Synthesis of 1-(4-phenoxyphenyl)-3-[5-(substituted aryl)-1,3,4-oxadiazol-2-yl]propan-1-ones as safer anti-inflammatory and analgesic agents

A novel series of 1-(4-phenoxyphenyl)-3-(5-(substituted aryl)-1,3,4-oxa- diazol-2-yl)propan-1-one was synthesized by reaction of 3-(4-phenoxyben- zoyl)propionic acid with several aryl acid hydrazides in phosphorus oxychlo- ride. The structures of the compounds were supported by IR, 1 H- and 13 C-NMR, MS data and elemental analysis results. These compounds were tested for their anti-inflammatory, analgesic, ulcerogenic and lipid peroxidation actions. A few compounds were found to have very good anti-inflammatory activity in the car- rageenan-induced rat paw edema test, while a fair number of the compounds showed significant analgesic activity in the acetic acid-induced writhing test. These new compounds showed very low ulcerogenic action with reduced ma- londialdehyde content (MDA), which is one of the by-products of lipid peroxi- dation.