Synthesis and Antimicrobial Activity of Some New Coumarin and Dicoumarol Derivatives

Phase transfer catalysis reaction of 4-hydroxy-6-methyl-2H-chromen-2-one with alkyl halides afforded C(4)oxygen alkylation products of 2H-chromen-2-one derivatives in appreciative yield, whereas with phenyl isothiocyanate gives the C(3)addition product of 4-hydroxy-6-methyl-2-oxo-N-phenyl-2H-chromene-3-carbothioamide, also one pot three component phase transfer reaction was investigated. Treatment of 4-hydroxy-6-methyl-2H-chromen-2-one with aromatic aldehydes in different molar ratios gives 3-arylidine and the dicoumarol derivatives.However pyrano chromene and pyrano pyridine were obtained by reaction of arylidine with ethyl acetoacetate through Michael cycloaddition reaction. The stability of pyrone ring in 3-arylidine and dicoumarol towards different nucleophilic reagents under reflux and/or fusion conditions has been studied by the action of, hydrazine hydrate, ammonium acetate, methyl amine andp-toluidine afforded compounds 1,2-bis(benzo[d][1,3]dioxol-5-ylmethylene)hydrazine, 1,2-bis(4-methoxybenzylidene)hydrazine and 2,6-bis((2,6-dihydroxy-3-methylphenyl)(hydroxy)methylene)-1-(4-methoxyphenyl)-4-(p-tolyl) piperidine-3,5-dione derivatives. The antimicrobial activity of some synthesized compounds has been investigated.