Catalyst-free UV365-assisted synthesis of pyran annulated heterocyclic scaffolds and evaluation of their antibacterial activities

Abstract

A convenient and eco-friendly, one-pot synthetic protocol for pharmaceutically important pyran-based heterocyclic compounds is repeated herein. The reactions were carried out at room temperature in a water–ethanol solvent mixture under direct irradiation of UV365 light source in the absence of photocatalyst. The merits of the present protocol include mild and catalyst-free reactions, green procedures, and high yields. The added advantage of this protocol is that it can be applied for large-scale synthesis of various pyran-based heterocyclic compounds without employing any expensive catalyst. Also, in vitro antibacterial screening of pyran derivative was investigated against both Gram-positive Bacillus cereus (B. cereus) and Gram-negative bacteria Escherichia coli (E. coli).