Esterification of carboxylic acids with alcohols is considered as AAC2 type reaction. The specific rate of esterification of acetic acid with methanol, in mixtures of acetonitrile-methanol showed a quadratic dependence on the alcohol concentration. This second order dependence suggests a general base catalyzed mechanism analogous to the [H2O]2 kinetic dependence observed in the acidcatalyzed hydrolysis of carboxylic esters, in highly aqueous media.