Catalyst-Free One-Pot Three-Component Synthesis of Diversely Substituted 5-Aryl-2-oxo-/thioxo-2,3-dihydro-1-benzo[6,7]chromeno[2,3-]pyrimidine-4,6,11(5)-triones Under Ambient Conditions.

A simple, catalyst-free, straightforward, and highly efficient one-pot synthesis of pharmaceutically interesting diverse kind of a new series of functionalized 5-aryl-2-oxo-/thioxo-2,3-dihydro-1-benzo[6,7]chromeno[2,3-]pyrimidine-4,6,11(5)-triones () and substituted 5,5'-(1,4-phenylene)bis(2-oxo-/thioxo-2,3-dihydro-1-benzo[6,7]chromeno[2,3-]pyrimidine-4,6,11(5)-trione) derivatives () has been developed based on a three-component reaction between barbituric acid/,-dimethylbarbituric acid/2-thiobarbituric acid (), aromatic aldehydes (), and 2-hydroxy-1,4-naphthoquinone () in aqueous ethanol at room temperature (25-30 °C). The salient features of this protocol are mild reaction conditions, use of no catalyst, no need of column chromatographic purification, excellent yields, high atom economy, eco-friendliness, easy isolation of products, and reusability of reaction media.