SYNTHESIS OF SOME NEW 1,2,4-TRIAZOLO[3,4-b]-THIADIAZOLE DERIVATIVES AS POSSIBLE ANTICANCER AGENTS

Abstract

3-Substituted-4-amino-5-mercapto-1,2,4-triazoles are versatile synthons for constructing various biologically active heterocycles. Their cyclization with carboxylic acids gives fused five-membered derivatives, whereas with α-bromoketones gives a six-membered heterocycle. In this article we report the synthesis of a series of 1,2,4-triazolo[3,4-b]thiadiazoles 5 starting from 4-amino-3-substituted-5-mercapto-1,2,4-triazoles 3 and fluorobenzoic acids 4 using phosphorous oxychloride as cyclizing agent. Fourteen of the newly synthesized compounds were screened for anticancer properties. Four among them showed in vitro anticancer activity.

Keywords:

• Anticancer activity
• phosphorus oxychloride
• triazolothiadiazoles

The authors are thankful to RSIC, Punjab University, Chandigarh, and RSIC, IIT, Chennai for providing elemental analysis/NMR/mass spectra of the compounds reported herein. KSB is thankful to CSIR, New Delhi for the award of Junior Research Fellowship. We are also thankful to P. M. Akberali of Strides Laboratories, Mangalore for a gift sample of 2,4-dichloro-5-fluoroacetophenone.