反应 #1824342

反应方程式

1,4-benzoquinone

isoprene

chromic acid

→

title compound

收率 31.8%

6-methyl-1,4-naphthalene-1,4-dione

收率 31.8%

溶剂

water

acetic acid

acetic acid

water

反应条件

后处理

1. 1
   温度refluxed for 11/2 hours
2. 2
   温度before refluxing for a further 11/2 hours
3. 3
   温度After cooling
4. 4
   萃取extracted with ether (3×50 ml)
5. 5
   洗涤The combined ether fractions were washed with dilute sodium hydroxide solution (2M; 2×50 ml), water (2×50 ml), saturated sodium chloride solution (50 ml)
6. 6
   干燥dried over magnesium sulphate
7. 7
   过滤Filtration and evaporation of solvent under reduced pressure
8. 8
   其他recrystallisation from petroleum ether

实验过程

A solution of 1,4-benzoquinone (13.9 g, 128 mmol) and isoprene (13.1 ml, 131 mmol) was stirred in glacial acetic acid (44 ml) for 68 hours at room temperature. The mixture was diluted with water (44 ml) and refluxed for 11/2 hours. The mixture was cooled to room temperature and acetic acid (84 ml) and chromic acid [chromium trioxide (29.4 g) in water (30 ml)] was added sequentially, before refluxing for a further 11/2 hours. After cooling, the mixture was diluted with water (200 ml) and extracted with ether (3×50 ml). The combined ether fractions were washed with dilute sodium hydroxide solution (2M; 2×50 ml), water (2×50 ml), saturated sodium chloride solution (50 ml) and dried over magnesium sulphate. Filtration and evaporation of solvent under reduced pressure, and repeated recrystallisation from petroleum ether yielded the title compound (7 g).

来源