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

In this work, a series of novel 3-amino-4 H -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 S 8 as a sulfur source, acceptable functional group tolerance, and synthetically useful yields are some highlighted benefits of this process.