酸催化下喹恶酮衍生物和N-取代亲核试剂反应得到螺环喹恶酮中间体,重排得到2-杂环取代的苯并咪唑的反应。
反应机理
【Vakhid A.Mamedov, Tetrahedron Letters, Volume 49, Issue 31, 28 July 2008, Pages 4644-464】
反应实例
3-Phenyl-10H-spiro[2-pyrazoline-5,20-quinoxalin]-30(40H)-one (7: R = H, Ar = Ph). 6 (0.23 g, 5 mmol, 90%) in 10 mL n-BuOH and 5 (R = H, Ar = Ph, 0.13 g, 0.5 mmol) were refluxed for 16 h and allowed to stand at r.t. overnight. 7 was filtered, washed with EtOH and crystallized from MeCN to yield 70 mg (51%) of product. Evaporation of the filtrate produced 40 more mg (30%) of 7 (from
MeCN), mp 310–312 C.
2-(5-Phenyl-1H-pyrazol-3-yl)-1H-bezimidazole (8). 7 (200 mg, 0.7 mmol) in 10 mL HOAc was refluxed for 8 h. Evaporation afforded 190 mg of 8, mp 316–317 C.
【Mamedov VA, TetLett., 2009, 50, 5186】
相关文献
1 Taylor EC, McKillop A J Org Chem 1965 30 2858
2 Mamedov VA Bull Russ Acad Sci (Chem) 2004 53 164
3 Mamedov VA Tet Lett 2008 49 4644, 6231
4 Mamedov VA TetLett 2009 50 5186
5 Mamedov VA Bull Russ Acad Sci (Chem) 2010 59 1645
6 Mamedov VA Tet Lett 2010 51 6503
编译自:Organic Syntheses Based On Name Reactions, 3RdEd, A. Hassner, Page 299-300.