Synthetic applications of N-N linked heterocycles. Part 7. The preparation of 4-alkyl- and 4-aryl-pyridines by regiospecific attack of Grignard reagents ? to quaternary nitrogen in N-(2,6-dimethyl-4-oxopyridin-1-yl)pyridinium salts
作者:Alan R. Katritzky、Hector Beltrami、Michael P. Sammes
DOI:10.1039/p19800002480
日期:——
N-(2,6-Dimethyl-4-oxopyridin-1-yl)pyridinium salts (4), new reagents for the regiospecific synthesis of 4-substituted pyridines, give moderate to high yields of 4-alkyl- and 4-aryl-pyridines (8)–(10) on reaction with Grignard reagents. The scope and limitations of the reaction, which proceeds via 1,4-dihydro-intermediates (5)–(7), are explored. No 2-substituted pyridines were detected. Some reactions
N-(2,6-二甲基-4-氧杂吡啶-1-基)吡啶鎓盐(4),是用于区域特异性合成4-取代吡啶的新试剂,具有中等至高产率的4-烷基和4-芳基-吡啶(8)–(10)与格氏试剂反应。探索了通过1,4-二氢中间体(5)–(7)进行的反应的范围和局限性。没有检测到2-取代的吡啶。还描述了与有机锂化合物的一些反应。