79899-29-9Relevant articles and documents
Selective vicarious nucleophilic amination of 3-nitropyridines
Bakke, Jan M.,Svensen, Harald,Trevisan, Raffaela
, p. 376 - 378 (2007/10/03)
Nine 3-nitropyridine compounds and 4-nitroisoquinoline have been aminated in the 6-position (for 4-nitroisoquinoline in the 1-position) by vicarious nucleophilic substitution reactions. Two amination reagents were used, hydroxylamine and 4-amino-1,2,4-triazole. The yields were from moderate to good. Use of hydroxylamine gave an easy work-up procedure by which almost pure product was obtained directly, but 4-amino-1,2,4-triazole gave better yields of the aminated product for some of the substrates. By this, a general method for the preparation of 3- or 4-substituted-2-amino-5-nitropyridines was obtained.
Ring Transformations in Reactions of Heterocyclic Compounds with Nucleophiles. Conversion of 5-Nitropyrimidine into 2-Substituted 5-Nitropyrimidine and 2-Amino-5-nitropyridines by Amidines
Barczynski, P.,Plas, H. C. van der
, p. 1077 - 1080 (2007/10/02)
The reaction of 5-nitropyrimidine (1) with benzamidine, pivalamidine, acetamidine, propionamidine, α-phenylacetamidine, O-methylisourea hydrochlorides, and cyanamide in ethanolic solution in the presence of triethylamine has been investigated.It was found that reaction of 1 with alkyl(aryl) amidines, having no active methylene groups attached to the amidine moiety (pivalamidine, benzamidine), exclusively formed the corresponding 2-substituted 5-nitropyrimidines in good yields.With acetamidine and propionamidine, in addition to the formation of the 2-substituted 5-nitropyrimidines, the formation of 2-amino-5-nitropyridines also was observed; with α-phenylacetamidine a 2-amino-5-nitropyridine derivative exclusively was obtained.The reaction of 1 with both O-methylisourea and cyanamide leads to 2-amino-5-nitropyrimidine.These reactions provide new examples of degenerate ring transformations of the pyrimidine ring system and of the ring transformation of pyrimidines into pyridines.
