Acid catalysed hydrolysis of N-substituted 4-chlorobenzamides

Abstract

The hydrolysis of 4-chlorobenzamide, and 4-chloro-N-methyl-, -N-ethyl-, -N-isopropyl-, -N-n-butyl-, and -N-t-butyl-benzamides have been carried out over a wide range of acidities (10–90% w/w) in sulphuric acid at 100·7 °C. Interpretation of the rate data by use of the Bunnett criterion of mechanism has been found unsatisfactory, and by the Bunnett–Olsen criterion only reasonable; however, the data do fit an empirical two-term rate equation. The rate of hydrolysis of 4-chloro-N-t-butylbenzamide shows a sudden reversal of the general trend of decreasing rate with increasing chain length.