Microwave-assisted synthesis of novel 1,3,4-thiadiazolyl-substituted 1,2,4-triazines as potential antitubercular agents

A series of triazines have been synthesized starting from 5-alkyl-1,3,4-thiadiazole-2-thioles (1a-d). On reaction with ethyl bromoacetate in the presence of anhydrous K2CO3 under microwave irradiation (MWI), these yielded corresponding esters (2a-d) which on hydrazinolysis under MWI produced (5-alkyl-1,3,4-thiadiazol-2-yl sulfanyl) acetohydrazides (3a-d). The reaction of 3a-d with omega-bromoacetophenone under MWI yielded 6-aryl-3-[(5-alkyl-1,3,4-thiadiazo1-2-yl sulfanyl)methyl]-1,2,4-triazines (4a-h). All the synthesized triazines showed bl vitro antitubercular activity, (C) 1998 Academic Press.