2-Bromo-3,5-dinitropyridine

Treatment of 2-bromo-3,5-dinitropyridine with hydrogen bromide and granulated tin gives 3,5-diaminopyridine. ... 

Kinetic studies have been reported of the reactions of a series of 2-substituted-5-nitrothiophenes (substituent = Br, OMe, OPh, OC6H4-4-NO2) with secondary amines in room-temperature ionic liquids. The kinetic behaviour is similar to that of the corresponding reactions in methanol so that most reactions do not show base catalysis. The observation that reactivity is higher in the ionic liquids than in methanol (or benzene) is attributed to relatively poor solvation of the reagents by the ionic liquids. As in conventional solvents, 2-bromo-3-nitrothiophene shows higher reactivity than 2-bromo-5-nitrothiophene.42 Solvent effects on the kinetics of the alkaline hydrolysis of 2-phenylthio-3,5-dinitropyridine in aqueous organic solvents have been analysed.43... 

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). 

Since these early studies, numerous derivatives of 2-chloro- and 2-bromo ia, 672 and 4-chloro- and 4-bromo-pyridine 73 have been converted into amino- or alkylamino-pyridines under conditions differing little from those mentioned above. Modifications which have been used include the addition of copper sulphate as a catalyst a, 672a reaction in the presence of pyridine 64 and also, in the case of 4-chloropyridine, reaction with primary and secondary aliphatic amines in benzene 4 at 140-180 . The qualitative data from these numerous examples show the effect of other substituents upon 2- and 4-halogen atoms to be as expected. GarboxyM oa, 675, 9i8 and nitro-groups24ia markedly augment reactivity, and in a compound such as 2-chloro-3,5-dinitropyridine, much milder conditions than usual can be used for amination e ... 

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