Electrophilic aromatic substitution. Part 29. The kinetics and products of the solvolyses in aqueous sulphuric acids of 2-cyano-3,4-dimethyl-4-nitrocyclohexa-2,5-dienyl acetate: the non-occurrence of an intramolecular 1,3-migration of the nitro-group in the solvolytic reactions of the diene. The kinetics and products of nitration of 2,3-and 3,4-dimethylbenzonitrile

1983 ◽  
pp. 1003 ◽  
Author(s):  
Colin Bloomfield ◽  
Roy B. Moodie ◽  
Kenneth Schofield
Keyword(s):  
Nitro Group ◽  
Electrophilic Aromatic Substitution ◽  
Aromatic Substitution

scholarly journals Nitropyridines: Synthesis and reactions

2003 ◽  
Vol 75 (10) ◽  
pp. 1403-1415 ◽  
Author(s):  
J. M. Bakke
Keyword(s):  
Reaction Mechanism ◽  
Organic Solvent ◽  
Nitro Group ◽  
Sulfonic Acid ◽  
Electrophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Method ◽  
Sigmatropic Shift ◽  
Oxidative Substitution ◽  
Substituted Pyridines

Reaction of pyridine and substituted pyridines with N2O5 in an organic solvent gives the N-nitropyridinium ion. When this is reacted with SO2/HSO3– in water, 3-nitropyridine is obtained (77 % yield). With substituted pyridines, the method gives good yields for 4-substituted and moderate yields for 3-substituted pyridines. The reaction mechanism is not an electrophilic aromatic substitution, but one in which the nitro group migrates from the 1-position to the 3-position by a [1,5 ] sigmatropic shift. From 4-aminopyridine, imi- dazo [4,5-c ] pyridines have been synthesized. From 3-nitropyridine, 5-nitropyridine-2-sulfonic acid is formed in a two-step reaction. From this, a series of 2-substituted-5-nitro-pyridines has been synthesized. 3-Nitropyridine and 4-substituted-3-nitropyridines have been substituted with ammonia and amines by the vicarious substitution method and by the oxidative substitution method in the position para to the nitro group. High regioselectivities and yields have been obtained in both cases to afford a series of 4-substituted-2-alkylamino-5-nitropyridines.

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