Nitro derivatives of aminophenols

This explosive (m. p. 285°C) was first obtained by Komer and Contardi [43] in 1909, using the reaction  

The compound may also be prepared by other methods for example, van Duin and van Lennep [26] obtained it by reacting ammonia with trinitroanisidine. They also investigated its explosive properties. 

The compound is known to be stable when heated at 95°C for 30 days it remains unchanged. However, on boiling with a dilute sodium hydroxide solution it decomposes to trinitroresorcinol and ammonia. It is less sensitive to impact than tetryl, but more sensitive than picric acid. The initiation temperature is 335°C. 

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Also present but not essential in permanent hair colorants are nitro dyes which dye hair without oxidation. These dyes, nitro derivatives of aminophenols and benzenediamines, impart yellow, orange, or red tones. Although they have good tinctorial value, they are not as colorfast as the oxidative dyes. They also are used in semipermanent hair colorants. 

Manufacture of 1.3.6.8 tctranitrocarbazol Preparation of 1.2.6.S tetranitrocarbazol Amide derivatives of trinitroanilincs Hexanitrodiphenylurca Hexanitrooxanilide Nitro derivatives of aminophenols Trinitro-m-phenylenediamine Picramte add... 

Manufacture of l.3.6,S-tetranitrocarba2ol Preparation of 1,2.6.8-leiranitrocarbazol Amide derivatives of trinitroanilincs Hexanilrodiphcnylurca Hexanilrooxanilide Nitro derivatives of aminophenols Triniiro-m-phcnylenediamine Picramic acid... 

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,... 

Glowiak [20] examined the properties of the diazotization products of numerous nitro derivatives of o-aminophenol, viz. ... 

Nitro-4-methoxyaniline has been prepared by heating nitro-hydroquinone dimethyl ether with aqueous ammonia 2 by heating the tetramethylammonium salt of 3-nitro-4-aminophenol 3 by the hydrolysis of 2-nitro-4-methoxyacetanilide la with alcoholic potassium hydroxide 11 lc or hydrochloric acid ld and by the hydrolysis of the />-toluenesul fonamide,4 the 3-nitrobenzenesul-fonamide,5 the 3-nitro-/>-toIuenesulfonamide,3 and the acetyl derivative of the />-toluenesulfonamide6 of 2-nitro-4-methoxyani-line with concentrated sulfuric acid. 

Unfortunately, length restrictions did not permit us to consider in detail the tremendous amount of information available on heteroleptic complexes, which are briefly reviewed in Chapter 7. The reviews do not consider a broad group of autocomplexes — derivatives of nitro-, aminophenols, ketoenols, and also chloro-, bromo-, and iodophenols that are stable to hydrolysis and are only formal analogs of alkoxides and phenoxides. 

Sodium hydrosulfite can be used as the white crystalline product of commerce, or it can be prepared in the. course of the reaction by adding zinc dust to a solution of sodium bisulfite. The latter procedure has been employed for the reduction of indigo and for the preparation of o-aminophenol from the corresponding nitro derivative. The reaction involved is as follows ... 

Nitro dyes This group of sani-permanent dyes are aromatic amines (to be exact, derivatives of p-phenylendiamine and o-phenylendiamine), aminophenols and aminophenyl ethers, which contain nitro gronps. Some examples are shown in Figure 4.3.1. 

Reaction of 1,3,5-trinitrobenzene (TNB) with o-aminophenols in the presence of potassium carbonate in dipolar aprotic solvents has been shown to produce 1,3-dinitrophenoxazines (5). This reaction is thought to involve nitro group displacement to yield intermediates (4), which undergo oxidative substitution of hydrogen by the amino group.18 The corresponding reaction of TNB with o-aminothiophenols yields 1,3-dinitrophenothiazine derivatives. 

Mono- or diacyl derivatives that undergo cyclization to benzoxazoles on heating or under the influence of dehydrating agents are formed as intermediates in this reaction [134, 452, 453, 459, 461 173], Phosphorus oxychloride [453, 457], boric anhydride [455, 461, 462], or polyphosphoric acid [134, 471] are used as condensing agents. In particular, 2-hydroxy-5-nitrobenzoxazole, used for the synthesis of antivirus medicines, has been obtained by the reaction of condensation of 4-nitro-2-aminophenol with (NH2)2CO in pyridine [474],... 

Heating of 7-nitro-l,2,4-benzoxadiazine-3-carboxylic acid or basic hydrolysis of its ethyl ester results in 2-amino-6-nitrobenzoxazole [495, 496]. Earlier this compound was wrongly ascribed the structure of 7-nitro-l,2,4-benzoxadiazine [497], Nitrated 2-aminobenzoxazoles are obtained in good yield in the reaction of o/t/zo-aminophenols with cyanogen bromide [498-500] or with S-methylisothiourea derivatives (Scheme 2.77) [501],... 

The metabolism of nitrobenzenes to quinone-imines arises from a six-electron reduction of the nitro group to the corresponding aniline metabolite via the intermediate nitroso and hydroxylamine analogs. Aromatic ring hydroxylation by CYP ortho or para to the aniline nitrogen then generates the aminophenol derivative. The conversion of a nitrobenzene derivative to a quinone-imine is illustrated with the catechol-O-methyltransferase inhibitor tolcapone, an... 

In order to circumvent the problem of the use of selenium, analogous systems based on the use of sulphur compounds have been developed [85-88]. Aromatic nitro compounds can be reduced by CO in water/methanol media at 120-150 °C and 1-1.5 bar pressure [85, 86]. From nitrobenzene, aniline was obtained with selectivity over 97 % at 100 % PhN02 conversion. The reaction proceeds in the presence of a multicomponent catalyst consisting of a base (preferably a strong base such as sodium hydroxide or methoxide) and sulphur compounds. The ratio of catalytic effectiveness of sulphur compounds is as follows S CS2 H2S COS = 1 1.3 10 10. Vanadium(V) compounds can be added to improve selectivity in aniline formation. Aromatic dinitro derivatives undergo this reaction and selectivity to one of the two main products (phenylenediamine and nitroaniline) can be switched by the choice of reaction conditions. The main byproduct of the reaction of nitrobenzene is PhNHCOOMe [85, 86]. It has been shown that, under the catalytic conditions, methyl phenylcarbamate can be hydrolysed to afford aniline. More forcing conditions (up to 300 bar CO) have also been employed in order to increase the activity [87]. The same catalytic system has been used to reduce nitrophenols to the corresponding aminophenols [88]. 

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