Alkaline hydrolysis of the methyl esters of benzo[b]furan-2- and 3-, benzo[b]thiophen-2- and 3-, and indole-2- and 3-carboxylic acids
Abstract
The rates of alkaline hydrolysis of carboxylic acid methyl esters, in ‘70% dioxan’ solution, follow the sequence 3-benzo[b]furyl > 2-benzo[b]furyl > 2-benzo[b]thienyl > indol-2-yl > indol-3-yl > phenyl > 3-benzo[b]thienyl. The effect of benzo-substitution on the rates of hydrolysis has been determined for furan, thiophen, and pyrrole esters; it ranges from a rate enhancement of ca. 200 (for pyrrol-2-yl) to a 70% rate reduction (for 3-thienyl).