Bamberger苯并三嗪合成反应

原标题：Bamberger苯并三嗪合成反应

苯胺重氮化后和丙酮酸腙反应得到重氮中间体后，在酸性条件下关环得到苯并三嗪的反应。此反应最早由 Eugen Bamberger在1892年报道。除了丙酮酸腙，苯甲醛苯腙也可以进行此反应。

反应机理

反应实例

【Abramovitch RA, J Chem Soc., 1955, 2326】

1-(4-Ethoxy-3-fluorophenyl)-3,5-diphenylformazan (8). To 2.9 g (0.02 mol) of 4-ethoxy-3-fluoroaniline 5 in 10 mL of 18% HCl acid was added dropwise at 0–5 ℃ a solution of 1.4 g (0.02 mol) of sodium nitrite in 5 mL of water and the mixture was stirred for 1 h at the same temp. This solution was added dropwise with stirring at 0 ℃ to of 3.2 g (0.016 mol) of 7 in 48 mL of pyr and the mixture was stirred for 3 h at 0–10 ℃. The cherry-red precipitate was filtered, washed, dried,and crystallized from EtOH to afford 8 (62%).

6-Ethoxy-7-fluoro-3-phenyl-1,2,4-benzotriazine (9).To formazan 8 (10 mmol) was added 7–10 mL of BF3/AcOH complex. The mixture was heated for 10 min at 100 ℃ (the color changed from violet to

dark-brown), then cooled to 0℃, and poured into ice-cold water (50 mL) to afford 9 on work up and crystallization (EtOH:CHCl3 2:1).

【Noronha G, Expert Opin Drug Dis., 2009, 4, 33】

相关文献

1 Bamberger E Chem Ber 1892 25 3201

2 Abramovitch RA J Chem Soc 1955 2326

3R Abramovitch RA Chem Rev 1964 64 149

4 Katritzky AR Synth Comm 1997 27 3963

5 Khodja M Heteroatom Chem 2006 17 166

6 Aly AA ARKIVOC 2007 xvi 41

7 Noronha G Expert Opin Drug Dis 2009 4 33

编译自：Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 26.