C nitration

Equipment needed for the above procedures is not always available in the standard laboratory. A useful and widely used method for preparing solutions of dinitrogen pentoxide in nitric acid involves the distillation of mixtures of oleum and potassium nitrate in absolute nitric acid. Another method uses a solution of sulfur trioxide and ammonium nitrate in nitric acid. Although the original report states that solutions of 28 2 % dinitrogen pentoxide in nitric acid can be prepared via this method, a later report suggests that concentrations higher than 30 % are not attainable. 

Dinitrogen pentoxide has also been synthesized from the reaction of ifitric oxide (NO) and dinitrogen trioxide (N2O3) with ozone. The reaction of nitric acid containing a trace of picric acid also yields dinitrogen pentoxide.  

The use of dinitrogen pentoxide in the Ponzio reaction for the oxidation-iutration of oximes to em-dinitro groups has been reported by Russian chemists. Millar and co-workers extensively investigated these reactions and reported the synthesis of 2,4,5,7,9,9-hexanitrofluorene (2), a thermally stable explosive with an oxygen balance better than TNT. Other energetic materials containing gem-dinitro functionality were synthesized from the oximes of acetophenone, 4-nitroacetophenone, a-nitroacetophenone and 2-hydroxyacetophenone. 

The nitration of ethylbenzene (5) to 4-nitroethylbenzene (6) is complete in 5 minutes at 5 °C and further nitration to 2,4-dinitroethylbenzene (7) requires only 10 minutes at 25 2,4- 

Dinitroethylbenzene is a component of the energetic plasticizer known as K-10 (2 1 mixture of 2,4-dinitroethylbenzene and 2,4,6-trinitroethylbenzene). 

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Olah s original preparative nitrations were carried out with mixtures of the aromatic compound and nitronium salt alone or in ether, and later with sulpholan as the solvent. High yields of nitro-compounds were obtained from a wide range of aromatic compounds, and the anhydrous conditions have obvious advantages when functional groups such as cyano, alkoxycarbonyl, or halogenocarbonyl are present. The presence of basic fimctions raises difficulties with pyridine no C-nitration occurs, i-nitropyridinium being formed. ... 

Ccllul-.i. c Nitrate (concentration pr. MtcT than 12,6% nitrogen 9004-70-0 2500 2.4-Dinitroanilinc 97-02-9 5000... 

If the benzotrifluoride contains an ammo group N-nitration in acenc acid and acetic anhydride furnishes the tnfluoromethyl nitroaminobenzene [22] C-nitration... 

C-nitration, in which a nitro group is attached to a carbon atom to form a nitro compd,... 

As already mentioned (Section 1), the,prepn of most of the commonly used high expl compds involves one or more nitration reactions. Indeed, except for ammonium nitrate (AN), primary expls, and BkPdr, it is difficult to bring to mind any expl in common use (or even a laboratory curiosity) that was not prepared by nitration. In Table 1, we list the most important military and commercial high expl compds produced by nitration. We have grouped these compds by nitration type, ie C-nitration, O-nitration, and N-nitration. Note that either nitric acid or mixed acid are the nitrating agents principally employed in industry. This will be discussed further in the next section. The Table also gives Encyclopedia references for those compounds already described in previous Encyclopedia volumes... 

Compound Common Name or Abbreviation C-Nitration Usual. . Nitrating Agent Encyclopedia Reference... 

A somewhat unusual type of C-nitration can occur in reactions between nitric acid and unsaturated hydrocarbons. An example of the nitration of unsaturated hydrocarbons is Quilico s scheme (Ref 31) for the formation of nitroform (CH(N02)3) ... 

C-Nitration does not involve the hydroxyl group but is a reaction with an aliphatic or aromatic hydrocarbon or a substituted derivative to produce such compounds as the nitroparaffins and the nitrotoluenes ... 

Kunz Toth (Ref 22) found that nitration for NS varies linssrly witH tsrnp 2)-Above 14°C nitration is very rapid... 

Sulfate reducers can use a wide range of terminal electron acceptors, and sulfate can be replaced by nitrate as a respiratory substrate. Molybdenum-containing enzymes have been discovered in SRB (also see later discussion) and, in particular, D. desulfuricans, grown in the presence of nitrate, generates a complex enzymatic system containing the following molybdenum enzymes (a) aldehyde oxidoreduc-tase (AOR), which reduces adehydes to carboxylic acids (b) formate dehydrogenase (FDH), which oxidizes formate to CO2 and (c) nitrate reductase (the first isolated from a SRB), which completes the enzy-... 

Olah, G.A. Malhotra, R. und Narang, S.C. Nitration, Methods and Mechanisms, VCH-Verlagsges., Weinheim 1989 Nitro Compounds, Recent Advances in Synthesis and Chemistry, Hrsg. Feuer, H. und Nielsen, A. 77, VCH-Verlagsges., Weinheim 1990 Chemistry of Energetic Materials, Hrsg. Olah, G.A. und Squire, D.R., Academic Press, London 1991... 

Figure 2. Bio geochemical mapping of the Chuvash administration region, Russia. Bio-geochemical regions 1—Pre-Kubnozivilsk, 2—Pre-Sura, 3—Pre-Volga, 4—Biogeochemical provinces—(a) silicon (b) fluorine, and(c) nitrate, Soils 5—Podzoluvisols, 6—Phaerozems, 7—Chernozems, 8—Arenosols.

Figure 9.6. A—temperature electrode B—reference electrode suitable for ISE measurements C—nitrate ISE electrode D—combination electrode E—conductivity electrode.

Vertical distributions of (a) oxygen, (b) dissolved silicon (silicate is the primary chemical species), (c) nitrate, and (d) phosphate at selected latitudes within the Atlantic (20 to 30°W), Indian (91 to 95°W), and Pacific (135 to 158°W) oceans. These are WOCE data obtained from Java Ocean Atlas. 

C. Nitration of S-, Se-, and Te-(Perfluoroalkyl)dibenzothiophenium, -selenophenium, and -tellurophenium Salts (93JA2156)... 

Henry reactions have been extensively exploited for the synthesis of nitrate ester explosives. The condensation of nitroalkanes with aldehydes, followed by esterification of the hydroxy groups with nitric acid, leads to a number of nitrate ester explosives (see Chapter 3). The two examples given above (166 and 167) are synthesized from the C-nitration of the polyols obtained from the condensation of formaldehyde with nitromethane and nitroethane respectively. 

A solution of nitric acid in acetic anhydride is a versatile reagent for nitrolysis reactions and for the A-nitration of amines (see Chapters 5 and 6). This reagent has also found considerable use for the C-nitration of aromatic substrates. ... 

Initial nitration of pyrazole derivatives with nitric acid in acetic or trifluoroacetic anhydrides leads to A-nitropyrazoles, which rearrange to the C-nitrated product on stirring in concentrated sulfuric acid at subambient temperature. This N -> C nitro group rearrangement often occurs in situ when pyrazoles are nitrated with mixed acid. 

C-Nitration of 1,2,3-triazole and 1,2,4-triazole rings can be achieved with either mixed acid or solutions of nitric acid in acetic anhydride. V-Nitration is usually achieved with nitric acid in acetic anhydride at ambient to subambient temperatures. Thermal rearrangement of the N-nitro product to the more stable C-nitro product often occurs at higher nitration temperature. 

This is seen during the nitration of PATO (99), which on treatment with a mixture of nitric acid in acetic anhydride at 40 °C for 30 minutes yields the A-nitro product (106), whereas the same reaction at 60 °C for 1.5 hours yields the C-nitro product (107). An explosive known as PANT (109) has been prepared from the reaction of 4-amino-1,2,3-triazole (108) with picryl chloride followed by C-nitration of the 1,2,3-triazole ring with mixed acid at room temperature. ... 

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