Synthesis of N-α-chlorobenzylidene-N′-(2,4- and 4,2-halogenoiodophenyl)hydrazines and their reaction with thioacetate ion

Abstract

Problems of displacement of iodine from aromatic nuclei are avoided in syntheses of the title compounds from o- and p-halogenoanilines. Treatment of the title compounds with potassium thioacetate gives, according to circumstances, one or more of the following: (i) the 4-acetyl-7-halogeno(iodo)-2-phenyl-4H-1,3,4-benzothiadiazine, by a process involving displacement of ortho-halogen (except when this is chlorine); (ii) the bis-[α-(2,4- or 4,2-halogenoiodophenylhydrazono)benzyl] sulphide; (iii) the N-acetyl-N-(2,4- or 4,2-halogenoiodophenyl)-N′-thiobenzoylhydrazine.