Nitrocompounds, aliphatic

The characteristic property of aliphatic nitrocompounds of the type RCHiKOj and RjCHNO, is that they are pseiido cids, I. e., whereas they are neutral in the normal form (A), they are able by tautomeric change under the influence of alkali to give the acidic hydroxy form (B) which thus in turn gives the sodium salt (C). When this sodium salt is treated with one equivalent of hydrochloric acid, the acid form (B) is at once regenerated, and then more slowly reverts to the more stable normal form (A). 

Excellent yields of the oximes of phenylacetaldehydes are obtained by reduction of 6-nitrostyrenes over Pd-on-C in a pyridine solvent (74,75). The technique gives yields of only about 60% when applied to aliphatic unsaturated nitrocompounds better yields are obtained in acidic media(6 5). Over 5% Rh-on-Al203 in ethanol-acetic acid-ethyl acetate, 2- 6-dinitro-styrenes are converted to 2-nitrophenylacetaldehyde oximes (13). 

Thermal Stability. Satisfactory Refs 1) Beil—not found 2) L.F. Fieser, Aromatic, Aliphatic Nitrocompounds and Nitrate Esters , OSRD 176 (1941) 3) R. 

Bendova, M., Rehak, K.. Matous, J., and Novak, J.P. Liquid + liquid equilibrium in the ternary systems water + ethanol + dialkyl phthalate (dimethyl, diethyl, and dibutyl phthalate) at 298.15 K, /. Chem. Eng. Data, 46(6) 1605-1609, 2001. Benes M. andDohnal, V. Limiting activity coefficients ofsome aromatic and aliphatic nitrocompounds in water, / Chem. Eng. Data, 44(5) 1097-1102, 1999. 

The radical-anions of aliphatic nitrocompounds are detectable in aqueous solution as transient intermediates formed during continuous electrolysis in the cavity of the esr spectrometer [4], Decay of the species occurs by protonation and then further reactions. 2-Methyl-2-nitropropane has no acidic hydrogens so that it can be examined in aqueous alkaline solution where the radical-anion is not protonated. Over the pH range 9-11, this radical-anion decays by a first order process with k = 0.8 0.1 s at 26 C. Decay results from cleavage of the carbon-nitrogen bond to give a carbon centred radical and nitrite ion. Ultimately, the di-(ferr,-butyI)nitrone radical is formed in follow-up reactions [5],... 

The reduction of aliphatic nitrocompounds in acid solution proceeds in two steps. First the nitrosocompound is formed. A low steady state concen ation of 2-methyl-2-nitrosopropane has been detected during the reduction of 2-methyl-2-nitropropane [13]. At the cathode potential necessary to attach the first electron to a nitro group, the nitroso intermediate undergoes further reduction to the hydroxyla-mine. When the nitrocompound has one a-hydrogen substituent, tautomerism of the nitroso intermediate to an oxime is in competition with further reduction. Both temperature and proton availability affect the rate of this isomerisation. Reduction of aliphatic nitrocompounds to the hydroxylamine is usually carried out in acid solution at 0-5° C to minimise oxime formation [14, 15], The hydroxylamine is stable towards further reduction in acid solution. Oximes in acid solution are reduced... 

Alkalies, Action on Aliphatic Nitrocompounds. Compds with hydrogen atoms attached to a primary or secondary carbon atom linked to an NO, group show weakly acid properties. Such compds dissolve or react slowly in strong alkalies to form salts. This formation of salts is usually comparatively slow. 

Hydroxylamines are efficiently oxidized to nitrones with TPAP.91 Although aromatic nitrocompounds resist the action of TPAP,92 aliphatic nitrocompounds can suffer oxidation.93... 

Aromatic-Aliphatic Nitrocompounds and Nitrate Esters. Title of OSRD Report No 176, Nov 1941, by L, F, F leser... 

Gas chromatography has been applied to the determination of a wide range of organic compounds in trade effluents including the following types of compounds which are reviewed in Table 15.15 aromatic hydrocarbons, carboxylic acids aldehydes, non ionic surfactants (alkyl ethoxylated type) phenols monosaccharides chlorinated aliphatics and haloforms polychlorobiphenyls chlorlignosulphonates aliphatic and aromatic amines benzidine chloroanilines chloronitroanilines nitrocompounds nitrosamines dimethylformamide diethanolamine nitriloacetic acid pyridine pyridazinones substituted pyrrolidones alkyl hydantoins alkyl sulphides dialkyl suphides dithiocaibamate insecticides triazine herbicides and miscellaneous organic compounds. 

THERMAL DECOMPOSITION OF ALIPHATIC NITROCOMPOUNDS G.M.Nazin, G.B.Manelis... 

The review covers in systematic form the literature data on the thermal decomposition of aliphatic nitrocompounds amassed over the past 25 years. Molecular structure effects on the rate and mechanism of gas phase reactions, transition state structures of bond dissociation and HNO2 elimination, the main features of decomposition in condensed phase, the data on C—N bond energy and its dependence from electronic, steric and conformational effects are considered. 

Aliphatic Nitrocompounds as Versatile Building Blocks for the One-Pot Processes... 

The aim of this chapter is to show some representative examples in which aliphatic nitrocompounds are the key starting materials for the synthesis of different targets in a one-pot process. Thus, the availability of a variety of nitroalkenes and nitro-alkanes, their chemical versatility and their reactivity make these compounds highly powerful precursors and intermediates in environment-friendly organic synthesis. 

Reactions of heterocycles with aliphatic nitrocompounds 88CSR283. 

---