One-Step Synthesis of Thieno[2,3- d]pyrimidin-4(3 H)-ones via a Catalytic Four-Component Reaction of Ketones, Ethyl Cyanoacetate, S₈ and Formamide

Thieno[2,3-d]pyrimidin-4(3H)-ones are important pharmacophores that previously required a three step synthesis with two chromatography steps. We herein report a green approach to the synthesis of this pharmacologically important class of compounds via a catalytic four-component reaction using a ketone, ethyl cyanoacetate, S₈ and formamide. The reported reaction is characterized by step economy, reduced catalyst loading and easy purification.