Improved Synthesis of Antiviral Drug Valacyclovir Hydrochloride

A cost-effective and improved process was developed for the synthesis of the antiviral drug Valacyclovir hydrochloride 1. The process involves the Streglich condensation between 4 and 6 to obtain N-Phthalimide-L-Valine ester 5, which was deprotected by using 40% monomethylamine Overall, the chemistry has been developed and used to prepare Valacyclovir drug 1 in an overall yield of 61 %.