Synthesis of imidazole, coumarin and isoxazole containing new triheterocyclic compounds and their derivatives

Abstract

Reaction of substituted 4-amino-3-methyl-5-styrylisoxazoles <b style="">1</b> with 3-(2-bromoacetyl)coumarin <b style="">2</b> in abs. ethanol leads to the formation of 3-[2-(3-methyl-5-styryl-4-ylamino)acetyl]chromen-2-ones <b style="">3</b>, which are subsequently cyclised by treatment with KSCN to 3-[1-(3-methyl-5-styryl-isoxazol-4-yl)-2-mercapto-1<i style="">H</i>-imidazol-4-yl]-1-benzopyran-2<i style="">H</i>-ones <b style="">4</b>. 2-Mercaptoimidazoles <b style="">4</b> on treatment with ClCH₂COCl in DMF / abs. ethanol give unexpected product esters <b style="">5</b>. The reaction of <b style="">4</b> with phenacyl bromides results in the formation of thioethers <b style="">6</b>.