Abstract

GREEN APPROACH TO SYNTHESIS OF NOVEL SUBSTITUTED 8HPYRANO [2, 3-e] BENZOXAZOL-8-ONES

B. Prasanna*, A. Sandeep, T. Revathi

ABSTRACT

A series of novel substituted 8H-pyrano-[2,3-e] benzoxazol-8-ones 5(a-e) were synthesized by condensation of the corresponding 8- amino-7-hydroxy-4-methyl coumarin 4 with substituted aromatic aldehydes 2(a-e) in the presence of 1-butyl-3-methylimidazolium tetrafluoroborate [bmim] BF4 as Ionic liquid. The intermediate 8- amino-7-hydroxy-4-methyl coumarin 4 has been accomplished by reduction of compound 8-nitro-7-hydroxy-4-methyl coumarin in Fe powder with NH4Cl.The chemical structures of the newly synthesized compounds were characterized by IR, NMR, mass spectral and CHN analysis. All the title compounds were subjected to in vitro antibacterial testing against two pathogenic strains and antifungal screening against two fungi. Among the tested compounds, 5b and 5c showed significant antibacterial and antifungal activities. Also the compound 5d showed significant antifungal activity against A niger.

Keywords: Coumarin, [bmim] BF4, oxazoles, iron powder, antimicrobial.