Diversity of Reactions of Isomeric Aminopyridine<i>N</i>-Oxides with Chloronitropyridines: An Experimental and Theoretical Study
作者:Ewa Wolińska、Wiesław Pucko
DOI:10.1002/jhet.1536
日期:2013.5
Reaction of 2‐aminopyridine N‐oxides 1a, 1b, 1c, 1d with chloronitropyridine 7a gave 2‐[(pyridin‐2‐yl)amino]pyridine N‐oxides 8a, 8b, 8c and 9 in good yield. The reactions of 4‐ and 3‐aminopyridine N‐oxides 12a,12b and 24 with 7a, 7b, 7c proceed in the different manner involving initial formation of the intermediary 1‐pyridyloxypyridinium salts 13a, 13b, 13c, 13d and 26, which rearrange to 4‐[(5‐n
2-氨基吡啶N-氧化物1a,1b,1c,1d与氯硝基吡啶7a的反应产生了2-[(吡啶-2-基)氨基]吡啶N-氧化物8a,8b,8c和9,收率很高。4氨基和3氨基吡啶N-氧化物12a,12b和24与7a,7b,7c的反应以不同的方式进行,涉及初始形成中间的1-吡啶氧基氧吡啶鎓盐13a,13b,13c,13d和26,它们重新排列为4-[((5-硝基吡啶-2-基)氨基]吡啶N-氧化物22和1-(3-氨基吡啶-2-基)吡啶-2-一衍生物27a,图27b。但是,经N保护的2-氨基吡啶N-氧化物17生成季铵盐1-吡啶氧基吡啶鎓盐18a,18b,在用氨水处理后,得到2-[((吡啶-2-基)氨基)氨基]吡啶N氧化物8a和20。。进行了DFT / B3LYP / 6-311 ++ G(d,p)级的量子化学计算,以解释在异构氨基吡啶N-氧化物中额叶轨道的性质和原子电荷分布的差异。