1- Nitropropane, nitronate anion from

It has been proposed that 8-aminodcoxyguanosinc is formed from the nitronate tautomer of 2-nitropropane either by base nitrosation followed by reduction, or via an enzyme-mediated conversion of the nitronate anion to hydroxyiam ine-O-sulfonate or acetate, which yields the highly reactive nitrenium ion NHj (Sodum et al., 1993). Sodum et al. (1994) have provided evidence for the activation of 2-nitropropane to an aminating species by rat liver aryl sulfotransferase in vitro and in vivo. Pretreatment of rats with the aryl sulfotransferase inhibitors pentachlorophenol or 2,6-dichloro-4-nitrophenol significantly decreased the levels of nucleic acid modifications produced in the liver by 2-nitropropane treatment. Partially purified rat liver aryl sulfotransferase activated 2-nitropropane and its nitronate at neutral pH to a reactive species that aminated guanosine at the position. This activation was dependent on the presence of the enzyme, its specific cofactor adenosine 3 -phosphate 5 -phosphosulfate, and mercaptoethanol. It was inhibited... 

More recently the C-alkylation of 15 by 2-nitropropane anion was extended to the heterocycle nitronate anion derived from l-methyl-3-nitropyrrolidin-2-one93. 

The anions of nitroalkanes (nitronates) can be used as precursors in a connective and regiospecific synthesis of tetrasubstituted alkenes. They are easily formed on reaction with LiOMe and undergo oxidative dimerization in the presence of bromine. The resultant 1,2-dinitroalkanes (Scheme 37) participate in a reductive elimination involving an rc1 radical chain mechanism when irradiated in the presence of Na2S, PhSNa or the lithium nitronate derived from 2-nitropropane. 

The tautomeric nitronic acids of secondary nitroalkanes or their nitronate salts react with nitrous acid or alkali metal nitrites to yield pseudonitroles.These pseudonitroles are often isolated as their colourless dimers (78b) but are deep blue in monomeric form (78a). Primary nitroalkanes also form pseudonitroles (80b) but these rapidly isomerise to the nitrolic acid (80a).Reactions are commonly conducted by slowly acidifying a mixture containing the nitronate salt and the metal nitrite, during which, the nitronic acid reacts with the nitrite anion. These reactions, first discovered by Meyer, have been used to prepare 2-nitroso-2-nitropropane (78a) and acetonitrolic acid (80a) from 2-nitropropane (76) and nitroethane (22) respectively. ... 

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],... 

Nitroalkanes are acidic compounds the dissociation of a proton from a nitroalkane produces the nitroalkane anion, or nitronate, whose chemical and physical properties differ from those of the parent nitroalkane. The nitronate form of 2-nitropropane is more mutagenic in S. typhimurium TAIOO and TA 102 than is the neutral parent compound (Fiala et al., 1987b Dayal et al., 1989 Kohl et al., 1994), suggesting that propane 2-nitronate may act as an intennediate in the mechanism by w hich 2-nitropropane exerts its genotoxic and carcinogenic effects. This hypothesis is supported by studies indicating that both bacterial mutagenicity and induction of unscheduled DNA synthesis in rat hepatocytes are decreased by conditions (low pH or deuteration of the secondary carbon atom) that limit formation of the nitronate tautomer, and that the tautomerization of 2-nitropropane can be influenced by hepatic enzymes (Kohl et al., 1994). 

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