Synthesis and characterization of some new aromatic diamine monomers from oxidative coupling of anilines and substituted aniline with 4-amino-N,N-dimethyl aniline

New aromatic diamine monomers prepared from condensation reactions of aniline, p-chloroaniline, p-nitro aniline, p-chloro-m-nitro aniline with 4-amino-N,N-dimethylaniline (2:1) (aniline:reagent) in the presence of potassium dichromate in acidic media yielded new monomers of a highly colored violet and reddish-violet. Mechanism of the reaction of aniline with 4-amino-N,N-dimethylaniline in the presence of potassium dichromate as an oxidant is expected to proceed through nucleophilic substitution reaction, and the mechanism proceeds facilitated a nucleophilic attack of the substituted aniline ring on the –NH₂ group of the reagent; through partial protonation of their –NH₂ group, forming in diamine dye and their identification was confirmed by IR, ¹H NMR, and CHN analyses.