Hydrocarbon derivatives nitros

Alkali metal reduction is a widely employed method for the preparation of radicals derived from various classes of conjugated compounds such as hydrocarbons, heterocycles, nitro compounds, quinones, and nitriles. For... 

K. -W. Naujack, U. Mohr, and H. Ernst, Contribution of Polycyclic Aromatic Hydrocarbons and Nitro-Derivatives to the Carcinogenic Impact of Diesel Engine Exhaust Condensate Evaluated by Implantation into the Lungs of Rats, Cancer Lett., 37, 173-180 0 987). 

Nielsen, T., Isolation of Polycyclic Aromatic Hydrocarbons and Nitro-Derivatives in Complex Mixtures by Liquid Chromatography, Anal. Chem, 55, 286-290 (1983). 

Essences and extracts of 9 plants as well as safrole, coumarin and hydroxycoumarin, thujone and pinocamphone are explicitly prohibited (Art. 1320). Also forbidden is the use of salicyl aldehyde, hydrocarbons, pyridine derivatives, nitro compounds and organic nitrites (Art. 1321). 

Grimmer, G., Brune, H., Deutsch-Wenzel, R., Dettbarn, G., Jacob, J., Naujack, K. W., Mohr, U., and Ernst, H. (1987). Contribution of polycyclic aromatic hydrocarbons and nitro-derivatives to the carcinogenic impact of diesel engine exhaust condensate evaluated by implantation into the lungs of rats. Cancer Lett yj, 173-180. 

There are four subfamilies of hydrocarbons, known as alkanes, alkenes, alkynes, and aromatics. (These families will be discussed in detail in Chapters 4 and 5.) The alkane and aromatic families of hydrocarbons occur naturally the alkenes and alkynes are manmade. Both types of hydrocarbons are used to make other families of chemicals, known as hydrocarbon derivatives. Radicals of the hydrocarbon families are made by removing at least one hydrogen from the hydrocarbon and replacing it with a nonmetal other than carbon or hydrogen. Ten of these hydrocarbon derivatives will be discussed in detail in the appropriate chapters associated with then-major hazards alkyl halides, nitros, amines, ethers, peroxides, alcohols, ketones,... 

Trinitrophenol, also known as picric acid, is composed of yellow crystals and is a nitro hydrocarbon derivative. It is shipped with not less than 10% water as a wetted explosive. There is a severe explosion risk when shocked or heated to 572°F, and it reacts with metals or metallic salts. In addition to being flammable and explosive, it is toxic by skin absorption. Picric acid has caused disposal problems in school and other chemistry laboratories where the moisture has evaporated from the container as the material ages. When the picric acid dries out, it becomes a high explosive closely related to TNT. Picric acid has been found in various amounts in school labs across the country. In a dry condition, picric acid is dangerous and should be handled by the bomb squad. The structure and molecular formula for picric acid are shown in Figure 6.3. 

Ammonium picrate is a nitro hydrocarbon derivative. It is composed of yellow crystals with not less than 10% water by mass. Ammonium picrate is highly explosive when dry and a flammable solid when wet, and is slightly soluble in water. The four-digit UN identification number for ammonium picrate with not less than 10% water is 1310. The primary uses are in pyrotechnics and explosives. The structure and molecular formula are shown in Figure 6.4. 

TLV of 1 ppm in air. The four-digit UN identification number is 1652. The NFPA 704 designation is health 3, flammability 2, and reactivity 1. Nitrobenzene is a nitro hydrocarbon derivative, but it is not very explosive. The primary uses are as a solvent, an ingredient of metal polishes and shoe polishes, and in the manufacture of aniline. The structure and molecular formula are shown Figure 8.29. 

Nitro-PAHs are polycyclic aromatic hydrocarbon derivatives that contain one or more nitro groups covalently bound at chemically reactive positions on the aromatic ring. Mixtures of nitrated PAHs are generated either by reactions of PAHs with nitrogen oxides or as byproducts of the incomplete combustion of fossil fuels (65). A wide variety of nitro-PAHs have been isolated from environmental sources, such as coal fly ash, diesel emission particulates, cigarette smoke and carbon black photocopier toners (29, 52, 63, 74, 75, 86, 87, 88). Structures of representative nitro-PAHs isolated from the environment are shown in Figure 1. 

Xitro- derivatli- e of aliphatic hydrocarbon. react readily with formalde hyde in the presence of alkaline catalysts. showing a striking difference in this respect from other compoimds commoni classified as hydrocarbon derivatives. This reaeii dtA is not manifested by nitro-aromatic.<3, which behaA e in much the. same manner as the unsubstituted hydrocarbons. 

In general, nitro-hydrocarbons are most readily identified by reduction to the corresponding amine (above), which is then identified as its benzoyl or other derivative (p. 374). (M.ps., pp. 550-551.)... 

Nitroamlines. Acetyl derivatives (p. 388), Benzoyl derivatives (p. 388). Diamines. Diacet> l derivatives (p. 388), Dibenzoyl derivatives (p. 388). Halogeno-hydrocarbons, a-Naphthyl ethers (from reactive halogen compounds, p. 391, and their Picratcs, p. 394), Nitro-derivatives (p.39i). Carboxylic acid (if oxidisable side chain) (p. 393). 

The nitroparaffins are named as derivatives of the corresponding hydrocarbons by usiag the prefix "nitro" to designate the NO2 group (1), eg, 1,1-dinitroethane, CH2CH(N02)2- The salts obtained from nitroparaffins and the so-called nitronic acids are identical and may be named as derivatives of either, eg, sodium salt of i7ti-nitromethane, or sodium methanenitronate [25854-38-0]. 

In mononitration the hazard is due to the extremely violent reaction of the unreacted hydrocarbon with the MA, and to the fact that nitro derivatives of cresols are formed in the process, along with nitro toluenes. The last stage — trinitration — is dangerous due to the drastic conditions of the reaction which requires coned acids and a high temp. The earlier method of trinitration at which temps up to 120° were applied was particularly hazardous. If the mono-nitre toluene hns not b n freed from nitro-cresols, trinitration is still more dangerous, due to the high reactivity of nitrocresols, and their liability to undergo oxidation... 

A series of nitrated and unsaturated hydrocarbons. The base molecule for nomenclature purposes is usually called the "ethylene series1 because the first member is ethylene, C2H4 hence a molecular type CnH(2n-x)Nx02x s derived. Other compds in the series are named after corresponding paraffins by adding to the stem ene or ylene such as 1-nitro propylene, C3H5NO2. Olefms with two conjugeted double bonds are called dienes , such as butadiene. 

Solvents can be classified into three categories according to their polarity namely, polar protic, dipolar aprotic and non-polar. Most of the common solvents fall under one of following chemical classes Aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, phenols, ethers, aldehydes, ketones, carboxylic acids, esters, halogen-substituted hydrocarbons, amines, nitriles, nitro-derivatives, amides and sulfur-containing solvents (Marcus, 1998). In certain cases a mixture of two or more solvents would perform better than a single solvent. 

The same reaction can be applied, not only to the aromatic parent substances, the hydrocarbons, but also to all their derivatives, such as phenols, amines, aldehydes, acids, and so on. The nitration does not, however, always proceed with the same ease, and therefore the most favourable experimental conditions must be determined for each substance. If a substance is very easily nitrated it may be done with nitric acid sufficiently diluted with water, or else the substance to be nitrated is dissolved in a resistant solvent and is then treated with nitric acid. Glacial acetic acid is frequently used as the solvent. Substances which are less easily nitrated are dissolved in concentrated or fuming nitric acid. If the nitration proceeds with difficulty the elimination of water is facilitated by the addition of concentrated sulphuric acid to ordinary or fuming nitric acid. When nitration is carried out in sulphuric acid solution, potassium or sodium nitrate is sometimes used instead of nitric acid. The methods of nitration described may be still further modified in two ways 1, the temperature or, 2, the amount of nitric acid used, may be varied. Thus nitration can be carried out at the temperature of a freezing mixture, at that of ice, at that of cold water, at a gentle heat, or, finally, at the boiling point. Moreover, we can either employ an excess of nitric acid or the theoretical amount. Small scale preliminary experiments will indicate which of these numerous modifications may be expected to yield the best results. Since nitro-compounds are usually insoluble or sparingly soluble in water they can be precipitated from the nitration mixture by dilution with water. 

The chemical character of a compound is not fundamentally altered by the introduction of a nitro-group. Thus the ring-substituted nitro-derivatives of the hydrocarbons are neutral compounds like the hydrocarbons themselves. If, however, a nitro-group enters a substance having, for instance, an acid character, then this character is thereby intensified the nitrophenols, for example, are more acidic than phenol. Correspondingly, the strength of bases is decreased by nitration the nitranilines are less basic than aniline. 

---