Kinetic studies of the reactions of some phenols and alkyl aryl ethers with dinitrogen pentoxide in perfluorocarbon solvents

Abstract

The reaction of dinitrogen pentoxide in perfluorocarbon solvents with phenols and alkyl aryl ethers carrying halogeno ring-substituents results in nitrodehydrogenation. Rate measurements show that the preferred orientation of nitration is ortho > para > meta to the hydroxy group; the kinetic isotope effect, k_H/k_D, has a value close to unity. Phenols show considerably higher reactivity than similarly substituted alkyl phenyl ethers, and a mechanism is suggested involving initial interaction of N₂O₅ with the hydroxy function followed by reaction via cyclic transition states.