Diversity-oriented expedient route for the synthesis of 3-tetrahydropyrimidinyl-coumarins via MCR

ABSTRACT

A 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.

GRAPHICAL ABSTRACT

KEYWORDS:

• Catalyst-free
• ¹³C NMR and nucleophilicity
• Mannich reaction
• MCR
• tetrahydropyrimidinyl-coumarins

Acknowledgment

The authors are thankful to the head of the Department of Chemistry, Saurashtra University, Rajkot, for providing facilities.