Synthesis of Thioureas, Thioamides, and Aza-Heterocycles via Dimethyl-Sulfoxide-Promoted Oxidative Condensation of Sulfur, Malonic Acids, and Amines

Malonic acid and derivatives have been well-known toundergo monodecarboxylationunder relatively mild conditions and have been exclusively used asa C-2 synthon. We report herein their new application asa C-1 synthon via double decarboxylation promoted by sulfurand dimethyl sulfoxide. In the presence of amines as nucleophiles,a wide range of thioureas and thioamides as well as N-heterocycles were obtained in good to excellent yields under mildheating conditions.

Automated summary

Malonic acid and its derivatives, known for undergoing monodecarboxylation under mild conditions as a C-2 synthon, have been found to have a new application as a C-1 synthon through double decarboxylation promoted by sulfur and dimethyl sulfoxide. In the presence of amines as nucleophiles, a wide range of thioureas, thioamides, and N-heterocycles are produced in good to excellent yields under mild heating conditions.