Microwave assisted synthesis of novel pyrimidine derivatives and investigation of their analgesic and ulcerogenic activity

A novel series of 6-bromo-3-(2-morpholino methyl amino)-6-substituted phenyl pyrimidine-4-yl-2H-chromone-2-one (6aM–6jM) and 3-(2-((piperidine-1-yl)methyl amino)-6- substituted phenylpyrimidin-4-yl)-6-bromo-2H-chromone-2-one (6aP–6jP) have been synthesized from 3-(2-amino-6-pyrimidin-4-yl)-6-bromo-2H-chromen-2-one (5a–5j) which were synthesized from 3-acetyl-6-bromo-2H-chromen-2-one (3). The reactions were carried out by conventional and microwave method. The salient feature of microwave method are rapid reaction rate, cleaner reaction condition, and enhancement in chemical yield compared to conventional method, the structures of the synthesized compounds were characterized by I.R., 1H NMR, 13C NMR, Mass spectroscopic techniques. All the compounds screened at a dose of 20 mg/kg body weight by in vivo analgesic activity. Among all the synthesized compounds, compound 6aP, 6aM, 6cM, 6iM, and 6jM showed significant analgesic activity and compounds 6cM and 6iM showed highly significant activity against the standard drug Diclofenac sodium using acetic acid-induced writhing model. Among all the synthesized compounds which show potent analgesic activity such as 6aP, 6aM, 6cM, 6iM, and 6jM were further evaluated for acute- ulcerogenic activity. Among all compound 6cM and 6iM was found to be most promising analgesic agent devoid of ulcerogenic effects.