Imination of<i>N</i>-methylpyridinium salts by liquid ammonia-potassium permanganate. A new synthesis of nudiflorine
作者:D. J. Buurman、H. C. van der Plas
DOI:10.1002/jhet.5570230409
日期:1986.7
Reaction of substituted 1-methyl(benzyl)pyridinium salts (1) with liquid ammonia/potassium permanganate leads to introduction of the imino group at the carbon adjacent to the nitrogen. The regiospecificity of the reaction strongly depends on substituent X: at C-6 for X = H, CONH2, C6H5 and at C-2 for X = CH3. 3-Aminocarbonyl-1-t-butylpyridinium iodide (5) on treatment with liquid ammonia/potassium
取代的1-甲基(苄基)吡啶鎓盐(1)与液态氨/高锰酸钾的反应导致在与氮相邻的碳上引入亚氨基。该反应的区域特异性强烈取决于取代基X:对于C = 6,对于X = H,CONH 2,C 6 H 5,对于C = 2,对于X = CH 3。用液氨/高锰酸钾处理的3-氨基羰基-1-叔丁基碘化碘化物(5)仅得到4-亚氨基化合物8 ; 1 H nmr光谱显示5在液氨中,得到σ-加合物4-氨基-1,4-二氢-和6-氨基-1,6-二氢-3-吡啶甲酰胺的混合物(6和7)。令人惊讶地,在用液态氨/高锰酸钾,1,6-二氢-1-甲基-6-氧代-3-吡啶甲酰胺(14)处理3-氨基羰基-1,6-二甲基吡啶碘化物(13)时观察到了氧十二烷基甲基化反应。被获得。该化合物可以很容易地被三氯氧化磷转化为生物碱nudiflorine(15)。