Facile synthesis of pyridopyrimidine and coumarin fused pyridine libraries over a Lewis base-surfactant-combined catalyst TEOA in aqueous medium

A highly convergent and efficient protocol, for the facile synthesis of a library of coumarin fused pyridine and pyridopyrimidine derivatives, has been developed by applying a Lewis base-surfactant-combined catalyst (LBSC) triethanolamine (TEOA). The method described has the benefits of operational simplicity and excellent yields of the targeted molecule. The LBSCs were found to form stable colloidal dispersions rapidly in the presence of reaction substrates in water, even when the substrates are solid. In light of the increased demand for reduction of organic solvents in industry, the surfactant aided Lewis base catalysis described here may have immense practical consequences in organic synthesis. This work may not only lead to environmentally benign systems but also will provide a newer aspect of organic chemistry in water.