Aromatic nitro-derivatives

The first step of the reaction involves nitration of the aromatic skeleton of the substance to be detected. Then the aromatic nitro derivatives so produced are reduced with sodium dithionite, in acid medium, to the corresponding amines these are then diazotized and coupled with N-(l-naphthyl)-ethylenediamine to yield an azo dye (cf. Fig. 21). 

Aromatic nitro derivatives may act as electron acceptor molecules affording complexes with electron donor partners. This is the case of 1,3-dinitrobenzene which forms a 1 1 donor-acceptor complex with tetrathiafulvalene221. These complexes are of interest in the field of electrical conductivity. 

TABLE 13. Apparent stability constants of molecular complexes between 2-hydroxypyridine and some aromatic nitro derivatives in hen/enevA at 25 °C125. Reproduced by permission of societa chimica Italiana from Reference 125... 

The protecting group is considered to be more stable to acid hydrolysis than the phenylethylenedioxy acetal and to possess stability comparable to that of other aromatic nitro derivatives under reducing conditions. 

Sodium salts of aromatic nitro-derivatives, n.o.s. explosive 0203... 

The action of fuming nitric acid transforms benzene and its homologues (toluene, xylene) into nitro-compounds (nitrobenzene, etc.), which remain in the acid liquid, from which the mineral oil is subsequently separated. The liquid is then diluted with as much water and the solution neutralised with caustic soda solution and extracted with ether. The ethereal liquid (dried with a few granules of caldum chloride and filtered) is evaporated at a gentle heat and the residue weighed. If tar oils are present, this residue will consist of a reddish-brown oily liquid, heavier than water and with the odour characteristic of aromatic nitro-derivatives. The weight found, divided by 1-15 (mean sp. gr. of aromatic nitro-compounds), will give the volume. 

If the tar oils are accompanied by small quantities of mineral oils, the latter may dissolve in the aromatic nitro-derivatives and so settle to the bottom of the vessel. In such case the deposited layer is separated and distilled in a small flask, only the first portions of the distillate, containing the bulk of the light mineral oils, being collected. This is treated with zinc and hydrochloric acid (cooling somewhat) to reduce the nitro-com-pounds, and diluted with water the amines formed dissolve in the water as hydrochlorides and the mineral oils separate as slightly coloured light drops. 

Melphalan and the racemic analog have been prepared by two general routes (Scheme I). In Approach (A) the amino acid function is protected, and the nitrogen mustard moiety is prepared by conventional methods from aromatic nitro-derivatives. Thus, the ethyl ester of N-phthaloyl-phenylalanine was nitrated and reduced catalytically to amine I. Compound I was reacted with ethylene oxide to form the corresponding bis(2-hydroxyethyl)amino derivative II, which was then treated with phosphorus oxychloride or thionyl chloride. The blocking groups were removed by acidic hydrolysis. Melphalan was precipitated by addition of sodium acetate and was recrystallized from methanol. No racemization was detected [10,28—30]. The hydrochloride was obtained in pure form from the final hydrolysis mixture by partial neutralization to pH 0.5 [31]. Variants of this approach, used for the preparation of the racemic compound, followed the same route via the a-acylamino-a-p-aminobenzyl malonic ester III [10,28—30,32,33] or the hydantoin IV [12]. 

As shown by Hackel [144] glycerine trinitrate (nitroglycerine) does not form addition compounds with any of the aromatic nitro derivatives (mono-, di- or tri-nitro compounds). This is probably due to the inadequate number of nitro groups in nitroglycerine. 

The polarity of nitric ester. All esters forming addition compounds possess high polarity. On the contrary, the ester of low polarity-penthaerythritol tetranitrate does not give addition compounds with any of the above mentioned aromatic nitro derivatives. 

Aromatic azocompds can be prepd by a)reduction of aromatic nitro derivatives in alkaline soln... 

Primary and secondary aliphatic or aromatic nitro derivatives can also be reduced to amines by NaBH4 in THF in the presence of palladium on charcoal [PBl]. The reduction is compatible with ester and nitrile groups and also with chlorides, but aryl bromides are reduced under these conditions (Figure 5.1). 

PPE/PA and a compatibilizer by aromatic nitro-derivative Bencini and Ghidoni, 1993... 

Nitro compounds are reduced to the corresponding amine. Unlike hydride reductions, both alkyl nitro compounds (2-methyl-2-nitro-1,3-propanediol was reduced to l-amino-2-methyl-1,3-propanediol in 95% yield)566 and aromatic nitro derivatives [nitrobenzene was reduced to aniline with Ti(S04)3 in sulfuric acid and cetyltrimethylammonium bromide] are electrolytically reduced. 7 jf conditions are modified, reductive coupling can give azoxy compounds such as 568 (from 569) or diazo compounds. A variety of acid derivatives are reduced under electrochemical conditions, including nitriles (to amines), acids (to alcohols),5 E572 estejs (jq alcohols), and amides (to alcohols). It is possible to selectively reduce a cyclic imide to a lactam.575... 

The Role of Co-catalysts in the Reductive Carbonylation of Aromatic Nitro Derivatives Catalyzed hy Transition Metal Carbonyl Clusters... 

Co-cataly.sts in the Reductive Carhonylation of Aromatic Nitro Derivatives... 

Nitroalkanes have been rarely used as substrates for catalytic reactions with carbon monoxide. This is mainly due to the fact that they usually react with transition metal complexes in their aci form [1]. Thus their reactivity is seldom comparable to the one shown by aromatic nitro derivatives. The catalytic synthesis of oximes by carbonylation of nitroalkanes is a rare example not only of their use in this type of catalysis, but also of the formation of these derivatives. 

Any attempt to extend the deoxygenation properties of tertiary amines to other aromatic nitro derivatives was unsuccessful. For instance, using PI1NO2 as substrate, we could observe only a very low conversion to aniline (however, see Chapter 3.5. for the system PtCl2(PPh3)2/SnClVNEt3 and its behaviour in the absence of platinum). 

Conversion of acetylenes into substituted maleate esters (62) by addition of two carboxy-groups to the unsaturated system is achieved using palladium and mercury salts in the presence of carbon monoxide. Diphenylacetylene and aromatic nitro-derivatives in the presence of carbon monoxide and... 

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