Nitro nitromethane

Nitromethane, CH3NO2, the first member of the homologous series, can, however, be readily prepared by a special reaction. When equimolecular amounts of sodium nitrite and sodium monochloroacetate are heated together in aqueous solution, the chlorine in the monochloroacetate is replaced by the nitro group, and the sodium nitroacetate thus formed undergoes hydrolysis follow ed by decarboxylation ... 

The simpler nitrop>arafIins (nitromethane, nitroethane, 1- and 2-nitroproj)ane) are now cheap commercial products. They are obtained by the vapour phase nitration of the hydrocarbons a gaseous mixture of two mols of hydrocarbon and 1 mol of nitric acid vapour is passed through a narrow reaction tube at 420-476°. Thus with methane at 476° a 13 per cent, conversion into nitro methane is obtained ethane at 420° gives a 9 1 mixture of nitroethane (b.p. 114°) and nitromethane (b.p. 102°) propane at 420° afifords a 21 per cent, yield of a complex mixture of 1- (b.p. 130-6°) and 2-nitropropane (b.p. 120°), nitroethane and nitromethane, which are separated by fractional distillation. 

Nitro compounds. Nitromethane Nitrobenzene ni-Dinitrobenzene. Amides and imides. Acetamide re-Caproamide Acetanilide Benz-anilide Phthalimide. 

Cydopentane reagents used in synthesis are usually derived from cyclopentanone (R.A. Ellison, 1973). Classically they are made by base-catalyzed intramolecular aldol or ester condensations (see also p. 55). An important example is 2-methylcydopentane-l,3-dione. It is synthesized by intramolecular acylation of diethyl propionylsucdnate dianion followed by saponification and decarboxylation. This cyclization only worked with potassium t-butoxide in boiling xylene (R. Bucourt, 1965). Faster routes to this diketone start with succinic acid or its anhydride. A Friedel-Crafts acylation with 2-acetoxy-2-butene in nitrobenzene or with pro-pionyl chloride in nitromethane leads to acylated adducts, which are deacylated in aqueous acids (V.J. Grenda, 1967 L.E. Schick, 1969). A new promising route to substituted cyclopent-2-enones makes use of intermediate 5-nitro-l,3-diones (D. Seebach, 1977). 

The telomer obtained from the nitromethane 65 is a good building block for civetonedicarboxylic acid. The nitro group was converted into a ketone, and the terminal alkenes into carboxylic acids. The acyloin condensation of protected dimethyl dvetonedicarboxylate (141) afforded the 17-membered acyloin 142, which was modified to introduce a triple bond 143. Finally, the triple bond was reduced to give civetone (144)[120). 

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]. 

The acid chloride of i i7-nitromethane, CH2=N(C1)0 (mp —43°C, bp 2—3°C), is formed by fusion of nitromethane and picrylpyridinium chloride (36). It is hydroly2ed to nitro some thane, reduces potassium permanganate strongly, and exhibits no reactions characteristic of hydroxamic acids. 

Most nitroparaffins do not react with ketones, but ia the presence of alkoxide catalysts, nitromethane and lower aUphatic ketones give nitro alcohols ia the presence of amine catalysts dinitro compounds are obtained. 

High performance Hquid chromatography (hplc) may be used to determine nitroparaffins by utilizing a standard uv detector at 254 nm. This method is particularly appHcable to small amounts of nitroparaffins present, eg, in nitro alcohols (qv), which caimot be analyzed easily by gas chromatography. Suitable methods for monitoring and deterrnination of airborne nitromethane, nitroethane, and 2-nitropropane have been pubUshed by the National Institute of Occupational Safety and Health (NIOSH) (97). Ordinary sorbant tubes containing charcoal are unsatisfactory, because the nitroparaffins decompose on it unless the tubes are held in dry ice and analyzed as soon after collection as possible. 

Nitromethane. The nitroparaffins are used widely as raw materials for synthesis. Nitromethane is used to produce the nitro alcohol (qv) 2-(hydroxymethyl)-2-nitro-l,3-propanediol, which is a registered biocide useful for control of bacteria in a number of industrial processes. This nitro alcohol also serves as the raw material for the production of the alkanolamine (qv) 2-amino-2-(hydroxymethyl)-l,3-propanediol, which is an important buffering agent useful in a number of pharmaceutical appHcations. 

Nitrofurantoin. The urinary tract antibacterial, l-[(5-nitro-2-furanyl)-methyleneamino]-2,4-imidazohdinedione, is prepared by reaction of 5-nitro-2-furancarboxaldehyde with l-anaino-2,4-imidazohdinedione (19,40). Crystallization of the material from nitromethane provides a macrocrystalline form (41) which continues to be employed clinically. 

Tris-(hydroxymethyl)nitromethane [2-(hydroxymethyl)-2-nitro-l,3-propanediol] [126-11-4] M 151.1, m 174-175°(dec, tech grade), 214°(pure). Crystd from CHCl3/ethyl acetate or ethyl acetate/ benzene. It is an acid and a O.IM sol in H2O has pH 4.5. IRRITANT. 

Nitric acid, 98 Nitric oxide, 98 Nitrilotriacetic acid, 98 p-Nitroaiiiline, 99 Nitrobenzene, 99 Nitrocarbono SA, 146 Nitrocellulose, 99 p-Nitrochlorobenzene, 99 Nitroethane, 99 Nitrofen, 99 Nitrogen, 99 Nitrogen dioxide, 99 Nitrogen oxides, 99 Nitrogen trifluoride, 99 Nitroglycerin, 100 Nitrokemia 200 Rt., 167 Nitromethane, 100 5-Nitro-o-anisidine, 99 5-Nitro-o-toluidine, 100 Nitrophenols, 100... 

The starting material for the Tiffeneau-Demjanov reaction is available by various methods. A common route is the addition of nitromethane to a cyclic ketone—e.g. cyclopentanone 7—followed by a hydrogenation of the nitro group to give the /3-amino alcohol, e.g. 1 ... 

Proazaphosphao-ane, PrRNCH-,CH-j,N, is an efficient catalyst for the Henty reacdon, and arious ketones give nitro-aldols by the reacdon with nitromethane and other nitroalkanes fEq. 

Allylic nitro compounds are obtained by the reacdon of cyclic ketones with nitromethane in the presence of 1,2-diaminoethane fl mol% as catalyst. Because exa-cyclic nitroalkenes are rearranged to the fi)iifo-cyclic fi,Y-nitroalkenes, allylic nitro compounds are selecdvely produced fEq. 3.21. ... 

The catrilydc asymmetric nitro Mannich-type reac blnaphthol gives the best result fsee Eq 4 141 The re a good ee, where nitromethane is added vety slowly ovei... 

C-Alkyldtkin takes place in the reaction of methyl nitroacetate with ilkyl h ilicles the products are useful intermediates for preparing amino acids fEq. 5.1 /The requisite nitro acetate is prepared by seif condensadon of nitromethane. ... 

Recently, elegant synthesis of ruin -MRS carbapenum has been reported. Sequential reaction of nitromethane via conjugate addition-elimination to a,fi-unsanirated esters followed by Pd-catalyzed subsdnidon of the residdng allyl nitro compound with the naphthosultam affords the allyladon product which is an and fEq. 7.20. ... 

The Michael dclclidon of nitro ilkdnes followed by denitration is also a useful method fot the pteparadon of C-disaccharide. The Michael addidon of glncosyl nitromethane to the levogln-cosenone ptoceeds steteoselecdvely, and subsequent denitradon gives the C-disaccharide in 68% yield fScheme 1.%) ... 

Nitrating propane produces a complex mixture of nitro compounds ranging from nitromethane to nitropropanes. The presence of lower nitroparaffins is attributed to carbon-carbon bond fission occurring at the temperature used. Temperatures and pressures are in the range of 390°-440°C and 100-125 psig, respectively. Increasing the mole ratio of propane to nitric acid increases the yield of nitropropanes. Typical product composition for 25 1 propane/acid ratio is ... 

Another early example is nitromethane which is special in two respects. First, the barrier has sixfold symmetry because of the threefold character of the methyl group and the twofold character of the nitro group. Secondly, the barrier turns out to be extremely low, only about 5 small calories. For such a low barrier, it is convenient to treat the coupling between free internal rotation and overall rotation exactly and consider the barrier as a small perturbation. 

Starting from the appropriately substituted carbohydrates (e.g., II), 1,5-dialdehydcs are obtained by periodate oxidation. Subsequent double Henry reaction33 with nitromethane furnishes a variety of nitro-substituted carbohydrate derivatives. In most cases pure stereoisomers are obtained by crystallization of the reaction mixture3. 

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