Synthetic applications of N–N linked heterocycles. Part 9. Preparation of α-(4-pyridyl)nitroalkanes and N-(4-pyridyl)azoles by regiospecific attack of nitroalkyl and azolyl anions on N-(2,6-dimethyl-4-oxopyridin-1-yl)pyridinium salts
作者:Alan R. Katritzky、James G. Keay、David N. Rogers、Michael P. Sammes、Christopher W. F. Leung
DOI:10.1039/p19810000588
日期:——
Sodium salts of nitroalkanes and of azoles react with N-(2,6-dimethyl-4-oxopyridin-1-yl)pyridinium salts (1)–(3) to give regiospecifically 1,4-dihydropyridines (12)–(14), (15), and (16) in high yields. Photolysis of the dihydropyridines gives α-(4-pyridyl)nitroalkanes (7)–(9) and N-(4-pyridyl)azoles in moderate to good yields. Certain azolyl dihydropyridines revert to the parent azole on photolysis;
硝基烷烃和吡咯的钠盐与N-(2,6-二甲基-4-氧杂吡啶-1-基)吡啶鎓盐(1)–(3)反应生成区域特异性的1,4-二氢吡啶(12)–(14) ,(15)和(16)高产。二氢吡啶的光解作用可以中等至良好的产率得到α-(4-吡啶基)硝基烷烃(7)-(9)和N-(4-吡啶基)唑。某些偶氮基二氢吡啶在光解时会还原为母体吡咯;这似乎是位阻效应。