3- Amino-5-nitropyridine

Reaction of nitroketene animals with enaminoketones provides a route for the derivatives of 2-amino-3-nitropyridines (Eq. 10.87).147... 

Methods of preparation of 2,3-diaminopyridine which involve the reduction of 2-amino-3-nitropyridine are laborious. The material is obtained in yields of less than 10% by nitration of... 

Diaminopyridine has been prepared by reduction of 2-amino-3-nitropyridine with iron and aqueous acidified ethanol,3 tin and hydrochloric acid,6 or stannous chloride and hydrochloric acid,6 by catalytic reduction of 3-amino-2-nitropyridine,6 by reduction of 3-amino-2-nitropyridine,7 2-amino-5-chloro-3-nitro-pyridine,8 or 2-amino-5-bromo-3-nitropyridine 4 with sodium hydroxide solution and an aluminum nickel alloy, and by catalytic reduction of 2-amino-5-bromo-3-nitropyridine.4 Animation of... 

Ingalls and Popp98 reacted 2-aminopyridines with diethyl malonate at 200°C. 2-Amino-3-nitropyridine failed to react, but in contrast to the findings... 

Methylamination of 2-amino-3-nitropyridine gives in good yield 2-amino-6-methylamino-3-nitropyridine, while methylamination of 6-amino-3-nitro-pyridine only gives (in a small yield) 6-amino-2-methylamino-3-nitropyr-idine (Scheme 7). The activating influence of the 3-nitro group on the C-6 para position explains this difference in reactivity. 

Three of the four polymorphic compounds examined in this study [107] readily form co-crystals e.g. 2-hexeneoic acid isonicotinamide, 2-amino-5-nitropyrimi-dine 2-amino-3-nitropyridine, and 3-dimethylaminobenzoic acid 4-chlorobenza-mide. The structural behavior of 1-3 supports the suggestion that polymorphs make good co-crystallizing agents (provided that solubility differences are not too large). However, no co-crystals with maleic hydrazide were obtained, despite the fact that it exists in three different polymorphs. 

When a solution of 2-aminopyridine is treated with bromine, 2-amino-5-bromopyridine is obtained. Bromination of 2-amino-3-nitropyridine and 2-amino-5-nitropyridine gives 2-amino-5-bromo-3-nitropyridine and 2-amino-3-bromo-5 -nitropy ridine, respectively. ... 

Examples of cocrystals containing chains, ribbons, and other infinite ID motifs (Scheme 8) include bipyridine dihydroxybenzene, melamine cyanuric acid, bipyridine (fluorinated)dibromobenzene, 2-aminopyridine dicar-boxylic acids, triaminopyrimidine barbituric acid, 2-aminopyrimidine dicarboxylic acid, " 1,2,3-trihydroxy-benzeneihexamethylenetetramine, diols diamines, bis-benzimidazole dicarboxylic acids, and 2-amino-5-nitro-pyrimidine 2-amino-3-nitropyridine." ... 

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