REDUCTION OF NITRO- AND NITROSO-COMPOUNDS BY TERVALENT PHOSPHORUS REAGENTS .3. KINETIC STUDY OF TRIETHYL PHOSPHITE REDUCTION OF 2-NITROSOBIPHENYL TO CARBAZOLE

The triethyl phosphite reduction of 2-nitrosobiphenyl to carbazole in triethyl phosphate as solvent is of the first order in both reactants; the activation energy is 11.56 kcal, mole-1, and the entropy of activation ΔS*, at 25° is -29 e.u. The similarity of these data to those obtained for the Menshutkin and Arbusov reactions indicates that the rate-determining step involves the formation of an intermediate complex involving both reagents, possibly (EtO)3P+-O--NAr, which then decomposes rapidly to give products. The possible intermediacy of a nitrene is neither proved or disproved.