Microwave assisted synthesis of novel pyrazolone derivatives attached to a pyrimidine moiety and evaluation of their anti-inflammatory, analgesic and antipyretic activities

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)-1 H-pyrazol-5(4 H)-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 C 6 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.