Preparation and C-formylation of some bis-anilines

Abstract

A number of NN′-dialkyl-NN′-diphenylpolymethylenediamines have been prepared, by the condensation of N-alkylanilines with polymethylene bromides, and formylated by the Vilsmeier reaction to give bis-aldehydes which were characterised as styrene derivatives. The yield of the polymethylenediamine varied considerably with the length of the methylene bridge, being considerably less for tetra- and penta-methylene, owing to preferential cyclisation and disproportionation to give, for example, N-phenylpiperidine and diethylaniline from N-ethylaniline and pentamethylene bromide.