Condensation Reactions of 3-Oxo-2-arylhydrazonopropanals with Active Methylene Reagents: Formation of 2-Hydroxy- and 2-Amino-6-substituted-5-arylazonicotinates and Pyrido[3,2-c]cinnolines via 6π-Electrocyclization Reactions
作者:Saleh M. Al-Mousawi、Morsy A. El-Apasery
DOI:10.3390/molecules17066547
日期:——
(8), depending on the reaction conditions. Similarly, other 3-oxo-3-aryl-2-arylhydrazonopropanals 1a,b condense with active methylene nitriles 2c,d to yield arylazonicotinates 6b,c. In contrast, 2-[(4-nitrophenyl)-hydrazono]-3-oxo-3-phenyl-propanal (1c) reacts with ethyl cyanoacetate to yield ethyl 6-(4-nitrophenyl)-2-oxo-2,6-dihydropyrido[3,2–c]cinnoline-3-carboxylate (11), via a novel 6π-electrocyclization
3-Oxo-3-phenyl-2-(p-tolylhydrazono)propanal (1a) 在乙酸铵存在下与氰基乙酸乙酯在乙酸中缩合生成 2-hydroxy-6-phenyl-5-p-tolylazonicotinic acid乙酯(6a)或2-氨基-6-苯基-5-甲苯基-氮烟酸乙酯(8),取决于反应条件。类似地,其他 3-氧代-3-芳基-2-芳基肼基丙醛 1a,b 与活性亚甲基腈 2c,d 缩合生成芳基氮烟酸酯 6b,c。相反,2-[(4-硝基苯基)-腙]-3-氧代-3-苯基-丙醛 (1c) 与氰基乙酸乙酯反应生成 6-(4-硝基苯基)-2-氧代-2,6- 乙酯二氢吡啶并[3,2-c]cinnoline-3-carboxylate (11),通过一种新的6π-电环化途径。最后,3-oxo-2-(苯肼基)-3-p-tolylpropanal (1d) 与 2a-c 缩合生成哒嗪酮 13a-c。