Kinetics of the Reaction of 2,4-Dinitrochlorobenzene with 4-Aminothianes and Measurements of the Base Strengths of the 4-Aminothianes

Article abstract of DOI:10.1021/jo00335a012

The kinetics of the reaction of 2,4-dinitrochlorobenzene with substituted 4-aminothianes have been investigated at 50 deg C in 80percent dioxane.Amines with an axial C(4)-NH2 bond react at a slightly faster rate than the corresponding epimers.The kinetic data are interpreted in terms of solvation of the lone pair of electrons on the nitrogen atom and steric hindrance to solvation of the ammonium ion.The N-2,4-dinitrophenyl derivatives of the amines were also prepared.The pK_a values of the substituted 4-aminothianes were determined at 27 deg C in 80percent Methyl Cellosolve.Aryl-substituted aminothianes were less basic than the unsubstitute d 4-aminothianes apparently due to the polar effect of the aryl group which could be transmitted along the ? bond.