A efficient protocol for the synthesis of thioamides in [DBUH][OAc] at room temperature

Abstract

A novel, simple and eco-friendly method to synthesize thioamides from aryl nitriles and sodium sulfide (Na₂S·9H₂O) catalyzed by 1,8-diazabicyclo[5,4,0]undec-7-enium acetate ([DBUH][OAc]) ionic liquid (IL) at room temperature was developed in this paper. In this reaction, readily available inorganic salt (Na₂S·9H₂O) serves as the sulfur source, and various functional groups of aryl nitriles were well tolerated at room temperature. In addition, the products were easily separated from the IL which could be reused at least five times without considerable loss of its activity and applied in the green, concise synthesis of ethionamide.