A—NITRO COMPOUNDS

Reduction of a nitro compound to a hydroxylamine. Dissolve 0-5 g. of the compound in 10 ml. of 50 per cent, alcohol, add 0-5 g. of solid ammonium chloride and about 0 5 g. of zinc powder. Heat to boiling and allow the ensuing chemical reaction to proceed for 5 minutes. Filter from the excess of zinc powder and test the filtrate with ToUen s reagent see Section III,70,(i). An immediate black or grey precipitate or a silver mirror indicates the presence of a hydroxylamine formed by the reduction of the nitro compound. Alternatively, warm the filtrate with Fehling s solution a hydroxylamine will precipitate red cuprous oxide. (A blank test should be performed with the original compound.)... 

Reduction of a nitro compound to a primary amine. In a 50 ml. round-bottomed or conical flask fitted with a reflux condenser, place 1 g. of the nitro compound and 2 g. of granulated tin. Measure out 10 ml. of concentrated hydrochloric acid and add it in three equal portions to the mixtiue shake thoroughly after each addition. When the vigorous reaction subsides, heat under reflux on a water bath until the nitro compound has completely reacted (20-30 minutes). Shake the reaction mixture from time to time if the nitro compound appears to be very insoluble, add 5 ml. of alcohol. Cool the reaction mixture, and add 20-40 per cent, sodium hydroxide solution imtil the precipitate of tin hydroxide dissolves. Extract the resulting amine from the cooled solution with ether, and remove the ether by distillation. Examine the residue with regard to its solubility in 5 per cent, hydrochloric acid and its reaction with acetyl chloride or benzene-sulphonyl chloride. 

Reduction of a nitrosamine to a secondary amine. Proceed as for a nitro compound. Determine the solubility of the residue after evaporation of the ether and also its behaviour towards benzenesulphonyl (or p-toluenesulphonyl) chloride. 

Given a nitrogen containing organic compound such as an amide a nitnle or a nitro compound how is the correct oxidation state of the desired amine to be achieved" ... 

Reduction of an azide a nitrile or a nitro compound furnishes a primary amine A method that provides access to primary secondary or tertiary amines is reduction of the carbonyl group of an amide by lithium aluminum hydride... 

By treating this blue nitrosite, which Deussen calls )3-caryophyllene nitrosite, with alcoholic potash at 0°, it is converted to a colourless isomer, melting at 139°, which Deussen terms )3-caryophyllene isonitrosite. By treatment with boiling petroleum ether decomposition takes place and a compound melting at 159° is formed, of formula not yet established, and a nitro-compound of the formula Cj5H22N204, melting at 130 5°. 

Paeonol forms a nitro-compound CgHgOgN, melting at 153° to 155°. Hydroxypaeonol, CjHjqO, has also been found in essential oils of the XanthoirhoM species. It melts at 79°. 

Musk ambrette, which is usually regarded as the finest of all the artificial musks, is a nitro-compound of the methyl ether of butyl-meta-cresol, usually described as dinitro-butyl- ieia-cresol methyl ether. It should melt at 85°. 

Reduction of aromatic nitro compounds may give products sensitive to air. Moder and Leonard (d5) stressed the importance of rigid exclusion of air during reduction of a nitro compound to a complex air-sensitive diamine in order to maximize the yield. It is quite likely that in these cases the oxidation products will have an adverse influence on catalyst life. 

In Figure 22.2, the abundance of the molecular ion at m/z 138 suggests an aromatic compound. Examining the losses from the molecular ion (M-46 and M-30) shows that it is a nitro compound. Because the molecular ion is of even mass, an even number of nitrogen atoms must be present. Looking up m/z 92 in Part III for possible structures, the following is suspected ... 

The behaviour [821] of AgN02 is closer to that expected of a nitro compound than a nitrite. Decomposition (308—363 K) yields Ag metal and N02. a—Time curves are sigmoid with a prominent linear region (0.15 < a < 0.45) but the Arrhenius plot was curved at >333 K. This was attributed to inadequate gaseous product removal. In contrast to the behaviour observed for most other solids, pre-irradiation with 7-rays inhibits subsequent thermal decomposition [829]. 

Figure 7. Nucleophilic displacement of nitrite from a nitro compound, from...

Figure 8, Photolytic generation of nitrogen dioxide and an aryl nitrite ester from a nitro compound, as formulated by Lippert and Kelm (27),...

The transformation of A-nitrosodimethylamine by Pseudomonas mendocina KRl that has tolu-ene-4-monoxygenase activity was initiated by monooxygenation to the A-nitro compound, which produced A-nitromethylamine and formaldehyde, presumably by hydroxylation of the methyl group (Fournier et al. 2006). 

Aromatic nitro and nitroso compounds are easily reduced at carbon and mercury electrodes. Other nitro compounds such as nitrate esters, nitramines, and nitrosamines are also typically easily reduced. The complete reduction of a nitro compound consists of three two-electron steps (nitro-nitroso-hydroxylamine-amine). Since most organic oxidations are only two-electron processes, higher sensitivity is typically found for nitro compounds. Several LCEC based determination of nitro compounds have been reported... 

See other a-metal derivatives, a-nitro compounds, silver compounds... 

See entry nitramine- metal complexes See other a-nitro compounds, tetrazoles... 

See Other A-NITRO COMPOUNDS, PERCHLORATE SALTS OF NITROGENOUS BASES... 

A sample exploded on vacuum distillation at 60° C, though not at 40°C/33 mbar. See Other A-HALOGEN COMPOUNDS, A-NITRO COMPOUNDS... 

Wilier, R. L. et al., J. Heterocycl. Chem., 1992, 29(7), 1835 An explosive of moderate sensitivity, thermally decomposing (non-explosively) from 120°C. The 4-nitro analogue was also explosive and decomposed from 90°C. See Other A-NITRO COMPOUNDS, HIGH NITROGEN COMPOUNDS... 

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