Structural details ofnitrobenzene, distances in picometers.[2]
Aromatic nitro compounds are typically synthesized by nitration. Nitration is achieved using a mixture ofnitric acid andsulfuric acid, which produce thenitronium ion (NO+2), which is the electrophile:
+
H+
The nitration product produced on the largest scale, by far, isnitrobenzene. Many explosives are produced by nitration includingtrinitrophenol (picric acid),trinitrotoluene (TNT), andtrinitroresorcinol (styphnic acid).[3]Another but more specialized method for making aryl–NO2 group starts from halogenated phenols, is theZinke nitration.
Bydecarboxylation ofα-nitrocarboxylic acids (a variant of theKrapcho decarboxylation). The latter can be formed viaα-nitration, e.g. betweennitriles andethyl nitrate;[12][13] or a Meyer-type reaction with a halocarboxylic acid. For example, nitromethane can be produced in the laboratory by treatingsodium chloroacetate withsodium nitrite.[14] (In general, alkali nitrites are unsuitable for Meyer reactions, as they give an equilibrium of mostly nitrite esters; but decarboxylation drives the initial equilibrium to the nitro product.)
Despite the occasional use in pharmaceuticals, the nitro group is associated withmutagenicity andgenotoxicity and therefore is often regarded as a liability in thedrug discovery process.[21]
Nitronates are also key intermediates in theNef reaction: when exposed to acids or oxidants, a nitronate hydrolyzes to acarbonyl and (respectively)azanone ornitric acid.[27]
Grignard reagents combine with nitro compounds to give anitrone; but a Grignard reagent with an α hydrogen will then add again to the nitrone to give ahydroxylamine salt.[28]
Manyflavin-dependentenzymes are capable of oxidizing aliphatic nitro compounds to less-toxic aldehydes and ketones.Nitroalkane oxidase and 3-nitropropionate oxidase oxidize aliphatic nitro compounds exclusively, whereas other enzymes such asglucose oxidase have other physiological substrates.[29]
Explosive decomposition of organo nitro compounds are redox reactions, wherein both the oxidant (nitro group) and the fuel (hydrocarbon substituent) are bound within the same molecule. The explosion process generates heat by forming highly stable products including molecularnitrogen (N2), carbon dioxide, and water. The explosive power of this redox reaction is enhanced because these stable products are gases at mild temperatures. Manycontact explosives contain the nitro group.
^Henry Feuer, ed. (1970).Nitro and Nitroso Groups: Part 2, Volume 2. PATAI'S Chemistry of Functional Groups. Vol. 2. John Wiley & Sons Ltd.doi:10.1002/9780470771174.ISBN978-0-470-77117-4.Saul Patai, ed. (1982).Nitro and Nitroso Groups: Supplement F: Part 2, Volume 2. PATAI'S Chemistry of Functional Groups. John Wiley & Sons Ltd.doi:10.1002/9780470771679.ISBN978-0-470-77167-9.Saul Patai, ed. (1982).Amino, Nitroso and Nitro Compounds and Their Derivatives: Supplement F: Part 1, Volume 1. PATAI'S Chemistry of Functional Groups. John Wiley & Sons Ltd.doi:10.1002/9780470771662.ISBN978-0-470-77166-2.
^Olga V. Dorofeeva; Yuriy V. Vishnevskiy; Natalja Vogt; Jürgen Vogt; Lyudmila V. Khristenko; Sergey V. Krasnoshchekov; Igor F. Shishkov; István Hargittai; Lev V. Vilkov (2007). "Molecular Structure and Conformation of Nitrobenzene Reinvestigated by Combined Analysis of Gas-Phase Electron Diffraction, Rotational Constants, and Theoretical Calculations".Structural Chemistry.18 (6):739–753.doi:10.1007/s11224-007-9186-6.S2CID98746905.
^Olah, George A.; Ramaiah, Pichika; Chang-Soo, Lee; Prakash, Surya (1992). "Convenient Oxidation of Oximes to Nitro Compounds with Sodium Perborate in Glacial Acetic Acid".Synlett.1992 (4):337–339.doi:10.1055/s-1992-22006.
^Ehud, Keinan; Yehuda, Mazur (1977). "Dry ozonation of amines. Conversion of primary amines to nitro compounds".The Journal of Organic Chemistry.42 (5):844–847.doi:10.1021/jo00425a017.
^Weygand, Conrad (1972). Hilgetag, G.; Martini, A. (eds.).Weygand/Hilgetag Preparative Organic Chemistry (4th ed.). New York: John Wiley & Sons, Inc. p. 1007.ISBN978-0-471-93749-4.
^Whitmore, F. C.; Whitmore, Marion G. (1923). "Nitromethane".Organic Syntheses.1: 401.doi:10.15227/orgsyn.003.0083.
^Hawthorne, M. Frederick (1956). "Aci-Nitroalkanes. I. The Mechanism of the ter Meer Reaction1".Journal of the American Chemical Society.78 (19):4980–4984.doi:10.1021/ja01600a048.
^3-Hexene, 3,4-dinitro- D. E. Bisgrove, J. F. Brown, Jr., and L. B. Clapp.Organic Syntheses, Coll. Vol. 4, p. 372 (1963); Vol. 37, p. 23 (1957). (Article)
^Zocher, Georg; Winkler, Robert; Hertweck, Christian; Schulz, Georg E (2007). "Structure and Action of the N-oxygenase AurF from Streptomyces thioluteus".Journal of Molecular Biology.373 (1):65–74.doi:10.1016/j.jmb.2007.06.014.PMID17765264.
^Bordwell, Frederick G; Satish, A. V (1994). "Is Resonance Important in Determining the Acidities of Weak Acids or the Homolytic Bond Dissociation Enthalpies (BDEs) of Their Acidic H-A Bonds?".Journal of the American Chemical Society.116 (20): 8885.doi:10.1021/ja00099a004.
^Ranganathan, Darshan; Rao, Bhushan; Ranganathan, Subramania; Mehrotra, Ashok & Iyengar, Radha (1980). "Nitroethylene: a stable, clean, and reactive agent for organic synthesis".The Journal of Organic Chemistry.45 (7):1185–1189.doi:10.1021/jo01295a003.
^Jubert, Carole & Knochel, Paul (1992). "Preparation of polyfunctional nitro olefins and nitroalkanes using the copper-zinc reagents RCu(CN)ZnI".The Journal of Organic Chemistry.57 (20):5431–5438.doi:10.1021/jo00046a027.
^Bartoli, Giuseppe; Marcantoni, Enrico; Petrini, Marino (1992) [14 Apr 1992]. "Nitrones from addition of benzyl and allyl Grignard reagents to alkyl nitro compounds: chemo-, regio-, and stereoselectivity of the reaction".Journal of Organic Chemistry.57 (22). American Chemical Society:5834–5840.doi:10.1021/jo00048a012.
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