Nitro dimethylaniline

As early as 1938, Shorygin and Topchiyev [10] nitrated dimethylaniline with a solution of nitrogen dioxide in chloroform, but they were only able to obtain 4-nitro-dimethylaniline with a small amount of 3-nitiodimethylaniline. No demethylation of the N-dimethylamino group occurred. 

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 ... 

Diacyl peroxide] = [amine] = 1.0 x 10 mol/L,45 C HDMA p-hydroxymethyl-A/,A/-dimethylaniline NDMA p-nitro-A/,A/-dimethylani-line DMAB p-dimethylaminobenzaldehyde. 

It is prepd by the action of methylamine on 4-chloro-l-nitrobenzene (Ref 5) by the action of methyl iodide (Ref 6), or methyl sulfate on 4-nit roaniline (Ref 7) or by the hydrolysis of 4-nitro-N-methylformanilide with hot coned aq HC1 (Ref 8). In a study of the effect of nitric acid concn on the prods of the nitration of N,N-dimethylaniline to form Tetryl, it was isolated in low yield by the action of nitric acid, d 1.046g/cc, plus Na nitrite on N,N-dimethylaniline (Ref 10). A eutectic mixt with N-ethyl-4-nitroaniline has been patented as a stabilizer for NC (Ref 12). Studies at NPF indicate that 4-nitro-N-methyl-aniline is superior to Centralite, 2-nitrodiphenyl-amine, or Acardite in stabilizing. NC Refs 1) Beil 12, 586, (295) 1125 ... 

Robertson et al.261 measured rates of bromination of some aromatic hydrocarbons in acetic acid containing sodium acetate (to eliminate protonation of the aromatic by liberated hydrogen bromide) and lithium bromide (to reduce the rate to a measurable velocity ) at 25 °C, the second-order rate coefficients for 3-nitro-N,N-dimethylaniline and anisole being 14.2 and 0.016 respectively the former compound was thus stated to be about 1012 times as reactive as benzene (though no measurement of the latter rate coefficient, inferred to be 1.33 xlO-11, could be found in the literature) and this large rate spread gives one further indication of the unreactive nature of the electrophile. Other rates relative to benzene were ... 

Phthalic anhydride condenses with the aniline derivative in the presence of zinc or aluminum chlorides to yield the intermediate benzoyl-benzoic acid, which subsequently reacts with l,3-bis-V,V-dimethylaniline in acetic anhydride to yield the phthalide. The above compound gives a violet-gray image when applied to a clay developer. Clearly this synthesis is also very flexible and variations in shades of color formers have been obtained by varying the aniline components and also by using phthalic anhydrides substituted, for example, by nitro groups or chlorine atoms. Such products have excellent properties as color formers and have been used commercially. Furthermore, this synthetic route is of great importance for the preparation of heterocyclic substituted phthalides, as will be seen later. 

Finally, it should be emphasized that the fluorescence characteristics of aromatic hydrocarbons containing more than one substituent are difficult to predict. These effects cannot be simply extrapolated from those of individual substituents. For instance, in spite of the presence of a nitro group, o- and m-nitroaniline and 3-nitro-N,N-dimethylaniline exhibit fluorescence. 

The formation of /7-nitro-AW-dimethylaniline (in addition to the expected p-nitrophenyl ether) in the reaction of nitrophenate ion with the alkoxyphosphonium salts (158) indicates the intermediacy of the relatively stable interconverting phos-phoranes (159). Loss of dimethylamide ion gives the salt (160), which subsequently undergoes SurAr reactions.142... 

Being involved in a charge-transfer complex with A/,A-dimethylaniline, d5 -a,p-dinitrostilbene undergoes a conversion into its trans form with no changes in the nitro group (Todres et al. 1986 Scheme 2.11). 

On treatment of certain other tertiary aromatic amines with nitrous acid, it has been found that either C-nitroso compounds, nuclear nitro compounds, or jV-nitrosoamines are formed with loss of an alkyl group. In the case of the nitrodimethylanilines, the latter two types of reaction may occur. The formation of nitro-jV-nitrosomethylanilines predominate at room temperature, whereas the formation of polynitro compounds predominates at more elevated temperatures. The formation of nitrosoamines from iVW-dimethylanilines appears to be particularly favored when both ortho positions are occupied by nitro groups, although /V-nitroso compounds were also obtainable from other nitrodimethylanilines. The product of the reaction, of course, is an /V-nitroso secondary amine. 

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... 

Semenczuk and T. Urbanski also showed that dimethylaniline may be nitrated to tetryl by a mixture of nitric acid with acetic acid or acetic anhydride. As yet the only other results mentioned in the literature with reference to this method are those of Orton [11]. He asserted that dimethylaniline gives no N-nitro derivative when reacted with a mixture of nitric acid with acetic anhydride or acetic acid he obtained only 2,4-dinitromethylaniline. 

A nitro group at the meta position is readily hydrolysed in water to the phenolic group with the formation of the nitro derivative of N-methyl-m-aminophenol (VIII). Since technical dimethylaniline usually contains a certain amount of methylaniline,... 

Later Romburgh and Schepers [16] explained that the substance (VII) is also formed from dimethylaniline if nitration is carried out in the presence of a large excess of sulphuric acid (20-fold with respect to dimethylaniline). It is evident that the presence of this substance is undesirable owing to the poor stability of the nitro group in the meta position and to the formation of metal salts of the substance (VIII) which are sensitive to impact. 

The same reaction undoubtedly occurs when dimethylaniline is nitrated. Mertens [6] isolated all three substances from the reaction of nitric acid with dimethylaniline and the substances (X) and (XI) by the treatment of methylaniline with nitric acid. Van Romburgh [7, 20] elucidated the structure of these compounds, in particular the position of nitro groups. 

N)2csH2Br.N(NO).CH3 mw 305.06, K 17.14% lt-yel ndls(from ale), mp 124° was prepd by treating 4-bromodimethylaniline with mixed HN03 H2S04 below 40° or 2-nitro-4-bromo-dimethylaniline with 52% HN03 betw 10-35°... 

The nitration of aniline in the presence of a large amount of strong sulfuric acid results wholly in the formation of m-nitro-aniline, but the similar nitration of dimethylaniline gives principally a mixture of the ortho- and para-derivatives. Mono-methylaniline stands between aniline and dimethylaniline in respect to the orienting effect of its amino group it yields a considerable amount of the m-nitro- compound—and dimethylaniline is preferred for the preparation of tetryl. Commercial dimethylaniline contains a certain amount of monomethylaniline, from which it is extremely difficult to free it, and this in the manufacture of tetryl is converted in part into 2,3,4,6-tetranitro-phenylmethylnitramine, or m-nitrotetryl, pale yellow, almost white, crystals from benzene, m.p. 146-147.087... 

No m-nitrotetryl is produced if pure dimethylaniline is used in the usual process for the manufacture of tetryl. The amount of this impurity in the usual process depends upon the amount of monomethylaniline which may be present. A large excess of sulfuric acid tends toward the production of m-nitro compounds, but a reduction in the amount of sulfuric acid is not feasible for this increases the amount of benzene-insoluble material. m-Nitro-tetryl reacts with water, as TNA does the nitro group in the 3-position is replaced by hydroxyl, and m-hydroxytetryl or 2,4,6-trinitro-3-methylnitraminophenol, yellow crystals from water, m.p. 183°, is formed. This substance resembles picric acid and forms explosive salts. It is readily soluble in water, and... 

These substances were prepared by Mertens89 in 1886 by the action of nitric acid on dimethylaniline (I, II, and III) and on monomethylaniline (II and III). Van Romburgh90 in the same year proved them to be derivatives of benzidine, and at a much later time91 summarized the work which had been done upon them and synthesized the substances in such manner as to prove the position of the nitro groups. 

With deuterium-labeled dimethylaniline as the excited electron donor, primary electron transfer to aryl halides is followed by proton transfer yielding reduced aryl nitro compounds and functionalized dimethylanilines (193). 

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