Nitrobenzene dinitrobenzene

As stated above under TNMe, in Ger during WWII, the prepn of TeNMe by this process was scaled up for use as an intermediate and as a substitute for nitric acid in the V-2 rocket (Ref 26). A pilot plant was built at Newark, NJ for prodn using this procedure. It was destroyed by an expln in 1953 and not rebuilt (Refs 33 44). Other prepns of lesser importance are by the action of Ag nitrite on iodotrinitro-methane (Ref 3) by the action of 90% nitric acid and 25% oleum on malononitrile, yield 45% (Ref 40) by the action of mixed acid on a number of aromatic nitrocompounds, of which nitrobenzene, dinitrobenzene, and nitronaphtha-lene gave the best yields (Ref 13a) and by the action of nitryl chloride on salts of TNMe. 

Mixtures of sodium (or its alloy with potassium) and nitromethane, trichloroni-tromethane, nitrobenzene, dinitrobenzene, dinitronaphthalene, ethyl nitrite, ethyl nitrate or glyceryl nitrate are shock-sensitive, the sensitivity increasing with the number of nitro groups. 

Titanium ions can also he used as redox catalysts for the indirect cathodic reduction of nitro compounds (417). The electroreduction is carried out in an H20-H2S04/Ti(S04)2-(Pb/Cu) system at 45 80°C under 5 20Am . Nitrobenzene, dinitrobenzene, nitrotoluene, 2,4-dinitrotoluene, 2-nitro-m-xylene, nitro-phenol, 2,4-dinitrophenol, nitrophenetole, o-nitroanisole, 4-nitrochlorotoluene, ni-trobenzenesulfonic acid, and 4,4 -dinitro-stilbene-2,2 -disulfonic acid can all be reduced by this procedure to the corresponding amino compounds (418) in good yields (Scheme 146) [513-516]. Tin... 

These optimistic views received a first blow by the discovery of another category of nucleophilic aromatic photosubstitutions occurring in liquid ammonia as a solvent and nucleophile. In this medium the nitroanisoles still show the pattern that had become familiar, i.e., photosubstitution of OCH3 by NH2 with preference for reaction at the position meta with respect to the nitro-group. However, nitrobenzene, dinitrobenzenes, and nitrohalogenobenzenes... 

Figure 9.19 shows the Hammett s equation for degradation rates of substituted nitrobenzenes from experimental data. Photocatalytic degradation of the nitro aromatic compounds by UV/Ti02 from the experimental data reported by Dillert et al. (1995) are used to construct the model. The degradation of nitrobenzenes can be described according to the number of nitro substituents nitrobenzene > dinitrobenzene > 1,3,5-trinitrobenzene (Dillert et al., 1995). 

A few more papers should be mentioned as regards electronic spectra of aromatic nitro compounds nitrobenzene, dinitrobenzene and trinitrobenzene [20] and the work of Barth [21 ] who subjected mono-, di- and tri-nitrobenzenes and toluenes to detailed spectrophotometric ultraviolet-visible studies and developed a quantitative analysis of TNT in the presence of cyclonite, octogene and waxes. 

Benzene (including nitrobenzene, dinitrobenzene, hydroxybenzene, and aminobenzene derivatives)... 

BZ was al so partially oxidized by Ag(II) in a small H-cell with stationary platinum electrodes. Compounds identified in anolyte extracts included phenol, hydroquinone, benzoquinone, benzaldehyde, benzoic acid, methyl benzoate, benzonitrile, benzonitrile aldehyde, and 4-nitro butylnitrile. The yellow color of the anolyte was probably due to benzoquinone, which had a relatively high concentration. A compound which was tentatively identified as benzoquinone epoxide ( 11403) was present at the highest concentration and is believed to be a product of the oxidation of benzoquinone. Numerous nitrated aromatics were also detected and include nitrobenzene, dinitrobenzene isomers, nitrophenol isomers, and dinitnophenol isomers. Intermediates are summarized in Table 3 and classified as I. BZ substrate II. nitrated BZs HI. phenols, quinones, and epoxides IV. nitrated phenols V. BZ substituted with aliphatic and aromatic... 

Nitrobenzene, dinitrobenzene, nitrophenol, and dinitrophenol have been identified as reaction products in HNO3. The nitration of aromatic compounds has been studied extensively [34-45]. Kargin et al. have studied the anodic nitration of aromatic compounds in acetonitrile and sulfolane on a Pt electrode [34]. They attribute the formation of nitrated BZ to a reaction involving either nitronium ion, N02, or anode-generated H2N03, as shown in Equations 32 and 33, respectively. 

Carbonyl complexes of rhodium, ruthenium, osmium, iridium, and platinum, in the presence of H2O and a weak base (e.g., trimethylamine), act as catalysts for the conversion of propene to a mixture of butanol and methylpropanal with the exception of the platinum system, these catalysts are considerably more active than Fe(CO)s as reported by Reppe. Under the same conditions, but in the absence of olefin, the carbonyls act as catalysts for the conversion of CO and H2O to CO2 and H2. The metal carbonyls, together with Fe(CO)s, in the presence of H2O, CO, and a weak base such as McsN, serve as catalysts for the conversion of nitrobenzene, dinitrobenzene, and 2,4- and 2,6-di-nitrotoluene to the corresponding aminobenzene derivatives. 

A significant number of chlorinated haloethers, chlorinated hydrocarbons, and chlorinated benzenes are SVOCs. Examples include bis(2-chloroisopropylether), 4-chlorophenylphenylether, hexachloroelhane, isomers of dichlorobenzene, isomers of trichlorobenze, isomers of tetrachlorobenzene, pentachlorobenzene, and hexachlorobenzene, to name only a few. A number of nitroaromatic SVOCs are considered enviromnentally significant. Remedial action at an old military installation might reqnire the determination of isomers of nitrobenzene, dinitrobenzene, dinitrotoluene, and trinitrotoluene (TNT) in soil and water samples, because they are indicative of explosives. 

Physical Properties. Nitrobenzene, C HjNOj pale yellow liquid, insoluble in and heavier than water, characteristic odour of bitter almonds, (similar to that of benzaldehyde and benzonitrile). /> Nitro toluene, C,H4(CH3)N02, usually pale yellow solid, insoluble in water, m-Dinitrobenzene, C8H4(N02)g, colourless solid when pure, but often pale yellow insoluble in water. 

Nitrobenzene. Nitrobenzene, of analytical reagent quality, is satisfactory for most purposes. The technical product may contain dinitrobenzene and other impurities, whilst the recovered solvent may be contaminated with aniline. Most of the impurities may be removed by steam distillation after the addition of dilute sulphuric acid the nitrobenzene in the distillate is separated, dried with calcium chloride and distilled. The pure substance has b.p. 210°/760 mm. and m.p. 5 -7°. 

Nitrations are usually carried out at comparatively low temperatures at higher temperatures there may be loss of material because of the oxidising action of the nitric acid. For substances which do not nitrate readily with a mixture of concentrated nitric and sulphuric acids ( mixed acid ), the intensity of the reaction may be increased inler alia by the use of fuming sulphuric acid (containing up to 60 per cent, of sulphur trioxide) or by fuming nitric acid. Thus nitrobenzene is converted by a mixture of fuming nitric acid and concentrated sulphuric acid into about 90 per cent, of wi-dinitrobenzene and small amounts of the o- and p-isomers the latter are eliminated in the process of recrystallisation ... 

A brief account of aromatic substitution may be usefully given here as it will assist the student in predicting the orientation of disubstituted benzene derivatives produced in the different substitution reactions. For the nitration of nitrobenzene the substance must be heated with a mixture of fuming nitric acid and concentrated sulphuric acid the product is largely ni-dinitrobenzene (about 90 per cent.), accompanied by a little o-dinitrobenzene (about 5 per cent.) which is eliminated in the recrystallisation process. On the other hand phenol can be easily nitrated with dilute nitric acid to yield a mixture of ortho and para nitrophenols. It may be said, therefore, that orientation is meta with the... 

Nitro compounds. Nitromethane Nitrobenzene ni-Dinitrobenzene. Amides and imides. Acetamide re-Caproamide Acetanilide Benz-anilide Phthalimide. 

Catalytic hydtogenation is the most efficient method for the large scale manufacture of many aromatic and ahphatic amines. Some of the commercially important amines produced by catalytic hydrogenation include aniline (from nitrobenzene), 1,6-hexanediamine (from adiponitrile), isophoronediamine (from 3-nitro-l,5,5-trimethylcyclohexanecarbonitrile), phenylenediamine (from dinitrobenzene), toluenediamine (from dinitrotoluene), toluidine (from nitrotoluene), and xyhdine (from nitroxylene). As these examples suggest, aromatic amines ate usually made by hydrogenating the... 

In azole chemistry the total effect of the several heteroatoms in one ring approximates the superposition of their separate effects. It is found that pyrazole, imidazole and isoxazole undergo nitration and sulfonation about as readily as nitrobenzene thiazole and isothiazole react less readily ica. equal to m-dinitrobenzene), and oxadiazoles, thiadiazoles, triazoles, etc. with great difficulty. In each case, halogenation is easier than the corresponding nitration or sulfonation. Strong electron-donor substituents help the reaction. 

The acids are mixed in a flask (500 c.c.), and the nitrobenzene added in portions of 5—10 c.c. at a time. Heat is evolved, and the mass becomes somewhat deeper in colour. When the nitrobenzene has been added, the flask is heated for a shoit time on the water-bath. K few drops are then potiied into a test-tube of water. The dinitrobenzene should, if the reaction is complete, separate out as a hard pale yellow cake If it is semi-sohd, the heating" must be continued. The contents of the flask are then poured, whilst warm, into a large quantity of water. The dinitrobenzene, which separates out, is filteied at the punap and well washed with water. It is then dried. The yield is nearly theoretical. A few grams should be recrystallised from spirit. The remainder may be used for the next preparation without further puiification. 

Aromatic nitrocompounds (see Fig. 21) such as nitrobenzene and the dinitrobenzenes diminish the rate of polymerization of styrene without suppressing it altogether and without introducing an induction periodi.e., they are typical retarders. Larger quantities are required to produce significant reductions in the rate, and the retardation persists throughout the polymerization, suggests... 

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