Design and Synthesis of Some Enaminonitrile Derivatives of Antipyrine as Potential Novel Anti-Inflammatory and Analgesic Agents

Abstract

The starting (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)carbon-hydrazonoyl dicyanide (2) was used as a key intermediate for the syntheses of novel acyclic enaminonitriles 3-10. The newly synthesized compounds were characterized by elemental analyses and spectral data (IR, 1H NMR, 13C NMR and mass spectra). The anti-inflammatory activity data indicated that many of tested compounds protected rats from carrageenan-induced inflammation, and tested compounds 3, 4, 9 and 10 were the most potent among tested compounds. The analgesic activity was determined by the hot plate test (central analgesic activity) and acetic acid induced writhing assay. The results revealed that compounds 3, 4, 9, and 10 exhibited significant activity. However, compound 10 proved to have better or equivalent activities in comparison to the reference drug.