Acid-Mediated One-Pot Three-Component Tandem Cyclization: Access to Some New Series of Benzo[5,6]chromeno[2,3-d]pyrimidine Derivatives

An efficient one-pot synthesis of some new series of benzo[5,6]chromeno[2,3-d]pyrimidine derivatives is reported by the three-component condensation reaction of 2,3-dihydroxynaphthalene, 2-thiobarbituric acid and aromatic aldehydes using sulfuric acid as the catalyst in glacial acetic acid under reflux condition. This transformation apparently proceeds through Michael addition, intra-molecular heterocyclization and dehydration sequences. This protocol provides cleaner reaction profiles, good to high yields, operational simplicity, easy workup, readily accessible starting materials and not requires column chromatography for isolation of target products in pure form. An efficient one-pot synthesis of some new series of benzo[5,6]chromeno[2,3-d]pyrimidine derivatives is reported by the three-component condensation reaction of 2,3-dihydroxynaphthalene, 2-thiobarbituric acid and aromatic aldehydes using sulfuric acid as the catalyst in glacial acetic acid under reflux condition. This transformation apparently proceeds through Michael addition, intra-molecular heterocyclization and dehydration sequences. image