Dinitrogen tetroxide reactions with

Dinitrogen tetroxide reacts with simple alcohols in the gas and liquid phase to yield the corresponding nitrite ester as the major product together with trace amounts of oxidation products (Equation 3.4). This is the case for neat reactions and those conducted in methylene chloride between subambient and ambient temperatures. 

Combustible liquid (flash point 230°F/110°C cc). Ignites spontaneously in air. Sunlight causes rapid decomposition. Reacts with water or steam, producing toxic and flammable vapors. Violent reaction with strong oxidizers, dinitrogen tetroxide. Incompatible with strong acids, hydroxylamine. 

The photochemical reaction of Re2(CO)io with PMePhg seems to fit into this two-equilibrium scheme fairly well, and so represents a recently discovered example of substitution at M2(CO)io without metal-metal bond cleavage. Dinitrogen tetroxide reacts with Re2(CO)io to cleave the metal-metal bond and give ultimately Re(N03)(C0)5, by the following sequence ... 

The catalysed nitration of phenol gives chiefly 0- and />-nitrophenol, (< 0-1% of w-nitrophenol is formed), with small quantities of dinitrated compound and condensed products. The ortho para ratio is very dependent on the conditions of reaction and the concentration of nitrous acid. Thus, in aqueous solution containing sulphuric acid (i 75 mol 1 ) and nitric acid (0-5 mol 1 ), the proportion of oriha-substitution decreases from 73 % to 9 % as the concentration of nitrous acid is varied from o-i mol l i. However, when acetic acid is the solvent the proportion of ortAo-substitution changes from 44 % to 74 % on the introduction of dinitrogen tetroxide (4-5 mol 1 ). 

In solutions of acetyl nitrate in acetic anhydride, prepared from purified nitric acid, the 0 -ratio increases slightly with increasing concentrations of acetyl nitrate (table 5.7, expts. 11,13,16). The use of fuming nitric acid in the preparation of the acetyl nitrate considerably accelerates the rates of reaction and also increases the proportion of o-substitution (table 5.7, expts. 12, 15, 18). These effects resemble, but are much stronger than the corresponding effects in nitrations with solutions of nitric acid in acetic acid contaimng dinitrogen tetroxide. 

Several derivatives of cellulose, including cellulose acetate, can be prepared in solution in dimethylacetamide—lithium chloride (65). Reportedly, this combination does not react with the hydroxy groups, thus leaving them free for esterification or etherification reactions. In another homogeneous-solution method, cellulose is treated with dinitrogen tetroxide in DMF to form the soluble cellulose nitrite ester this is then ester-interchanged with acetic anhydride (66). With pyridine as the catalyst, this method yields cellulose acetate with DS < 2.0. 

Many other reactions of ethylene oxide are only of laboratory significance. These iaclude nucleophilic additions of amides, alkaU metal organic compounds, and pyridinyl alcohols (93), and electrophilic reactions with orthoformates, acetals, titanium tetrachloride, sulfenyl chlorides, halo-silanes, and dinitrogen tetroxide (94). 

In the photolysis of difiuorodiazirine (218) a singlet carbene was also observed (65JA758). Reactions of the difiuorocarbene were especially studied with partners which are too reactive to be used in the presence of conventional carbene precursors, such as molecular chlorine and iodine, dinitrogen tetroxide, nitryl chloride, carboxylic acids and sulfonic acids. Thus chlorine, trifiuoroacetic acid and trifiuoromethanesulfonic acid reacted with difiuorodiazirine under the conditions of its photolysis to form compounds (237)-(239) (64JHC233). 

B. N-Nitroso-N-(2-phenylethyl)benzamide. A solution of 10.4 g. (0.046 mole) of the crude N-(2-phenylethyl)benzamide, 7.36 g. (0.09 mole) of anhydrous sodium acetate, and-50 ml. of glacial acetic acid is placed in a 250-ml. Erlenmeyer flask equipped with a drying tube, and the mixture is cooled to the crystallization point of the acetic acid (Note 1). A solution of dinitrogen tetroxide (Notes 2, 3) in glacial acetic acid (85 ml. of a solution approximately 1M in N2O4) is then added with stirring. The reaction mixture is allowed to warm to about 15° (15 minutes), and then it is poured into a mixture of ice and water. The yellow solid nitroso derivative is dissolved in 75 ml. of carbon tetrachloride, and this solution is washed with 5% sodium bicarbonate, water, and dried. The solution is used directly in the next step. 

Nitrosation, of amides with dinitrogen tetroxide, 47, 46 of N phenylglycine, 46, 96 p-Nitrosodimethylamhne, reaction with o nitrobenzylpyndimum bro mide, 46,82... 

C. By Oxidation.—This year s literature has been notable for attempts to study the details of certain phosphine oxidation reactions. In one such investigation nitric acid was found to oxidize phosphines, or phosphine sulphides, to phosphine oxides with inversion of configuration at phosphorus, whereas dinitrogen tetroxide, in the absence of acid, was found to oxidize the same compounds with predominant retention. The partial racemization observed with the latter reagent was probably due to the racemization of the oxides, since methylphenyl-n-propylphosphine oxide... 

Nitrogen dioxide forms an equilibrium with dinitrogen tetroxide. When it is cold, the equilibrium favours the second compound. Depending on the thermal conditions, the dangerous reactions will involve one or the other of these two compounds. Their endothermic character makes them hardly stable. 

Dinitrogen tetroxide has a highly exothermic reaction with boron trichloride. 

A reaction of dinitrogen tetroxide with acetonitrile in the presence of indium was carried out. The technician wanted to accelerate the process by stirring the medium, causing ils detonation. This accident was put down to the vioient oxidation of the acetonitrile accumulated, by nitrogen oxide catalysed by indium. 

Dinitrogen tetroxide gives rise to a violent reaction with dimethyisulphoxide. This reaction can lead to a detonation. The same happens when using nitric acid that contains less than 14% of water. In both cases, the reaction should form dimethylsulphone. 

Recently, nitration of organolithiums and Grignards with N204 has been developed for the preparation of certain kinds of nitro compounds (Eqs. 2.14 and 2.15).31 The success of this process depends on the reaction conditions (low temperature) and the structure of substrates. For example, 3-nitrothiophene can be obtained in 70% overall yield from 3-bromothiophene this is far superior to the older method. 3-Nitroveratrole cannot be prepared usefully by classical electrophilic nitration of veratrole, but it can now be prepared by direct o>7/ o-lithiation followed by low-temperature N204 nitration. The mechanism is believed to proceed by dinitrogen tetroxide oxidation of the anion to a radical, followed by the radical s combination. 

To the best of the author s knowledge, the only isolated diaza analog of o-benzoquinone is bis-N-oxide 79 and its derivatives. Compound 79 was isolated as orange-colored crystals from a reaction of tetraketo derivative 78 with dinitrogen tetroxide (76TL1703 77AP264). 

The reactions of diazoesters with hydrochloric and sulfuric acids, triphenylphosphine, and dinitrogen tetroxide resulted in aryl chloroacetates, bis(aryloxycarbonylmethyl) sulfates, triphenylphosphoranylidenehydrazones of aryl 2-oxoethanoates, and iV-oxides of diaryl l,2,5-oxadiazole-3,4-dicarboxylates <1999RJO 666>. 

Thioanisole, oxidation, by dinitrogen tetroxide, 46,80 by hydrogen peroxide, 46, 80 by lead tetraacetate, 46, 80 reaction with sodium metaperiodate to form methyl phenyl sulfoxide, 46,78... 

The reaction of a-nitroalkenes with nitrogen dioxide or its dimer, dinitrogen tetroxide, has been used to synthesize polynitroalkanes. Thus, the reaction of dinitrogen tetroxide with 2,3-dinitro-2-butene (6) and 3,4-dinitro-3-hexene is reported to yield 2,2,3,3-tetranitrobutane (7, 25 %) and 3,3,4,4-tetranitrohexane (32 %) respectively. ... 

The reaction of alkynes with dinitrogen tetroxide is less synthetically useful as a route to nitro compounds. The reaction of 3-hexyne with dinitrogen tetroxide yields a mixture of cis- and fran -3,4-dinitro-3-hexene (4.5% and 13% respectively), 4,4-dinitro-3-hexanone (8%), 3,4-hexanedione (16%) and propanoic acid (6%). 2-Butyne forms a mixture containing both cis- and fran -2,3-dinitro-2-butene (7 % and 34 % respectively). " ... 

The Ponzio reaction provides a useful route to gem-dinitro compounds and involves treating oximes with a solution of nitrogen dioxide or its dimer in diethyl ether or a chlorinated solvent. The Ponzio reaction works best for aromatic oximes where the synthesis of many substituted aryldinitromethanes have been reported. Compound (56), an isomer of TNT, is formed from the reaction of dinitrogen tetroxide with the oxime of benzaldehyde (55) followed by mononitration of the aromatic ring with mixed acid. Yields are usually much lower for aliphatic aldoximes and ketoximes. " The parent carbonyl compound of the oxime is usually the major by-product in these reactions. 

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