One-Step Synthesisof Thieno[2,3‑ d ]pyrimidin-4(3 H )‑ones via a Catalytic Four-Component Reaction of Ketones,Ethyl Cyanoacetate, S 8 , and Formamide

Thieno[2,3-d]pyrimidin-4(3H)-ones are important pharmacophores that have 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.