Nucleophilic Vinylic Substitution. I. The Synthesis and Reactions of 2-Substituted 3,3-Dichloroacry1onitriles

Five 2-substituted 3,3-dichloroacrylonitriles (1 = 2-hydro, 2 = 2-chloro, 3 = 2-methyl, 4 = 2-cyano, and 5 = 2-phenyl) have been prepared and their reactions with methoxide and thiophenoxide studied. Spectral data and chemical reactivity indicate that 1-4 are coplanar molecules, whereas the phenyl group in 5 cannot lie in the same plane as the acrylonitrile system and does not activate the β-chlorine atoms. Nitrile 4 reacted exothermi-cally with methanol to yield 3,3-dimethoxy-2-cyanoacrylimidyl chloride which hydrolyzed readily to the corresponding acrylamide. Nitriles 1, 2, 3, and 5 required the methoxide or thiophenoxide ion to substitute the vinylic chlorine atoms. Dichloromethylenetriphenylphosphorane, prepared from carbon tetrachloride and tri-phenylphosphorine, reacted with benzoyl cyanide to afford a 73% yield of nitrile 5.