Cyclocondensation of α-oxoketene dithioacetals with β-lithioamino-β- substituted acrylonitriles:synthesis of 2,6-substituted and 5,6-annelated 3-cyano-4- (methylthio) pyridines
作者:Arun K. Gupta、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1016/s0040-4020(01)81540-4
日期:1990.1
The lithiated β-amino-β-substituted acrylonitriles 4a-d generated in situ by reaction of lithioacetonitrile with either acetonitrile or substituted nitriles undergo cyclocondensation with α-oxoketenedithioacetals through 1,4-addition to afford 2,6-substituted and 5,6-annelated-4-(methylthio)-3-cyanopyridines 6a-m, 11a-h and 12a-b in good yields. A few of the 2,6-diheterylpyridines 6n-q were also synthesized
通过硫代乙腈与乙腈或取代的腈反应原位生成的锂化的β-氨基-β-取代的丙烯腈4a-d通过1,4-加成与α-氧杂环丁二硫缩醛进行环缩合,得到2,6-取代的和5,6-使4-(甲硫基)-3-氰基吡啶6a-m,11a-h和12a-b退火。按照该方法,还合成了一些2,6-二杂基吡啶6n-q。另一方面,将相应的α-肉桂酰基12a-c和α-(5-芳基-2,4-戊二烯酰基)(12d)酮二硫缩醛与4a环合,得到相应的4-芳基-(或4-苯乙烯基-6- [2-双(甲硫基)乙烯基] -3-氰基吡啶14a-d具有良好的产率。