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

Abstract

In this work, a series of novel 3-amino-4Hthieno[3,2-c]coumarins were designed and synthesized by a onepot, 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.

Sulfur- and DABCO-Promoted Reaction between Alkylidene Rhodanines and Isothiocyanates: Access to Aminoalkylidene Rhodanines

“…Yavari et al reported the synthesis of spiropyrrolizidine-linked rhodanines through [3 + 2] cycloaddition reactions of azomethine ylides, prepared in situ from l -proline and acetylenic esters and alkylidene rhodanines . As a part of our ongoing studies directed toward developing practical and novel synthetic protocols for heterocycles, we decided to employ alkylidene rhodanines for the synthesis of novel rhodanine-based molecules …”

“… 9 As a part of our ongoing studies directed toward developing practical and novel synthetic protocols for heterocycles, we decided to employ alkylidene rhodanines for the synthesis of novel rhodanine-based molecules. 10 …”