3-氧代-2-芳腙基丙醛与活性亚甲基试剂的缩合反应：通过 6π-电环化反应形成 2-羟基和 2-氨基-6-取代-5-芳基偶氮烟酸和吡啶并[3,2-c]肉桂啶。

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.

机构信息

Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait.

出版信息

Molecules. 2012 May 30;17(6):6547-56. doi: 10.3390/molecules17066547.

3-Oxo-3-phenyl-2-(p-tolylhydrazono)propanal (1a) undergoes condensation with ethyl cyanoacetate in acetic acid in the presence of ammonium acetate to yield either 2-hydroxy-6-phenyl-5-p-tolylazonicotinic acid ethyl ester (6a) or 2-amino-6-phenyl-5-ptolyl-azonicotinic acid ethyl ester (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 pathway. Finally, 3-oxo-2-(phenylhydrazono)-3-p-tolylpropanal (1d) condenses with 2a-c to yield pyridazinones 13a-c.

3-氧代-3-苯基-2-(对甲苯基腙基)丙醛（1a）在乙酸存在下与氰基乙酸乙酯缩合，并根据反应条件，生成 2-羟基-6-苯基-5-对甲苯基偶氮烟酸乙酯（6a）或 2-氨基-6-苯基-5-对甲苯基偶氮烟酸乙酯（8）。同样，其他 3-氧代-3-芳基-2-芳基腙基丙醛 1a,b 与活性亚甲基腈 2c,d 缩合，生成芳基偶氮烟酸酯 6b,c。相比之下，2-[(4-硝基苯基)腙基]-3-氧代-3-苯基丙醛（1c）与氰基乙酸乙酯反应，通过新颖的 6π-电环化途径，生成乙酯 6-(4-硝基苯基)-2-氧代-2,6-二氢吡啶并[3,2-c]肉桂酸酯（11）。最后，3-氧代-2-(苯基腙基)-3-对甲苯基丙醛（1d）与 2a-c 缩合，生成哒嗪酮 13a-c。