26492-31-9Relevant articles and documents
Mechanism of the dimethyldioxirane oxidation of N,N-dimethylanilines
Buxton, P. Christopher,Ennis, Julie N.,Marples, Brian A.,Waddington, Victoria L.,Boehlow, Todd R.
, p. 265 - 268 (1998)
Relative rates of dimethyldioxirane oxidation of a number of para-substituted N,N-dimethylanilines in acetone at 5°C are compared with those of reactions with methyl iodide and other oxidants. The reactions with dimethyldioxirane followed the Hammett relationship with a ρ value of -1.0. Measurement of the second order rate constants for the dimethyldioxirane reactions in aqueous acetonitrile containing potassium nitrate at 21°C, showed better correlation with the Hammett relationship (ρ = 0.89) than with the Okamoto-Brown model (ρ+ = 0.56). The reaction rates are accelerated greatly in the presence of water such that the respective pseudo first order rate constants for the oxidation of N,N-dimethyl-4-nitroaniline in acetone and water are 6.3 × 10-3 and 5.86 s-1, respectively. All of the data are consistent with a concerted electrophilic mechanism and there is no evidence of free radical or electron transfer reactions.
Kinetics and Mechanism of Oxidation of Anilines by Hydrogen Peroxide As Catalyzed by Methylrhenium Trioxide
Zhu, Zuolin,Espenson, James H.
, p. 1326 - 1332 (2007/10/02)
The oxidation of anilines by hydrogen peroxide in methanol is catalyzed by methylrhenium trioxide, CH3ReO3.The major product of the oxidation of aniline at room temperature is nitrosobenzene.For 4-substituted N,N-dimethylanilines, the N-oxide is the only product.The rate constants for the oxidation of 4-substituted N,N-dimethylanilines follow a linear Hammett relationship with ρ = -1.19.The rate constants for the reaction between CH3Re(O)2(O2), referred to as A, and 4-XC6H4-NMe2 are as follows: 4-Me, 24.5; 4-H, 18.4; 4-F, 12.7; 4-Br, 8.7; and 4-NO2, 1.0 L mol-1 s-1.This shows that electron-withdrawing substituents inhibit the reaction.The corresponding rate constant for the oxidation of aniline is 2.04 +/- 0.11 L mol-1 s-1, whereas it is 178 +/- 11 L mol-1 s-1 for the oxidation of N-phenylhydroxylamine to nitrosobenzene.A mechanism has been assigned on the basis of the kinetics and product yields.The data are consistent with the attack of the nucleophilic nitrogen atom on one of the peroxidic oxygen atom of A.The kinetics of the reaction of CH3ReO3 and hydrogen peroxide in methanol were also investigated.The formation of the 1:1 peroxide compound A is characterized by an equilibrium constant K1 = 261 +/- 6 L mol-1.The equilibration occurs rapidly: k1 = 1150 +/- 60 L mol-1 s-1 and k-1 = 4.4 +/- 0.4 s-1 at 25.0 deg C.The bisperoxide compound, CH3Re(O)(O2)2(H2O), B, forms more slowly.The rate constant is k2 = 308 +/- 16 L mol-1 s-1, and the equilibrium constant is K2 = 814 +/- 14 L mol-1 at 25.0 deg C in methanol.B reacts with the anilines, but much more slowly than A.
Studies in Tertiary Amine Oxides. Part V - Carbon-13 Nuclear Magnetic Resonance Spectra of some N-Aryl Tertiary Amines, the Corresponding N-Oxides and the Meisenheimer Rearrangement Products
Khuthier, Abdul-Hussain,Al-Rawi, Jasim M. A.,Al-Kazzaz, Abdul K.,Al-Iraqi, Mohammed A.
, p. 104 - 108 (2007/10/02)
The carbon-13 NMR spectra of some N-(2- or 4-nitrophenyl) tertiary amines and their corresponding N-oxides have been analysed.These N-oxides undergo thermal rearrangement to O-arylhydroxylamines, for which the 13C NMR spectral assignments were also carried out.The N-oxidation effect on the aromatic and aliphatic fragments is calculated.
