A three-component reaction between 3-acetylcoumarins, six-membered cyclic secondary amines, and elemental sulfur: A straightforward approach to 3-hydroxy-2-amino-4H-thieno[3,2-c]coumarins.

In this work, we have developed a novel strategy for synthesizing functionalized thieno[3,2-c]coumarins starting from readily available 3-acetylcoumarins, six-membered cyclic secondary amines, and elemental sulfur under simple heating conditions. This multicomponent process demonstrated operational simplicity for installing a hydroxyl group and an amine scaffold onto the thieno[3,2-c]coumarin core. Interesting product structures, synthetically useful yields, and scalability are some notable features of this reaction.