The synthesis of novel derivatives of pyrazole-3-carboxylate (3-5) from methyl 4-(benzofuran-2-yl)-2,4-dioxobutanoate (1) is reported. Synthesis of substituted 1,3,4-oxadiazoles (7-11) and 5-amino pyrazole-4-carboxylate (12) derivatives starting from the 5-(benzofuran-2-yl)-1-phenyl-1H-pyrazole-3-carbohydrazide (6) are also described. Twelve new compounds were synthesized and their identities have been established on the basis of elemental and spectroscopic analysis such as IR, H-1 NMR, C-13 NMR, Mass Spectra. The compounds were also screened for their antibacterial and antifungal activities against Gram-positive, Gram-negative bacteria and a fungus.