein the selective hydrolysis comprises reacting triacetyl ganciclovir of Formula V with an amine; b) reacting monoacetyl ganciclovir obtained from step (a), with CBZ Valine, with a coupling agent and a second solvent, to give compound of Formula VI; c) hydrolysis under basic conditions of compound of Formula VI; using an amine to give N-Benzyloxycarbonyl valganciclovir, d) hydrogenolysis in the presence of a catalyst, under acidic conditions of N-Benzyloxycarbonyl valganciclovir to give valganciclovir, and e) optionally converting valganciclovir to a pharmaceutically acceptable salt thereof.