Chemistry of polyhalogenodiazabutadienes. Part V. Routes to new triazolyl systems: substituted 3-amino-4,5-diaryltriazoles

Abstract

Reaction of the 4-aryl-1,1,4-trichloro-2,3-diazabutadienes (III; X = Cl) with aniline formed the new 3-anilino-5-aryl-4-phenyl-1,2,4-triazoles (VIII). Treatment of the 1-aryl-1,4-dichloro-4-morpholinodiazabutadienes (X) with aniline gave both the 3-morpholino-(XII) and 3-anilino-triazoles (VIII), the latter being formed by amine displacement. The mechanism of formation of the anilinotriazole (VIII) from the trichloride (III; X = Cl) involved initial replacement of one of the geminal chlorine atoms in (III) followed by replacement of the second to form N-(NN′-diphenylamidino)-(p-substituted)benzohydrazonyl chlorides (VII; X = Cl), which then cyclised to form the triazoles (VIII) in high yields. The hydrazonyl bromides (VIII; X = Br) have been prepared and cyclised in triethylamine to give the anilinotriazoles (VIII), in almost quantitative yields.