Of nitromethane

In view of the small volume of nitromethane to be manipulated, the crude nitromethane may be extracted from the aqueous distillate with ether (30-40 ml.). Dry the ethereal extract over sodium sulphate, filter through a fluted filter-paper, and then distil off the ether on a water-bath with the usual precautions (Fig. 64, p. 163 Fig, 23(E), p. 45) finally distil the residual nitromethane. 

Reactions of Nitromethane. (1) Nitromethane, although only slightly soluble in cold water, is freely soluble in sodium hydroxide solution, the alkaline solution slowly becoming yellow in colour. 

Place a few drops of nitromethane in a test tube, add about 3 times as much concentrated hydrochloric acid, and then a piece of granulated tin. The tin dissolves in the acid and the nascent hydrogen produced reduces the nitromethane to monomethylamine ... 

Dissolve a few drops of nitromethane in 10% sodium hydroxide solution. Add a few crystals of sodium nitrite and shake. Now add dilute sulphuric acid drop by drop. A brownish-red coloration develops, but fades again when an excess of acid is added. The sulphuric acid has thus liberated nitrous acid, which has in turn reacted with the nitromethane to give a nitrolic acid, the sodium salt of which is CH3NO2 + ONOH = CH(N02) N0H + HgO reddish-brown in colour, probably owing to mesomeric ions of the type ... 

Nitration in acetic acid, in sulpholan and in carbon tetrachloride showed kinetic phenomena similar to those shown in nitromethane this is significant for it denies nitromethane a chemical involvement in the slow step. (Originally the rate of isomerization of nitromethane to its aci-form was believed to be a factor in the reaction. )... 

The more strongly acidic a solution of nitric acid at a given concentration is in a particular organic solvent, the more readily should that solvent support zeroth-order nitration. The values of for solutions of sulphuric acid in nitromethane, sulpholan, and acetic acid show clearly the superiority of nitromethane in this respect. ... 

The relative abilities of nitromethane, sulpholan, and acetic acid to support the ionisation of nitric acid to nitronium ions are closely similar to their efficiencies as solvents in nitration. Raman spectroscopy showed that for a given concentration of mixed acid (i i nitric and sulphuric acids) the concentration of nitronium ions in these three solvents varied in the order nitromethane > sulpholan > acetic acid. The concentration of mixed acid needed to permit the spectroscopic detection of nitronimn ions was 25 %, 50 % and 60 % in the three solvents, respectively (see 4.4.3). 

So, how does this whole thing work It s as simple as it sounds. An alcoholic solution of nitromethane and MDP2P is dripped into a mass of amalgamated aluminum immersed in alcohol first reducing the nitromethane to methylamine, allowing the Schiff base of the amine and ketone to form which is then further reduced to the desired MDMA. 

Nitromethane is stabilized by electron delocalization more than methyl nitrite is The two most stable resonance forms of nitromethane are equivalent to each other... 

The concentration of nitromethane, CH3NO2, can be determined from the kinetics of its decomposition in basic solution. In the presence of excess base the reaction is pseudo-first-order in nitromethane. For a standard solution of 0.0100 M nitromethane, the concentration of nitromethane after 2.00 s was found to be 4.24 X 10 M. When a sample containing an unknown amount of nitromethane was analyzed, the concentration remaining after 2.00 s was found to be 5.35 X 10 M. What is the initial concentration of nitromethane in the sample ... 

Equation 13.6 can then be solved for the initial concentration of nitromethane. This is easiest to do using the exponential form of equation 13.6. 

Nitromethane [75-52-5] is produced in China. Presumably a modified Victor Meyer method is being employed. Nitromethane is transported in dmms or smaller containers. Two tank cars of nitromethane exploded in separate incidents in the 1950s. Both explosions occurred in the switching yard of a railroad station. In both cases, essentially adiabatic vapor compression of the nitromethane—air mixture in the gas space of the tank car resulted in the detonation of the Hquid nitromethane. Other nitroparaffins do not, however, detonate in this manner. 

The thermal characteristics of higher nitroparaffins are quite different from those of nitromethane. The nitropropanes provide neatly twice as much heat as does nitromethane when burned in air or oxygen. When the only source of oxygen is that contained within the molecule, nitropropanes yield only 20% as much energy as nitromethane on burning. 

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. 

The insensitivity of nitromethane to detonation by shock under normal conditions of handling has been demonstrated by a number of fljH-scale tests. Sensitivity to shock increases with temperature at 60° C, nitromethane can be detonated by a No. 8 blasting cap. Nitroethane can be initiated only when heated near its boiling point under heavy confinement neither it or the nitropropanes can be detonated in unconfined conditions. 

Environmental Concerns. Few data on the environmental effects of the nitroparaffins are available. However, they are known to be of low toxicity to the fathead minnow (109). Based on their uv spectra, the nitroparaffins would be expected to undergo photolysis in the atmosphere. The estimated half-life of 2-nitropropane in the atmosphere is 3.36 h (110). Various values have been determined for the half-life of nitromethane, but it is similar to 2-nitropropane in persistence (111). Reviews of the available data on the environmental effects of nitromethane and 2-nitropropane have been pubhshed by the U.S. Environmental Protection Agency (112,113). 

Halogenation of nitromethane is utilized to produce two economically important pesticides, chloropicrin [76-06-2J, a soil fumigant, and bronopol, a biocide useful for control of microbial growth in cosmetics and industrial appHcations. 

Significant quantities of nitromethane find use as fuel in drag racing and as a hobby fuel. In addition, nitromethane is used in explosive appHcations, particularly in shaped charges for specialized appHcations. It has the advantage of not in itself being classified as an explosive, but it can be made cap-sensitive on-site, thus simplifying the transport of the explosive system to remote locations. 

Only small amounts of nitromethane are used as solvent, but it is used in specialized appHcations such as the solublization of a-cyanoacrylate glue and acryhc polymers. Also, nitromethane is useflil as solvent for single-phase Friedel-Crafts reactions (115). 

Methylene chloride is one of the more stable of the chlorinated hydrocarbon solvents. Its initial thermal degradation temperature is 120°C in dry air (1). This temperature decreases as the moisture content increases. The reaction produces mainly HCl with trace amounts of phosgene. Decomposition under these conditions can be inhibited by the addition of small quantities (0.0001—1.0%) of phenoHc compounds, eg, phenol, hydroquinone, -cresol, resorcinol, thymol, and 1-naphthol (2). Stabilization may also be effected by the addition of small amounts of amines (3) or a mixture of nitromethane and 1,4-dioxane. The latter diminishes attack on aluminum and inhibits kon-catalyzed reactions of methylene chloride (4). The addition of small amounts of epoxides can also inhibit aluminum reactions catalyzed by iron (5). On prolonged contact with water, methylene chloride hydrolyzes very slowly, forming HCl as the primary product. On prolonged heating with water in a sealed vessel at 140—170°C, methylene chloride yields formaldehyde and hydrochloric acid as shown by the following equation (6). 

For materials with very low melting points it is sometimes convenient to use dilute solutions in acetone, methanol, pentane, diethyl ether or CHCI3-CCI4. The solutions are cooled to -78° in a dry-ice/acetone bath, to give a slurry which is filtered off through a precooled Buchner funnel. Experimental details, as applied to the purification of nitromethane, are given by Parrett and Sun [J Chem Educ 54 448 7977]. 

A mixture of nitromethane and hexafluorobenzene, when thermolyzed at 550 °C, yields pentafluorotoluene and pentafluorophenol as major products- The formation of nitrosyl and mtryl fluondes is probably a dnving force in this transfor-madon [705] A potential general preparative route to various perfluorovmyl amines is pyrolytic decarboxylation of potassium salts of perfluoro-2-(dialky-... 

The effectiveness of nitromethane can be attributed to its high dielectric constant, at least in part, which tends to promote reactions which involve electron-rich intermediates. It may also result from the low solubility of the indole products in nitromethane since the indoles precipitate out of the reaction mixture in many cases. ... 

A convenient method leading to pyrans (38) consists in the nucleophilic addition of R anions to 2,6-disubstituted pyrjdium salts, in which the y-position (secondary carbonium ion) is more reactive than the a-positions (tertiary carbonium ions), in opposition to the reactivity of 2,4,6-trisubstituted pyrylium salts.Krohnke and Dickore as well as Dimroth and WolH showed that 2,6-diphenyl-pyrylium salts add the anions R of nitromethane, 1,3-diketones, malonodinitrile, ethyl cyanoacetate, and benzoylacetonitrile. Similar reactions are known in the flavylium series. -Nonactivated R ... 

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 ... 

Seebach and coworkers have developed the rtmldple coupling reagent, 2-tiitro-2-propenyl 2,2-dimethylpropanoate fNPPi. The reaction of nitromethane v/ith formaldehyde gives 1,3-dihydroxy-2-nitropropane in 95% yield. Subsequent acyladon v/ith two eqidviilents of pivaloyl chloride and elimination of pivalic acid affords NPP. The reacdon may be run on a 40- to 200-g... 

The base-catalyzed reacdon of nitromethane with ct-amidoalkyl sulfones gives the nitto compounds as in Eq 4 117 the nitromethyl group is converted into a carboxylic group to give ct-amino acids by the Nef reacdon using KMnO. ... 

The Michael addition of nitromethane to vinylogons esters of iV-protected amino acids proceeds v/ith good yields and v/ith good diastereoselecdvity fEq. 4.135. ... 

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