Phase Transfer Catalyzed Synthesis and Antibacterial Activity of Water-soluble S-Triazolo3,4-b1,3,4thiadiazoles Containing Piperazine Group

摘要

6/3-(4-Chlorophenyl)-s-triazolo[3, 4-b][1, 3, 4]thiadiazoles (2a-e) and (5a-e) were synthesized respectively by intermolecular cyclization of 5-aryl / 4-chlorophenyl-4-amino-3- mercapto-1, 2, 4-triazoles (1a-e) and (4) with 4-chlorobenzoic acid / aryl acids, which were condensed with piperazine under phase transfer catalyst TBAB to yield the corresponding free bases of monopiperazine derivatives and followed to form water-soluble salts (3a-e) and (6a-e) with hydrochloric acid in good yields. The in vitro biological results showed that piperazine group conjugated with the above fused heterocycles played an important role in antibacterial activity. The structures of novel compounds were confirmed by IR, 1H NMR, MS and elemental analysis.