Unexpected stoichiometry in the cleavage of bis(4-nitrophenyl) phosphate and 4-nitrophenyl phosphorochloridate by alkaline hydrogen peroxide

Reaction of alkaline hydrogen peroxide with bis(4-nitrophenyl) phosphate ion proceeds with simultaneous liberation of ca 2 equiv. of 4-nitrophenol per mole of substrate, and no evidence for build-up of an intermediate. Reaction of HO2- with the more activated 4-nitrophenyl phosphorochloridate gives 4-nitrophenol in up to 40% yield with simple first-order kinetics and no indication of a long-lived intermediate. A fast intramolecular nucleophilic displacement of 4-nitrophenolate ion by peroxide in the initially formed I-nitrophenyl peroxophosphate is proposed to explain this behavior. Copyright (C) 2000 John Wiley & Sons, Ltd.