Synthesis and biological activity of 4-aryl benzofuro [3,2-d] pyrimidine-3-N-oxides and 3-(3 '-aryl-1 ',2 ',4 '-triazol-4 '-yl)benzofurans

Abstract

A series of 3-amino-2-aroylbenzofurans (1a-d) have been prepared from salicylonitrile and substituted phenacyl bromides by a single step procedure and converted into 2-aroyl-3-thioureidobenzofurans (2a-m) by reacting with various alkyl and aryl isothiocyanates.. Further reaction of compounds 2a-m with hydroxylamine hydrochloride furnished 2-arylamino-4-arylbenzofuro [3,2-d] pyrimidine-3-N-oxides (3a-1). Acylation of 1a-d,to 4a-n and subsequent cyclization with hydrazine hydrate gave a series of 2-alkyl/aryl-3,4-dihydro-3-amino-4-hydroxy-4-arylbenzofuro [3,2-d] pyrimidines, (5a-n), which on treatment with formic acid resulted in the formation of a series of biheterocyclic-3-(3'-alkyl/aryl-1 1,2',4'-triazol-4'-yl)-2-aroyl benzofurans (6a-n). Representative compounds have been screened for antimicrobial and antiinflammatory activity.