Preparation of Some New Coumarin Derivatives with Biological Activity

Abstract

The reaction of 3-aminocoumarin(1) with benzoyl isothiocyanate gave 3- (3`-coumarinyl)-N-benzoyl thiourea (2).Compound (2) was cyclised into either 2-thioxo-1,3,5-trihydropyrimidine-4,6-dione derivative (3) or thiazolidin-4-one derivative (4). Alkylation of (1) using excess of benzyl chloride afforded N,N,N-tribenzyl-N-(coumarin-3-yl) ammonium chloride (5), also, treatment of (1) with 2-alkylthio-4-chloro-6-phenyl pyrimidine (6a,b) gave 3-((2-alkylthio-6-phenylpyrimidin4`-yl) amino) -2H-benzopyran-2-ones (7a,b). Condensation of (1) with aromatic aldehydes produced the Shiff-bases (8a-d). Each of compounds (8a-d) reacted with 4-hydroxycoumarin to give 3- {(substituted aryl)(coumarin-3`-yl amino) methyl}-4-hydroxycoumarin derivatives (9a-d). Reaction of (8a) with phenylmagnesium bromide afforded 2,2,4-triphenyl chroman derivative (10). Reaction of each compounds (8a-d) with maleic anhydride gave 3-(N-(coumarin-3`-yl)carbamoyl)prop-2-enoic acid (11) as the same product. Treatment of (11) with hydrazine hydrate and phenyl hydrazine in ethanol at room tempreature afforded the ring opening products (12a,b) respectively. The antimicrobial activity of the synthesized compounds was tested against Gram positive and Gram negative bacteria as well as fungi.