Substituent effects leading to ultra-slow proton removal from an intramolecular hydrogen bond
Abstract
Electron-withdrawing substituents (R2 and R3) result in a remarkable reduction in the rate coefficient for removal of the hydrogen-bonded proton from 2-alkyl-4-(R2,R3-phenylazo)resorcinol monoanions by hydroxide ion such that the reaction can be followed by conventional spectrophotometry with t1/2 in the range of minutes.