Synthesis, characterization and antimicrobial activity of novel sulphapiperazine containing arylazopyrazoles

Mannich reaction of benzotriazole, ethyl-4-amino benzoate and formaldehyde in ethanol afforded 4-(1H)-benzotriazoyl methyl amino benzoate, which on treatment with hydrazine hydrate results in the 4-(1H)-benzotriazoylmethyl amino benzoyl hydrazide.This compound on condensation with pre-prepared various ethyl-2-substituted phenyl hydrazono-3-oxobutyrates (6a–h), furnished 1-(4-((1H-benzo[d][1,2,3]triazol-1-yl) methyl amino) benzoyl)-3-methyl-4-(2-(4-(4- alkylpiperazin-1-ylsulfonyl) phenyl) hydrazono)-1H-pyrazol-5(4H)-ones (7a–h). All these compounds (7a–h) were characterized by spectral studies. The compounds showed significant antimicrobial activity against various bacteria and fungi.