Synthesis of 4-arylpyridines and substituted β-carbolines via 1,4-Grignard-addition to pyridinecarboxamides
作者:Wolfgang Schlecker、Andreas Huth、Eckhard Ottow、Johann Mulzer
DOI:10.1016/0040-4020(95)00596-z
日期:1995.8
2,5-Pyridinedicarboxamides 1 and 2, 5-bromo-3-pyridinecarboxamide 7 and 3-hydroxy-2,5-pyridinedicarboxamide 9 undergo 1,4-addition with Grignard reagents to give the 2,4,5-or 3,4,5-and 2,3,4,5-substituted pyridines 3–6, 8 and 10 after oxidation with NCS or oxygen. After selective transformation of amides 5 and 8 to carbamates 17 and 19, a modified intramolecular Goldberg amide arylation furnishes the
2,5- Pyridinedicarboxamides 1和2,5-溴-3-吡啶甲酰胺7和3-羟基-2,5-吡啶二甲酰胺9经历1,4-加成与格氏试剂,得到2,4,5-或3,4 NCS或氧气氧化后,可将1,5-和2,3,4,5-取代的吡啶3-6、8和10取代。在将酰胺5和8选择性转化为氨基甲酸酯17和19后,修饰的分子内Goldberg酰胺芳基化反应可提供高收率的β-咔啉22和24。