4(H)-1,2,4-triazole derivatives with expected biological activity. Part IV. Synthesis of substituted 3,4,5-triaryl-1,2,4-triazoles.

A series of 23 3,4,5-triaryl-1,2,4-triazoles with various substituents in one, two, or all three aromatic rings were prepared for screening tests as potential antibacterial, mostly antituberculotic agents. The synthesis, depending on the nature and position of the substituents, was accomplished by one of the following methods; (A) condensation of symmetrically substituted bis(alpha-chlorobenzylidene)hydrazine with an aniline derivative; (B) reaction of an aniline derivative with a symmetrical diaroylhydrazine in the presence of PCL3; (C) direct condensation of aroylhydrazine with an appropriately substituted N-phenylbenzimidoyl chloride. The latter method was considered to be most advantageous; it warranted highest yield and purity of the products and made it possible to prepare triazoles with three different aryl groups.