Reaction of sodium hydroxymethanesulfonate with substituted anilines

The reactions of substituted anilines with sodium hydroxymethanesulfonate to form the anilinomethanesulfonates were studied in 50% ethanol--water at 0--50 degrees. The Arrhenius rate constants were 5.4 X 10(10) exp(--16,400/RT) M-1 min-1 for aniline, 4.8 X 10(11) exp(--17,100RT) M-1 min-1 for p-anisidine, 7.1 X 10(9) exp(--14,500/RT) M-1 min-1 for p-toluidine, 1.5 X 10(13) exp(--21,100/RT) M-1 min-1 for p-chloroaniline, and 1.1 X 10(12) exp(--19,800/RT) M-l min-1 for p-bromoaniline. Some equilibrium constants and hydrolysis rate constants of the products also were calculated. Hydrolysis rate constants were temperature independent. These reactions had a p value of --3.40 in the Hammett equation. The solvent concentrations used proved to be very convenient for obtaining high yields of the aminomethanesulfonates.