Effects of the Nucleophile Structure on the Mechanisms of Reaction of 1-Chloro-2,4-Dinitrobenzene with Aromatic Amines in Aprotic Solvents

NORMA NUDELMAN; SILVANA ALVARO; MÓNICA SAVINI; VIVIANA NICOTRA; JEANETE YANKELEVICH

Collect.Czech. Chem. Commun.

Institute of Organic Chemistry and Biochemistry Academy of Sciences of the Czech Republic

Lugar: Praga.; Año: 1999 vol. 64 p. 1583 - 1593

The kinetics of reactions of 1-chloro-2,4-dinitrobenzene with aniline and several substituted aromatic amines, B, in toluene shows a quadratic dependence of the second-order rate constant, kA, on [B], which is preserved even in the presence of increasing amounts of dimethylaniline, while the reaction with N-methylaniline shows a linear dependence of kA vs [B]. All these results are interpreted by the ?dimer nucleophile? mechanism, and confirmed by the effects of a non-nucleophilic hydrogen bond acceptor tertiary amine which show the relevance of the structure of the nucleophile and the role of mixed aggregates in defining the mechanisms of aromatic nucleophilic substitutions with amines inaprotic solvents.