Ethyl acetoacetate (I) was stirred with hydrazine hydrate in ethanol to get 5-methyl-2,4-dihydro-3H-pyrazol-3-one (II). This was refluxed with different aryl aldehydes in glacial acetic acid in presence of fused sodium acetate to get corresponding (4E)-4-(substituted benzylidene)-5-methyl-2,4-dihydro-3H-pyrazol- 3-one (IIIa-f). These were treated with 2,4-dinitro phenyl hydrazine to get a series of 4-(substituted phenyl)-5-(2,4-dinitrophenyl)-3-methyl-1,3a,4,5- tetrahydro-pyrazolo-[3,4-c]pyrazole (IVa-f). The structures of the compounds have been established based on their analytical and spectral data. All the compounds have been screened for their analgesic, antibacterial and antifungal activity. Compound IVc, IVe and IVf exhibited significant analgesic activity. Compound IVa was found to be more active against Streptococcus mutans. Compound IVf was found to be more active against both fungal strains. © 2021 Elsevier B.V., All rights reserved.