Diversity-Oriented Expedient Route for the Synthesis of 3-Tetrahydropyrimidinyl-Coumarins via MCR.

ABSTRACTA practical, mild, and high-yielding synthetic approach for the synthesis of unknown tetrahydropyrimidinyl substituted 3-coumarins as hybrid scaffolds, potentially useful new chemical entities (NCEs), via metal- and catalyst-free multicomponent cyclization is described. The enhanced nucleophilicity of 3-amino coumarins versus 4-amino coumarin is explained via the difference in 13C NMR δ values (Δδ) of vinylic carbons. X-ray crystal analysis defines the structure of a representative set of example.