Nucleophilic Reaction upon Electron-Deficient Pyridone Derivatives. XIII. Regioselective Synthesis of 2-Substituted 3-Nitropyridines by One-Pot Reaction of Either 4- or 6-Substituted 1-Methyl-3,5-dinitro-2-pyridones with Ketones and Ammonia
A one-pot synthesis of 2-substituted 3-nitropyridines was developed by a ring transformation of 6- or 4-substituted 1-methyl-3,5-dinitro-2-pyridones (2 or 3) with ammonia and enamines derived from ketones. Some intermediates having a 2,6-diazabicyclo[3.3.1]nonane skeleton were isolated from reactions of 3. The ring transformation proceeds via an addition-addition-elimination-elimination mechanism.
A Microwave-Assisted Facile One-Pot Synthesis of Annelated Pyridines from β-Formyl Enamides via Henry Reaction
作者:Romesh C. Boruah、Apurba Chetia、Moanochet Longchar、Kushal C. Lekhok
DOI:10.1055/s-2004-825595
日期:——
The base-catalysed solid phase condensation of β-formyl enamides with nitromethane under microwave irradiation afforded a novel one-pot synthesis of pyridines via Henry reaction.
Regioslective Synthesis of 2-Substituted 3-Nitropyridines by One-Pot Reaction of Either 4- or 6-Substituted 1-Methyl-3,5-dinitro-2-pyridones with Ketones and Ammonia
作者:Yasuo Tohda、Tooru Kawara、Miyuki Eiraku、Keita Tani、Masahiro Ariga、Yutaka Mori
DOI:10.3987/com-91-5832
日期:——
Regioselective synthesis of 2-substituted 3-nitropyridines was achieved by one-pot reaction of either 4- or 6-substituted 1-methyl-3,5-dinitro-2-pyridones with ketones in the presence of ammonia. The selectivity is interpreted in terms of steric factor of substituent on the pyridone.