Synthesis, structure, and features of anilinium anilinomethanesulfonates.

Two series of anilinomethanesulfonate derivatives, the anilinium and p-toluidinium anilinomethanesulfonates, were synthesized. They present interesting spectroscopic features and can be used as characteristic derivatives of the parent compounds. These series allow the easy study of the N--H stretching frequencies of the secondary amine whereas difficulties are encountered with the parent compounds due to the occurrence of O--H stretching bands in the same frequency range. All three compounds present a common fragmentation pattern in mass spectral analysis. Through these analyses, the salt structure of the anilinium anilinomethanesulfonates is demonstrated in opposition to a sulfonamide structure, giving further support to the salt structure of other series previously reported.

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.