C13 magnetic resonance spectra were obtained for solutions of acetic and benzoic acids and their ethyl esters in 97% sulfuric acid and in fuming (101%) sulfuric acid before and after a 5-hr. heating period at 50C. Comparison of the shifts obtained for the carbonyl group in these solvents with those obtained when phenol, acetone, and acetophenone are dissolved in sulfuric acid leads to the conclusion that the R-COH(+)-OH ion is formed when the carboxylic acids are placed in 97% or fuming sulfuric acid or when their ethyl esters are heated in fuming sulfuric acid for 5 hr. at 50C, and that the R-COH(+)-OC2H5 species are formed when the esters are placed in 97% sulfuric acid at room temperature. (Author).

Project 7903. AD626009. Authors in reverse order on cover. Cover title: Carbon 13 magnetic responance study of the protonation of acetic and benzoic acids and their ethyl esters in concentrated sulfuric acid. "Reprinted from the Journal of Physical Chemistry, 69, 1030 (1965)."