Three-step process for the synthesis of favipiravir

Abstract

A three-step process has been developed for the synthesis of antiviral drug favipiravir (T-705) starting from a readily available ethylenediamine and diethyl 2-oxomalonate. The synthesis involves the formation of ethyl 3-hydroxypyrazine-2-carboxylate by direct condensation of ethylenediamine with diethyl 2-oxomalonate followed by amide formation and electrophilic fluorination. This approach not only consists of three steps but also ensures the usage of inexpensive and easily available starting materials. It is an alternative process that can replace bromination or nitration, POCl3 etc that are used in previous methods.