Synthesis and Antioxidant Activity of Some Novel Nicotinonitrile Derivatives Bearing a Furan Moiety

Abstract

As a part of ongoing studies in developing new potent antioxidant agents, 2‐amino‐4‐(furan‐2‐yl)‐5,6‐dimethylnicotinonitrile 4 was utilized as a key intermediate for the synthesis of some new pyrimidines 5 and 11, form (acet)amide 6, 7, urea and thiourea 9, 10, 1,8‐naphthyridines 12, 13, and 14. Moreover, condensation of 4 with 5,5‐dimethyl‐1,3‐cyclohexanedione and cyclohexanone in ethanol furnished the pyridine derivatives 16 and 17, respectively. Furthermore, refluxing of 4 with ethylenediamine in carbon disulfide afforded the 4,5‐dihydro‐1H‐imidazol‐2‐yl pyridine derivative 19. In addition, refluxing of 4 with carbon disulfide and concentrated sulfuric acid furnished the pyridine derivatives 20 and 21, respectively. The reaction of 4 with phenacyl chloride and ethyl chloroacetate in dimethylformamide in the presence of catalytic amount of triethylamine afforded the pyridine derivatives 22 and 23, respectively. Finally, heating of 4 with 1‐phenyl‐3‐(piperidin‐1‐yl)propan‐1‐one hydrochloride in glacial acetic acid afforded phenylpropylamino pyridine derivative 24. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, 1H‐NMR, and mass spectral data. Representative compounds of the synthesized products were evaluated as antioxidant agents. Compounds 8, 19, and 22 are promising compounds.