A green chemical approach: a straightforward one-pot synthesis of 2-aminothiophene derivatives via Gewald reaction in deep eutectic solvents

Abstract

The synergic effect of choline chloride/urea as a deep eutectic solvent was investigated in the synthesis of 2-aminothiophene derivatives via a three-component cyclocondensation of a ketone or an aldehyde with activated nitriles and elemental sulfur catalyzed by NaOH as cheap and highly accessible base. The advantages of this catalytic protocol are eco-friendly, easy to set up, reusability, and a simple separation and purification of products without using chromatography in high yields at short times.