Practical one-pot transformation of electron-rich aromatics into aromatic nitriles with molecular iodine and aq NH3 using Vilsmeier–Haack reaction

Abstract

Various electron-rich aromatics could be efficiently transformed into the corresponding aromatic nitriles in good to moderate yields by treatment with DMF and POCl3, followed by the reaction with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH) in aq NH3. Some of less reactive aromatics, such as anisole, 1,2-dimethoxybenzene, 1,4-dimethoxybenzene, and mesityrene, could be also transformed into the corresponding aromatic nitriles in good to moderate yields using N-methylformanilide and O(POCl2)2, followed by the reaction with molecular iodine in aq NH3. Moreover, propiophenone derivatives could be successfully transformed into the corresponding β-chlorocinnamonitriles by the reaction with DMF and POCl3, followed by the reaction with molecular iodine and aq NH3. These reactions are novel metal-free one-pot methods for the preparation of aromatic nitriles from electron-rich aromatics and β-chlorocinnamonitriles from propiophenones.