Unsaturated compounds containing nitrogen. Part 4. Further reactions of 1-chloro-2,3-diazabutadienes with S-nucleophiles

Abstract

1-Chloro-1,4-diaryl-2,3-diazabutadienes (Ar¹CClNNCHAr²), prepared by the reaction of thionyl chloride with aroylhydrazones (Ar¹CONHNCHAr²), react with thiosemicarbazide or thiocarbohydrazide to give 2-arylidenehydrazino-5-aryl-1,3,4-thiadiazoles, and with potassium thiocyanate to give 1-thiocyanato-1,4-diaryl-2,3-diaza-butadienes which isomerize thermally to arylideneamino-5-aryl-1,3,4-thiadiazoles. 1-Chloro-1,4-diphenyl-2,3-diazabutadiene reacts with potassium ethylxanthate to give a 1-ethylxanthyl-2,3-diazabutadiene which on pyrolysis yields 2,5-diphenyl-1,3,4-thiadiazole.