Various ethyl-2-substituted phenyl hydrazono-3-oxobutyrate (2a-h)
condensation with 2-hydroxy benzoic acid hydrazide (3) to afford 1-(2-hydroxybenzoyl)-
3-methyl-4-(2- substituted phenyl hydrazono)-1H-pyrazol-5(4H)-one (4a-h). The
structures of all these compounds (4a-h) were recognized on basis of analytical and
spectral data. The newly synthesized compounds were evaluated for their antimicrobial
activity against various bacteria and fungi.