Regioselective Synthesis of 1,2,4‐Triazol‐3(2H)‐ones and Their 3(2H)‐Thiones: Kinetic Studies and Selective Pyrolytic Deprotection.

Abstract

Selective pyrolytic deprotection of 2-ethyl and 2-cyanoethyl-4-arylidenimino-1,2,4-triazol-3(2H)-ones and their 3(2H)-thiones was studied by flash vacuum pyrolysis. This study is useful in regioselective synthesis of 2- and 4-substituted 1,2,4-triazoles of potential biological applications. The kinetic results and product analysis lend support to a reaction pathway involving a six-membered transition state. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:50–55, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10086