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6- Amino-3-nitropyridine, formation

All these amination reactions show exclusive SNH substitution. There is hardly any indication for the formation of 3-nitropyridines, in which the chloro or methoxy group was replaced by an amino group, even when these leaving groups are present at the reactive a-position of the pyridine ring. It seems to be a characteristic feature of the oxidative amination... [Pg.6]

Nitration of pyridines via rearrangement of nitramines has been studied. 4-Amino-3-bromopyridine forms, with nitric acid, the nitramine 9.67 in 85% yield 9.67 rearranges in sulfuric acid to 4-amino-3-bromo-5-nitro-pyridine (9.68) in 97% yield (62RC967). The rearrangement of 2-nitrami-no-4-nitropyridine (9.69) to 2-amino-3,4-dinitropyridine is accompanied by the formation of 4-nitro-2-pyridone (64T81), subsequently shown to arise via nitrosation (79T2895). [Pg.296]

Nitro compounds are easily reduced, catalytically or chemically, to amino compounds. Incomplete reduction can lead to a hydroxylamino derivative or to binuclear azo, azoxy, and hydrazo compouds, e.g., 789 790, 791. Examples include reduction of 3-nitropyridines using aqueous sodium hydrosulfite at room temperature <2005JME5104> and of 2-nitropyridine by transfer hydrogenation in the presence of 10% Pd/G and recyclable polymer-supported formate, prepared from aminomethylpolystyrene resin and ammonium formate <2005SC223>. A nitro group can be reduced in the presence of an A-oxidc group, e.g., 784 782. [Pg.350]

Halo-4-nitropyridines and their A -oxides react at the C-nitro group when treated with bases or alkoxides to give XII-357 or MI-358 (X = Cl, Br, I). However, 3-fluoro-4-nitropyTidine and its 1-oxide form 4-nitro-3-pyridinols and 4-nitro-3-alkoxypyridines, respectivelyThe 3-alkoxy-4-nitropyridine-l-oxides have been converted to 3,4-dialkoxypyridine-l-oxides. Because of this marked reactivity of the 3-fluoro substituent, these studies have been extended to 3-fluoro-5-methyl-4-nitropyridine-l-oxide, 3-fluoro-2-methyl-4-nitropyri-dine-l-oxide, and 2,6-dimethyl-3-fluoro-4-nitropyridine-l-oxide. Several of these fluoronitropyridines have been extensively studied as potential reagents for formation of amino acid derivatives. 2-Fluoro-3,5-dinitropyridine, a typical example, is hydrolyzed by hot water and reacts with hot alcohols to form 2-alkoxy-3,5-dinitropyridines and reacts with amino acids and their derivatives to give well-defined products. The reactions of a number of fluoronitropyridines and their N-oxides have been summarized by Talik and Talik and the relative reactivities toward simple nucleophiles have been observed, as shown on p. 689. [Pg.688]

The directing and activating power of the amino group shows clearly in 2-dimethylaminopyridine, where nitramine formation is impossible. Nitration in mixed acids gives about 90 per cent of 2-dimethylamino-5- and 10 per cent of 2-dimethylamino-3-nitropyridine. 3,5-Dinitration is readily... [Pg.173]


See other pages where 6- Amino-3-nitropyridine, formation is mentioned: [Pg.43]    [Pg.235]    [Pg.16]    [Pg.59]    [Pg.142]    [Pg.54]    [Pg.192]    [Pg.306]    [Pg.520]    [Pg.64]    [Pg.520]    [Pg.210]    [Pg.54]    [Pg.192]    [Pg.405]    [Pg.170]    [Pg.297]    [Pg.194]    [Pg.72]    [Pg.145]    [Pg.49]    [Pg.172]    [Pg.384]    [Pg.252]    [Pg.217]   
See also in sourсe #XX -- [ Pg.7 ]




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2- Amino-3-nitropyridine

2-Amino-3-nitropyridines, formation

2-Amino-3-nitropyridines, formation

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