Pyridine 4-nitro

The reaction of anilines (R = H, m- and p-CHg, m- and p-halo-geno, m-N02, p-OCHg, P-OC2H6) with 2-chloro-3-nitro-, 2-chloro-5-nitro-, 2-chloro-3-cyano-6-nitro-, 2-chloro-3-cyano-6-methyl-5-nitro-, and 2-chloro-3-cyano-4,6-dimethyl-6-nitro-pyridines. ... 

Reagent P-K a 2-Chloro- pyrimidine 2-Chloro- 3-nitro- pyridine 2-Chloro- 5-nitro- pyridine 2,4-Dichloro- phenylamino-s-triazine ... 

Auch Nitro-pyridine werden mit guten Ausbeuten zu Amino-pyridinen reduziert z.B. ... 

Nitroenamines and related compounds have been used for synthesis of a variety of heterocyclic compounds. Rajappahas summarized the chemistry of nitroenamines (see Section 4.2).140 Ariga and coworkers have developed the synthesis of heterocycles based on the reaction of nitropyridones or nitropyrimidinone with nucleophiles. For example, 2-substituted 3-nitro-pyridines are obtained by the reaction of l-methyl-3,5-dinitro-2-pyridones with ketones in the presence of ammonia (Eq. 10.82).141... 

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... 

Ira Falle des 3,5-Dimethyl-4-nitro-pyridins wird anstelle des Azo-Produktcs das Tetrahydropyridin gebildct. Die Nitro-Gruppe bleibt unverandcrt, dies ist auch der Fall mit Natriumboranat. 4-Nitro-pyridin wird von Natriumboranat in 54% Ausbeute zur Azo-Verbindung reduziert1. 

Nitro-arene allgemeine Arbcitsvorschrift5 Zu 5-10 ml Aren werden aquivalente Mengen (0,1-0,5 g) Metall(IV)-nitrat [beim Titan(l V)-nitrat werden 25 ml einer 0,1 M Losung eingesetzt] bei 20° unter Ruhren addiert. Obwohl die Reaklion nach 1 min beendet ist, fiihrt man die quantitative GLC erst nach 30 min durch. Fiir Nitro-pyridine bzw. Nitro-chinoline wild cine Polyethylen-glykol-Saule bei 150° hzw. eine Silicon SE30-Saule bei 140° verwendet. 

Aminopyridine has been prepared by heating nicotinamide in an alkaline potassium hypobromite solution at 70° by hydrolysis of 8-pyridylurethan with oleum by heating 3-amino-pyridine-2-carboxylic acid at 250° by reduction of 3-nitro-pyridine with zinc and hydrochloric acid and by heating 3-bromopyridine with ammonia and copper sulfate in a sealed tube. ... 

A compound (40), isolated from the reaction between 2-chloro-5-nitro-pyridine and tert-butyl jV-hydroxycarbamate, has been shown to react with benzaldehyde to give 6-nitro-2-phenyl-triazolopyridine (41)53 5-nitro-2-pyridone acts as a leaving group. 

Method B Protected Cys(Npys) di-K2K core 39 (4 mg, 8 pmol)1441 was suspended in 0.05 M AcOH (5 mL) and the pH of the mixture adjusted to 8 with 1M NH4OH, and DTT (8 mg) was added. The reaction was spurred by N2 and stirred for 0.5 h. The dark yellow soln was applied to a short Sephadex G10 column and eluted with 0.05 M AcOH. The first eluting fractions, positive by Ellman s test and containing the SH functionalized core, were pooled and Cys(Npys) activated peptide (8.8 pmol, 26 mg) was added. The pH was adjusted to 6 with 1M NaOH. The mixture was purged with N2 and stirred overnight. The liberated 3-nitro-pyridine-2(l//)-thione was eliminated by rapid gel filtration. The MAP was then purified to give 62b by HPLC to eliminate the excess peptide monomer yield 12 mg. 

Nitropyridine 166 in the Barton-Zard condensation behaves specifically affording tricyclic compound 167 (00SL213). Evidently, 4-azaisoindole derivative 168 formed in the first step reacts further with another molecule of nucleophile that results in imidazole ring closure (Scheme 50). Under the same conditions 4-nitro-pyridine remains unchanged. 

NPO 4-nitro pyridine-N-oxide HIPT /3-isopropyl tropolone... 

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. 

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