38899-22-8

Upstream product

• 95-64-7 4-amino-o-xylene 
• 99-51-4 4-nitro-o-xylene 
• 95-47-6 o-xylene 
• 17988-43-1 (3,4-dimethylphenyl)-trimethylsilane 
• 43192-07-0 N-3,4-dimethylphenyl-hydroxylamine 

Downstream Products

• 1799434-68-6 2-bromo-3,4-dimethylaniline 
• 22364-29-0 2-bromo-4,5-dimethylaniline 
• 1111733-58-4 N-(3,4-dimethylphenyl)-2-oxo-2-phenyl-N-(4-(trifluoromethyl)phenethyl)acetamide 

Relevant academic research and scientific papers

Synthesis of Nitrosobenzene Derivatives via Nitrosodesilylation Reaction

The electrophilic ipso-substitution of trimethylsilyl-substituted benzene derivatives into nitrosobenzene derivatives is reported. The optimization of the reaction conditions was performed for moderately electron-deficient, electron-rich, and sterically hindered starting materials by varying reaction time, temperature, and equivalents of NOBF4. Also, a stable intermediate of the nitrosation reaction could be characterized by 19F NMR which can be assigned to a NO+ adduct with the nitrosobenzene derivative. This complex decomposes upon aqueous workup and liberates the desired nitrosobenzene derivative.

Synthesis of 1H-Indazoles from Imidates and Nitrosobenzenes via Synergistic Rhodium/Copper Catalysis

Nitrosobenzenes have been used as a convenient aminating reagent for the efficient synthesis of 1H-indazoles via rhodium and copper catalyzed C-H activation and C-N/N-N coupling. The reaction occurred under redox-neutral conditions with high efficiency and functional group tolerance. Moreover, a rhodacyclic imidate complex has been identified as a key intermediate.

Kinetics and mechanism of nitrosation of toluene, o-xylene, and m-xylene in trifluoroacetic acid, or in acetic-sulfuric acid mixtures, under nitric oxide

The title reactions give good yields with m-xylene, and modest yields with toluene and o-xylene which are successfully directly nitrosated for the first time. The advantages of purging with nitric oxide are demonstrated and discussed. The kinetics have been successfully interpreted in terms of a mechanism in which both the aromatic substrate and the nitrosoaromatics form, reversibly, complexes with nitrosonium ion. The nitrosoaromatics are unstable under the acid conditions and the method is successful only because of the protective complexation with the nitrosonium ion.

Structural investigations of C-nitrosobenzenes. Part 2. NMR studies of monomer-dimer equilibria including restricted nitroso group rotation in monomers

Energy barriers associated with rotation of nitroso groups in monomeric nitrosobenzene and eleven monomeric substituted nitrosobenzenes in solution have been measured by total 1H NMR bandshape analysis. ΔG? (298.15 K) values for the rotations are in the range 31-41 kJ mol-1. The values for 4-substituted compounds correlate well with the Hammett σp+ parameter for the substituent. The experimental energy barrier for nitrosobenzene is compared with theoretical calculations. Monomerdimer equilibria of these compounds in solution have been investigated, with ΔH, ΔSominus; and ΔGominus; data calculated for the dissociation of both Z- and E- azodioxy dimers to monomers. Kinetic data, based on time-dependent and two-dimensional exchange spectroscopy (2D-EXSY) NMR measurements, have been obtained for the dissociation of 3-methylnitrosobenzene and 3,5-dimethylnitrosobenzene dimers. Energy profiles for the ground and transition states of both dimers and monomers (including exchange between both their rotameric forms) are discussed.

Structural investigations of C-nitrosobenzenes. Part 1. Solution state 1H NMR studies

Ambient and low temperature 1H NMR spectra of a wide range of 3- and 4-monosubstituted, and some di- and tri-substituted C-nitrosobenzenes have enabled -N=O substituent constants for the static and rotating ring molecules to be calculated. This has provided information on the shielding anisotropy of the N=O group which in turn leads to the firm identification of the monomeric and dimeric solution species. In all cases lowering the solution temperature enhances the relative populations of dimers to monomers, with the (Z)-azodioxy dimer being preferred over the (E)-form, irrespective of the nature of the solid state dimeric structure.

Direct Nitrosation of Aromatic Hydrocarbons and Ethers with the Electrophilic Nitrosonium Cation

Various polymethylbenzenes and anisoles are selectively nitrosated with the electrophilic nitrosonium salt NO(1+)BF4(1-) in good conversions and yields under mild conditions in which the conventional procedure (based on nitrile neutralization with strong acid) is ineffective.The reactivity patterns in acetonitrile deduced from the various time/conversions in Tables 2 and 3 indicate that aromatic nitrosation is distinctly different from those previously established for electrophilic aromatic nitration.The contrasting behavior of NO(1+) in aromatic nitrosation is ascribed to a rate-limiting deprotonation of the reversibly formed Wheland intermediate, which in the case of aromatic nitration with NO2(1+) occurs with no deuterium kinetic isotope effect.Aromatic nitroso derivatives (unlike the nitro counterpart) are excellent electron donors that are subject to a reversible one-electron oxidation at positive potentials significantly less than that of the parent polymethylbenzene or anisole.As a result, the series of nitrosobenzenes are also much better Broensted bases than the corresponding nitro derivatives, and this marked distinction, therefore, accounts for the large differentiation in the deprotonation rates of their respective conjugate acids (i.e.Wheland intermediates).

The Stoichiometric and Catalytic Oxidation of Various Substrates with a Novel Macrocyclic Binuclear Copper(I) Dioxygen Complex as an Intermediate

The stoichiometric oxidations of hydroquinones, phenols, 3,5-di-tert-butylcatechol and 3,4-dimethylaniline with a macrocyclic Cu(I) dioxygen complex and with a Cu(II) complex show that in some cases the substrate is oxidized both by the Cu(I) dioxygen complex and by the corresponding Cu(II) complex, while in other cases the Cu(II) complex shows no activity; the combination of the Cu(I) dioxygen complex and the Cu(II) complex as oxidants results in catalytic oxidation of the substrate, but no catalysis is observed when only the Cu(I) dioxygen complex is active.

Electrophilic intermediate in the reaction of glutathione and nitrosoarenes

A kinetic study is reported of the reaction of glutathione (γ-L-glutamyl-L-cysteinylglycine, GSH) with nine substituted nitrosobenzenes (3,4-Me2 4-Me, 3,5-Me2, 3-Me, parent, 3-MeO, 4-Cl, 3-Cl, 3-NO2). Previous workers have shown that this reaction proceeds in parallel pathways, producing the appropriate N-arylhydroxylamine and GSSG or a sulfinanilide adduct ArNHS(O)G; a rapid equilibrium addition to form a common intermediate, a semimercaptal ArN(OH)SG, has also been observed. In the present study, equilibrium constants for the formation of this intermediate from ArNO and GSH have been measured by a kinetic method, and the kinetic behavior of the slower additional reactions of the semimercaptal have been examined in detail. For experiments carried out at constant pH and buffer concentration, the decay of ArN(OH)SG follows the rate law k2GSH[GSH] + k2(rearr). A comparison with product ratios previously reported shows that the bimolecular term with GSH represents the process forming ArNHOH and GSSG, while the unimolecular term represents the rearrangement to the sulfmanilide. The former process is found to be proportional to [OH-] for solutions near neutrality, is not buffer catalyzed, and has a ρ value of +1.4. This suggests a mechanism in which glutathione anion GS- reacts at the sulfur of the adduct displacing ArN-(OH) as a leaving group. The rearrangement reaction follows σ+ with a ρ+ value of -3.5 and has a rate law containing a pH-independent term and terms for catalysis by H+ and the acid component of the buffer. An 18O tracer study shows that the S=O oxygen in the sulfmanilide is derived from solvent, not the original N=O group. A mechanism is proposed with rate-limiting N-O cleavage, either uncatalyzed involving direct heterolysis with OH- as a leaving group or catalyzed by acids with H2O as the leaving group. The species produced is a cationic intermediate ArN+SG, a nitrenium ion stabilized by both the aryl ring and the directly attached sulfur atom. Aryl-stabilized nitrenium ions are commonly encountered in Bamberger-like rearrangements of hydroxylamine derivatives. The sulfur atom of PhN(OH)SG is shown to provide an approximately 106 rate acceleration for N-O cleavage in a comparison with the Bamberger rearrangement of PhNHOH.