Oxidation of dimethylaniline

Reaction of N,N-dimethylaniline with 1-cyanobenziodoxol 1783 to afford N-methyl-N-cyanomethylaniline 1784 in 97% yield has been discussed in Section 12.1 [31]. Analogously, oxidation of dimethylaniline with iodosobenzene and trimethylsilyl azide 19 at 0°C in CDCI3 gives the azido compound 2040 in 95% yield, iodobenzene, and HMDSO 7 [194, 195] (Scheme 12.56). Likewise, the nucleophilic catalyst 4-dimethylaminopyridine (DMAP) is oxidized, in 95% yield, to the azide 2041, which is too sensitive toward hydrolysis to 4-N-methylaminopyri-dine to enable isolation [194, 195]. Amides such as 2042, in combination with tri-... 

It is prepared by air oxidation of dimethylaniline in the presence of phenol and copper salts as well as sodium chloride. The reaction product consists of tetra- to hexamethylated pararosanilines (see 119, p. 541) ... 

Methyl violet is produced by action of other oxidising agents on dimethylaniline, such as iodine and chloranil. According to Brunner and Brandenburg bromine acts on dimethylaniline, forming a brominated methyl violet [21]. On the other hand, the dyestuff is not produced by oxidation of dimethylaniline in acid solution, with lead peroxide, manganese dioxide, or chromic acid. 

An interesting example is the oxidation of dimethylaniline (39). Oxidation of (39) with manganic acetate in acetic acid gives as the sole isolable product 4,4 -bis(dimethylamino)diphenylethane (40). Apparently the first step in the reaction is dealkylation by the mechanism of equation (7.69),... 

Anodic oxidation of dimethylaniline can give different products, depending on the conditions. Thus under conditions where the initial radical cation readily loses a proton, the product arises from oxidation of a... 

The oxidation of N, A-dimethylaniline by aerated, ethanolic cupric chloride to give a mixture of products including methyl and crystal violets is simple second-order when an excess of amine is used Presumably Cu(I) is re-oxidised by dissolved oxygen, for otherwise the observed linearity of log [residual amine] versus time plots would not be found as Cu(II) disappears. Under nitrogen the kinetics are complex, but a new optical absorption (472 and 1007 nm) appears immediately on mixing the reactants. This absorption decays whilst a new one at 740 nm develops. The latter absorption originates from a 1 1 complex formulated... 

One of numerous examples of LOX-catalyzed cooxidation reactions is the oxidation and demethylation of amino derivatives of aromatic compounds. Oxidation of such compounds as 4-aminobiphenyl, a component of tobacco smoke, phenothiazine tranquillizers, and others is supposed to be the origin of their damaging effects including reproductive toxicity. Thus, LOX-catalyzed cooxidation of phenothiazine derivatives with hydrogen peroxide resulted in the formation of cation radicals [40]. Soybean LOX and human term placenta LOX catalyzed the free radical-mediated cooxidation of 4-aminobiphenyl to toxic intermediates [41]. It has been suggested that demethylation of aminopyrine by soybean LOX is mediated by the cation radicals and neutral radicals [42]. Similarly, soybean and human term placenta LOXs catalyzed N-demethylation of phenothiazines [43] and derivatives of A,A-dimethylaniline [44] and the formation of glutathione conjugate from ethacrynic acid and p-aminophenol [45,46],... 

Methylene blue is also produced by the oxidation of dimethyl-p-phenylenediamine without the addition of dimethylaniline, and was discovered in this way by Caro in 1876. In explanation of this modification it is considered that the intermediate product (not isolated) at stage II is probably converted into the substance IV, in which the other ring is quinonoid, by replacement of the NH-group by... 

Triphenylamine (TPA), AWW W -tetramethyl-p-phenylenediamine (TMPD) and dimethylaniline (DMA) have been popular substrates for reaction under pulse radiolysis conditions. One of the earlier reports dealt with the formation of the radical cation of TMPD by reaction (k = 3 x 108 M 1 s 1) with the peroxy radical derived from oxidation of methylene chloride (CHCI2O2) by pulse radiolysis26. DMA is also oxidized to its radical cation by the same reagent (k = 2.5 x 107 M 1s 1). Since then it has been... 

Fig. 4.5. Major routes of metabolism for lidocaine (4.128). Direct hydrolysis yields 2,6-dimethylaniline (2,6-xylidine, 4.129) and 2-(diethylamino)acetic acid (diethylglycine, 4.130). Hydrolysis of the metabolites monoethylglycinexylidine (4.131) and glycinexylidine (4.132) also yields 4.129. The metabolites 4.131 and 4.132 also undergo hydroxylation at the aromatic ring to form 4.133 and 4.134, respectively, which, in turn, are hydrolyzed to 4-hydroxy-2,6-dimethylaniline (4.135). This compound can also be formed by oxidation of 4.129. 

To illustrate such a feature, let us compare the reactions of A, A-dimethylaniline cation-radicals with nucleophiles in their dependence on the manner of the one-electron oxidation of the parent molecule. Works by Kirchgessner et al. (2006), Weinberg and Reddy (1968), and Andreades and Zahnow (1969)... 

Tetryl (8) can be prepared from the nitration-oxidation of A, A-dimethylaniline (90) with a variety of nitrating agents and conditions, including the use of a large excess of 70 % nitric... 

The immonium ion derived from oxidation of N,N-dimethylaniline can be trapped by reaction with methanol to give the relatively stable a-methoxymethyl... 

Baeyer-Villiger reaction of 57 with H3PO5 gives the phenol 59. However, the peracetic acid or trifluoroperacetic acid gives the carboxylic acid 58 (equation 93). Oxidation of V,V-dimethylaniline in aqueous CH3CN at 30 °C affords the V-oxide in 82% yield . 

Oxadiazolinones, substituted, 391 Oxaziranes, oxidation of, 406 2-Oxazolidones, 442 Oximes, 395 oxidation of, 415, 416 reaction with C-nitroso compounds, 351 4,4 -[Oxybis(4-nitro-o-phenyleneazo)]bis-JV,N-(dimethylaniline), 294... 

Nitration of dimethylaniline results in the oxidation of one of the methyl groups to the carboxyl group which is not strongly linked to nitrogen and is readily split off as carbon dioxide. Thus, as the nitration of dimethylaniline proceeds, gases consisting of NO and N02 (from the reduction of nitric acid) and of C02 (from the oxidized N-methyl group) are evolved abundantly. 

On the other hand, Elliott and his co-workers 4 maintain that the evidence for the nitro- structure is unsatisfactory, and that the p-nitro-dimethylaniline produced with dimethylaniline is a secondary product obtained either by oxidation of the nitroso-compound or by direct nitration of the amine. The addition of ethyl hydrogen sulphate to a solution of nitrosulphonic acid in sulphuric acid does not yield nitro -ethane. Elliott suggests that the crystalline acid is essentially the nitroso- form, ON. O. SO 2. OH, but that in the molten condition and in sulphuric acid solution this form is in equilibrium with another of yO ... 

Another anodic coupling reaction was achieved by anodic oxidation of N-methylbenzthiazolone-2-hydrazone (274) in aqueous sulfuric acid containing dimethylaniline. The final product (275) was isolated in 30% yield426 [Eq. (142)]. 

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