Reactivity trends of the base hydrolysis of coumarin and thiocoumarin in binary aqueous-methanol mixtures at different temperatures.

Rate constants for base hydrolysis of both coumarin and thiocoumarin have been studied in different binary aqueous-methanol mixtures at temperature range from 288 to 313 K. The activation parameters of the reactions were evaluated. Moreover, the change in the activation barrier of the investigated compounds from water to water-methanol mixtures were estimated from the kinetic data.