SURFACTANT CONTROL OF THE ORTHO-PARA-RATIO IN THE BROMINATION OF ANILINES .2.

We report the bromination of some N,N-disubstituted anilines (N-ethyl- N-methylaniline, N,N-diethylaniline, N-butyl-N-methylaniline, 1-phenyl pyrrolidine, 1-phenylpiperidine) both in aqueous suspension of cetyltr imethylammonium tribromide (CTAB3) and in homogeneous solution (CHCl3) . In the presence of surfactant we observed a regioselectivity differe nt from that observed in homogeneous conditions. The regioselectivity seems to depend on the nature of the substituents on the nitrogen of t he aniline as well as on the temperature. An explanation based on spec ific interactions between the aniline and the packed structure of the aggregate is proposed.