Nitrocyclohexane, oxidation

The kinetics and mechanisms of the MnO oxidations of nitrocyclohexane and nitrocyclopentane are entirely similar . The combined rate data for solutions at 0.5 M ionic strength are... 

The catalytic oxidation of cyclohexane is performed in the liquid phase with air as reactant and in the presence of a catalyst. The resulting product is a mixture of alcohol and ketone (Table 1, entry 12) [19]. To limit formation of side-products (adipic, glutaric, and succinic acids) conversion is limited to 10-12 %. In a process developed by To ray a gas mixture containing HC1 and nitrosyl chloride is reacted with cyclohexane, with initiation by light, forming the oxime directly (Table 1, entry 12). The corrosiveness of the nitrosyl chloride causes massive problems, however [20]. The nitration of alkanes (Table 1, entry 13) became important in a liquid-phase reaction producing nitrocyclohexane which was further catalytically hydrated forming the oxime. 

TABLE 9.2 The Effect of Temperature on Hydrogenation of Nitrocyclohexane over Silver-Zinc-Chromium Oxide"... 

MCPBA has been regarded as the reagent of choice for the conversion of primary aliphatic amines into the corresponding nitro compounds. The peroxy acid must be used in excess to minimize formation of dimers of the intermediate nitroso compounds, llie yield of nitroalkane is also increased if the reaction is carried out at elevated temperature, since this favors the monomeric rather than the dimeric foim of the intermediate nitrosoalkane and allows it to be oxidized further. For example, cyclohexylamine gave the dimer of nitrosocyclohexane (43%) when oxidized by MCPBA at 23 C, but at 83 C (in boiling 1,2-di-chloroethane) the only product was nitrocyclohexane (86%). 

Emmons and Pagano [75] succeeded in oxidizing oximes of alicyclic ketones with trifluoro peracetic acid to yield nitrocyclopentan and nitrocyclohexane with the yield of 60-62%. Oximes of steroids were oxidized with nitric acid-hydrogen peroxide to yield gem-dinitro derivative which under hydrogenation on platinum gave nitrosteroids with the nitro group in positions 3,4,6, 7 and 17 176). 

NITROCYCLOHEXANE (1122-60-7) C4H N02 Highly flammable liquid. Forms explosive mixture with air (flash point 166°F/74°C Fire Rating 3). An oxidizer. Violent reaction possible explosion, especially at high temperature and pressure ... 

Under suitable conditions it is possible to isolate the A-substituted hydroxylamines that are formed as intermediates in the reduction of nitro compounds. For this purpose it is essential in the reduction of aromatic nitro compounds to work with neutral or nearly neutral solutions suitable reducing agents are hydrogen and platinum oxide catalysts in glacial acetic acid,82,83 zinc dust in ammonium chloride solution,84 aluminum amalgam,85 and ammonium sulfide.86 Aliphatic nitro compounds may be reduced as their alkali salts (nitronates) by diborane in tetrahydrofuran, then giving A-alkylhydroxyl-amines 87 for instance, A-cyclohexylhydroxylamine is thus obtained from nitrocyclohexane in 53% yield. However, aliphatic nitro compounds are converted into A-alkylhydroxylamines more simply by catalytic hydrogenation in the presence of palladium-barium sulfate unlike aromatic nitro compounds, aliphatic nitro compounds require an acid medium for reduction to hydroxylamines an oxalic acid medium has proved the most suitable. 

Cycloalkanes are generally oxidized to straight-chain dicarboxylic acids only with great difficulty and then in poor yield. For example, on oxidation by nitric acid cyclohexane gives a mixture of 29% of adipic acid and 36% of nitrocyclohexane.101... 

Nitrocyclohexane has been prepared by E. I. du Pont de Nemours Company by nitration of cyclohexane. Cyclohexane undergoes nitration and oxidation to give nitrocyclohexane and adipic acid along with smaller amounts of glutaric acid and succinic add. Nitration is accelerated by the addition of nitrogen dioxide. The process may be operated continuously in the liquid phase with 45-75 per cent nitric acid at temperatures of 100-200 C and pressures of 2-10 atm. This process is of particular interest in that oxidation products from cycloalkanes are usually S3rmmetrical di-carboxylic acids, which are of industrial importance. 

Nitrogen Compounds. The aqueous Oxone-acetone combination has been developed for the transformation of certain anilines to the corresponding nitrobenzene derivatives, as exemplified in eq 15. This process involves sequential oxidation steps proceeding by way of an intermediate nitroso compound. In the case of primary aliphatic amines, other reactions of the nitrosoalkane species compete with the second oxidation step (for example, dimerization and tautomerization to the isomeric oxime), thereby limiting the synthetic generality of these oxidations. An overwhelming excess of aqueous Oxone has been used to convert cyclohexylamine to nitrocyclohexane (eq 16)P... 

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