Reactions of Methyl Ketones and (Hetero)arylcarboxamides with N,N-Dimethylacetamide Dimethyl Acetal. A Simple Metal-Free Synthesis of 2,4,6-Trisubstituted Pyridines
作者:Benjamin Prek、Uroš Grošelj、Marta Kasunič、Silvo Zupančič、Jurij Svete、Branko Stanovnik
DOI:10.1071/ch14349
日期:——
Two metal-free syntheses of 2,4,6-trisubstituted pyridines 10a–m and 16a–j are described. N,N,6-Trimethyl-4-(substituted)pyridin-2-amines 10 were prepared from aryl or heteroaryl methyl ketones which were transformed with N,N-dimethylacetamide dimethyl acetal (DMADMA) into enaminones 4a–m, followed by treatment with ammonium acetate to give (Z)-3-amino-1-(substituted)but-2-en-1-ones 5a–m. These were
描述了2,4,6-三取代的吡啶10a - m和16a - j的两种无金属合成方法。由芳基或杂芳基甲基酮制备N,N,6-,三甲基-4-(取代)吡啶-2-胺10,然后用N,N-二甲基乙酰胺二甲基乙缩醛(DMADMA)转化为烯胺4a – m,然后进行处理用乙酸铵得到(Z)-3-氨基-1-(取代的)丁-2-烯-1-酮5a – m。这些与DMADMA微波辐射下在130℃的密闭容器中进行处理,经由中间体,得到7 - 9最终产物10A -米。N 2,N 2,N 4,N 4-四甲基-6-(取代的)吡啶-2,4-二胺16a – j由一锅法合成,由相应的羧酰胺11a – j通过过量的二甲酰胺处理而制得。 DMADMA在密闭容器中在微波辐射下通过中间体12a – j至15a给出– j最终产品16a – j。烯胺酮5c,5g,5i,5j和5m以及2,4,6-三取代吡啶16a,16b,16g,16i和16j的X射线单晶衍射研究与预期结构一致。