反应 #3219

反应方程式

diethyl oxosuccinate sodium salt

8-chloro-2H-3,1-benzoxazine-2,4(1H)-dione

water

→

solid

收率 43.8%

Diethyl 8-chloro-4-hydroxyquinoline-2,3-dicarboxylate

收率 43.8%

溶剂

dimethylformamide

反应条件

后处理

1. 1
   温度maintained at this temperature for 2.5 hr
2. 2
   温度After cooling
3. 3
   萃取the resulting mixture was then extracted with ethyl acetate
4. 4
   洗涤The combined organic extracts were washed with water and brine
5. 5
   干燥dried (MgSO4)
6. 6
   过滤filtered
7. 7
   浓缩concentrated

实验过程

To a stirred mixture of diethyl oxosuccinate sodium salt (2.31 g, 11.0 mM) in dimethylformamide (20 mL) under a nitrogen atmosphere was added 8-chloro-2H-3,1-benzoxazine-2,4(1H)-dione (2.17 g, 11.0 mM). The resulting mixture was heated slowly to 130° C. and maintained at this temperature for 2.5 hr. After cooling, the reaction mixture was poured into water and the resulting mixture was then extracted with ethyl acetate. The combined organic extracts were washed with water and brine, dried (MgSO4), filtered and concentrated to obtain an oily solid (1.55 g). This material was chromatographed (eluant: CH2C12 /CH3OH; 98/2) over silica gel to provide the title compound as an oil which slowly crystallized to a tan solid (0.700 g, 19.7%). A 0.150 g portion of this material was recrystallized from toluene/hexane to provide an analytical sample (0.050 g) of the title compound as a tan solid, mp 98°-99° C.; MS(CI): 324 (M+H).

来源