THE SYNTHESIS FROM 2,5-DICHLORO-1,1,1,6,6,6-HEXAFLUORO-3,4-DIAZAHEXA-2,4-DIENE OF 4H-3,5-BIS(TRIFLUOROMETHYL)-1,2,4-TRIAZOLE AND SOME 1-SUBSTITUTED AND 4-SUBSTITUTED DERIVATIVES

Treatment of the title azine (3) with an excess of ammonia or ethyl glycinate affords the corresponding diaminoazines (4a) and (4b), which undergo thermal cyclisation to give ammonium 3,5-bis(trifluoromethyl)1-2,4-triazolate (6a) [from which the parent 4H-1,2,4-triazole (1a) can be liberated by aqueous acid treatment] and 4-carboethoxymethyl-3,5-bis(trifluoromethyl)-1,2,4-triazole (1e), respectively in high yield. Reaction of the 4H-1,2,4-triazole (1a) with ethyl propynoate and of its sodium salt (6b) with ethyl bromoethanoate and pentafluoropyridine yield the acrylate (7a)-, carboethoxymethyl (7b)- and fluoropyridyl (9-11)- derivatives of 1H-3,5-bis(trifluoromethyl)-1,2,4-triazole with competing attack on the pentafluoropyridine ring taking place at the 2- and 4- positions. © 1990.