2-Picoline nitration

Nitraminopicolines, HsC(CsN)H3(NH-NOa), mw 153.14, N 27.44%. The following isomers are described in the literature orNitramino-fi-picoline or 3-/Vriro 3-me/Ay/-Pyridine. Lt yel ndls, mp 159° with decompn. Was prepd by nitrating 2-am ino-3-methyl-pyridine with HN03(d 1.4) in coned HaS04 in the cold... 

Chlorination and bromination of pyridine and some alkylpyridines in the (3-position can be effected in the liquid phase at 100°C using excess AlCl3as catalyst. -Bromination of pyridine and 2- and 4-picoline is conveniently effected in oleum at 80-120°C. Bromination kinetics using HOBr in aqueous HC104 indicate that the partial rate factor for bromination of the pyridinium cation is 10 13, comparable to that for nitration. 

Alkylpyridines (picolines, and especially lutidines) can be nitrated much more readily, as Plazek [75] has shown. Introduction of the nitro group is greatly facilitated by the presence of the hydroxyl group in the pyridine ring. For example, 3-hydroxypyridine can be nitrated to 2-nitro-3-hydroxypyridine in good yield (Plazek and Rodewald [76]). It may be further nitrated to the dinitro derivative. From this, 3,5-dinitropyridine can be obtained (Plazek [77]). 

N-Halogenation and other oxidative reactions of pyridines and related heterocycles have been re-viewed. ° Thus, pyridines and some diazines can be aminated by mesitylenesulfonylhydroxylamine (32) and similar reagents. / -Nitration of 2-picoline by nitronium tetrafluoroborate gives the salt (46) which is itself a nitrating agent. 

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