New novel derivatives of 3-((benzo[d]oxazol-2-ylmethyl)amino)-1-(2,5-difluorobenzoyl)-4-(2-(4-(substituted)phenyl)hydrazono)-1H-pyrazol-5(4H)-one (5a-g) were prepared by refluxing a mixture of ethyl 2-(4-(2-(4-subtituted methyl)phenyl)hydrazono)-1-(2,5-difluoro benzoyl)-4,5-dihydro-5-oxo-1H-pyrazol-3-yl)amino Carboxylic acid. (4a-g) and 2- amino phenol, polyphosphoric acd, dichloro methane and cyclo hexane. The synthone 4a-g were synthesized by refluxing a mixture of 2 a-g and tetra hydro furan. The newly synthesized compounds were characterized by IR, 1H-NMR, 13C-NMR, mass spectra and elemental analysis. The newly synthesized compounds were screened for their Biological activity.