In the present research work, the motto was to develop new chemical entities as potential anti-inflammatory, analgesic and antipyretic agents. Various 4-(2-amino-6-(substituted)pyrimidin-4-yl)-3-methyl-1-(substituted)-1H-pyrazol-5(4H)-one derivatives (5a-5j) and their Schiff bases (6a-6j) were synthesized. The newly synthesized compounds were characterized by TLC and spectral data. The compounds containing pyrazolone and amino pyrimidine as basic moieties (5a-5j), were screened for their anti-inflammatory, analgesic and antipyretic activities, compounds 5a, 5c-5f, 5h exhibited activities nearly similar to the standard. The pharmacological studies reveal that the presence of 4-hydroxy, 4-methoxy, 4-(N,N-dimethylamino) or 2-hydroxy groups on phenyl ring at C6 of amino pyrimidine exhibits anti-inflammatory, analgesic and antipyretic activities nearly similar to the standard and substitutions like 4-chloro, 2-nitro, 3-nitro or 4-nitro on same phenyl ring lead to a decrease in activities.

Several 1-(substituted)-3-methyl-1H-pyrazol-5(4H)-one as RA1-RA9 were synthesized and compounds were screened for antitumor activity against Ehrlich ascites carcinoma (EAC) cells and antimicrobial activity. Elemental analysis, mass spectral data, 1H-NMR, and IR confirmed the structure of the newly synthesized compounds. Some of the tested compounds showed good antitumor and antimicrobial activity. Compounds RA1, RA4, and RA9 exhibit highest antitumor activity against EAC cells in comparison with 5-flurouracil as standard drug.Keywords: Ehrlich ascites carcinoma; Pyrazolone; Antitumor; N-substitution; Antimicrobial.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7027 J. Sci. Res. 4 (1), 183-192 (2012)