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 K2CO3under 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 of3a–dwith ω-bromoacetophenone under MWI yielded 6-aryl-3-[(5-alkyl-1,3,4-thiadiazol-2-yl sulfanyl)methyl]-1,2,4-triazines (4a–h). All the synthesized triazines showedin vitroantitubercular activity.