The Behavior of 3-Anilinoenone and N-Phenyl Cinnamamide toward Carbon Nucleophiles: Spectroscopy and X-Ray Studies Reveal Interesting New Synthesis Routes to Nicotinonitriles and Tetrahydropyridine-3- Carbonitrile
The reactions of 3-anilinoenones with active methylene nitrile either in acid or base media were investigated. Reasonable mechanisms to account for the formation of the nicotinonitrile, ethyl nicotinate, nicotinic acid and dienamide derivatives were suggested. A one-pot multicomponent reactions (MCRs) of enaminone, aniline and either malononitrile or ethyl cyanoacetate in acid or base media afforded 1,3,5-triacycl benzene derivative. Treatment of N-phenyl cinnamamide with malononitrile in refluxing sodium ethoxide lead to tetrahydropyridine derivative. The structures of the synthesized compounds were elucidated by elemental analyses, X-ray and a variety of spectroscopic methods, including proton and carbon nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR), correlation spectroscopy (COSY), heteronuclear single quantum coherence spectroscopy (HSQC), and mass spectrometry (MS).