Mild synthesis of N′-aryl-N,N-dimethylformamidinium chloride by Vilsmeier–Haack reagent

Formamidine derivatives could be used as the building blocks for substituted heterocyclic compounds with various biological activities. N′-Aryl-N,N-dimethylformamidinium chlorides have been synthesized in high yields by reaction of aromatic primary amines with Vilsmeier–Haack reagent at room temperature. The structures of all the new compounds were identified by ESI-MS, IR and NMR spectra. The steric structures of some of these compounds were clarified by X-ray single crystal analysis.