The reaction of some representative N,N-dialkylanilines with N- hydroxymethylphthalimide in concentrated sulphuric acid solution (the Tscherniac-Einhorn reaction) has been studied and the structures of the resultant phthalimide derivatives elucidated (principally by means of p.m.r. spectroscopy). In some instances, when two equivalents of the reagent were used, the in corporation of two phthalimidomethyl groups into the N,N-dialkylaniline molecule was achieved. Similar results were obtained when the less reactive N-hydroxymethylchloroacetamide was used as the amidomethylating reagent.