The reactions of dimethylformamide with cyanogenchloride and with thionyl chloride have been studied, and several of the products identified by spectroscopic methods. As in the case of a previously reported reaction between dimethylformamide and cyanuricchloride, Vilsmeier adducts are formed. For the cyanogenchloridereaction a mechanism is put forward that accounts for the products more satisfactorily