Three-Component Reaction between 3‑Acetylcoumarins, Amines, and Elemental Sulfur: A Designed Approach to 3‑Amino‑4H‑thieno[3,2‑c]coumarins

In this work, a series of novel 3-amino-4H-thieno[3,2-c]coumarins were designed and synthesized by a one-pot, catalyst-free, and three-component reaction of 3-acetylcoumarins with amines and elemental sulfur. Readily available starting materials, simple heating conditions, facile installation of a sulfur atom into the molecule using S₈ as a sulfur source, acceptable functional group tolerance, and synthetically useful yields are some highlighted benefits of this process.