Nitro, acids methane

Methylnitrolic Acid (Nitromefhane oxime, nitroformaldoxime, nitro-oosimino-methane, niiro-isonltroso-rnethane)... 

CH,),CHNO, -h HONO = (CH,),C(NO)NO, -h H,0 producing a blue solution. A tertiary nitro paraffin such as trimethylnitro-methane, (CH )jCNO, gives no reaction with nitrous acid. 

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. 

Under these first-order conditions the rates of nitration of a number of compounds with acetyl nitrate in acetic anhydride have been determined. The data show that the rates of nitration of compounds bearing activating substituents reach a limit by analogy with the similar phenomenon shown in nitration in aqueous sulphuric and perchloric acids ( 2.5) and in solutions of nitric acid in sulpholan and nitro-methane ( 3.3), this limit has been taken to be the rate of encounter of the nitrating entity with the aromatic molecule. 

Strong acids or superacid systems generate stable fluorinated carbocations [40, 42] Treatment of tetrafluorobenzbarrelene with arenesulfonyl chlorides in nitro-methane-lithium perchlorate yields a crystalline salt with a rearranged benzo barrelene skeleton [43] Ionization of polycyclic adducts of difluorocarbene and derivatives of bornadiene with antimony pentafluonde in fluorosulfonyl chloride yields stable cations [44, 45]... 

Nitro-1.2-dihydro-2-(N-methylpiperazin-1-vl)methylene-6-(o-chlorophenyl)-1 H,4H-imidazo[1.2-a] [1,4] benzodiazepin-1 -one Methane sulfonic acid... 

Figure 15. Disproved isokinetic relationship for the proton transfer from nitro-methane to various carboxylic acid anions (156). Symbols as in Figure 13.

On the other hand, CH-acidic solvents such as acetylacetone, acetonitrile, nitro-methane, and dimethyl sulfoxide (Entries 25-28) yield stable crystal inclusions, each having a strict 1 1 stoichiometry. Finally, respective crystallization experiments using solvents of even less polarity or ability to form H-bonds have been carried out. The... 

D-glucuronic acid in, VIII, 251-275 Methane, nitro-, syntheses with, VI, 291-318 Methyl ethers. See Ethers, methyl. Molasses, cane, III, 113-128... 

Nitro-groups can also be introduced into side chains.1 If toluene or ethylbenzene, for example, is heated with dilute nitric acid (d. 1-076) in a closed vessel to a temperature somewhat over 100° phenylnitro-methane C 6Hs.CH2.N02 or phenylnitroethane C6H5.CH(N02).CH3 is obtained. 

On treatment of glutaraldehyde with 2-hydroxy-3-nitropropionic acid, only 2-nitrocyclohexane-l,3-diol could be isolated in 10% yield, indicating that, under the conditions used, a retro-aldol degradation takes place with liberation of nitromethane. However, when using methyl 2-methoxy-3-nitropropionate, which cannot undergo a retro-nitro-methane addition", products (101) and (102) are obtained in yields of 7 and 13% respectively... 

Nitration can also be carried out in organic solvents, with acetic acid and nitro-methane being common examples. In these solvents, the formation of the N02+ ion is often the rate-controlling step1 ... 

The solvent affects the chemical equilibria of reactions. Second-order rate constants and equilibrium constants have been determined for the benzoate ion promoted deprotonation reactions of (m-nitrophenyl)nitromethane, (p-nitrophenyl)nitromethane, and (3,5-dinitrophenyl)nitromethane in methanol solution. The pKa values for the arylnitromethanes in methanol are the following pKa = 10.9, 10.5, and 9.86 for m-nitrophenyl)nitromethane, (p-nitrophenyl)nitromethane, and (3,5-dinitrophenyl)nitro-methane, respectively, relative to benzoic acid (pKa = 9.4). A Bronsted B value of... 

It is rather surprising to find a compound with only one activating group among the others, but the nitro group is very electron-withdrawing so that the pK of nitro-methane is 10 it is even more acidic than most dicarbonyl compounds. Go to frame 268. 

The most important reactions of nitroalkan.es are those involving the a hydrogens of the primary and secondary compounds. For example, nitro-methane is sufficiently acidic to dissolve in aqueous hydroxide solutions. The anion so produced has an electronic structure analogous to the nitrate anion ... 

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