Catalyst-Free, Rapid Synthesis of Fused Bicyclic Thiazolo-Pyrimidine and Pyrimido-Thiazine Derivatives by a Microwave-Assisted Method.

The present investigation deals with the rapid microwave-assisted synthesis of compounds containing fused bicyclic systems. Dihydropyrimidines obtained via a microwave-assisted Biginelli reaction were treated with dibromo alkanes under microwave conditions to yield thiazolo-pyrimidine and pyrimido-thiazine systems. The usefulness of this method lies in carrying out the reaction without a catalyst and solvent in a shorter time. The reaction was successfully extended to develop fused systems from benzimidazole-2-thiol. [ABSTRACT FROM AUTHOR]