反応 #715412

反応方程式

Benzo[1,2-b:4,5-b′]dithiophene-4,8-dione

dimethyl sulfate

NaBH4

diethyl ether

potassium hydroxide

→

solid

収率 62.0%

4,8-Dimethoxy-benzo[1,2-b:4,5-b′]dithiophene

収率 62.0%

溶媒

water

ethanol

water

water

反応条件

後処理

1. 1
   その他fitted with a reflux condenser
2. 2
   温度The reaction mixture was heated
3. 3
   温度to reflux for 1 hour
4. 4
   workup.ADDITIONwas added slowly to the reaction mixture with vigorous stirring
5. 5
   温度at reflux for 30 minutes
6. 6
   温度the suspension was refluxed for 64 hours
7. 7
   洗浄The organic layer was washed with brine (200 mL)
8. 8
   乾燥dried with MgSO4
9. 9
   濃縮concentrated
10. 10
    その他The crude material was purified by silica gel column chromatography (solid loading, gradient of 1:1 to 1:2 hexanes-dichloromethane)

実験手順

Benzo[1,2-b:4,5-b′]dithiophene-4,8-dione (7.50 g, 34.0 mmol., 1.00 equiv.), ethanol (45 mL) and water (45 mL) were added to a 250 mL 2-neck round-bottom flask fitted with a reflux condenser. NaBH4 (3.89 g, 102 mmol., 3.00 equiv.) was then added portion-wise cautiously. The reaction mixture was heated to reflux for 1 hour. The flask was removed from the heat bath and potassium hydroxide (4.39 g, 78.2 mmol., 2.30 equiv.) was added slowly to the reaction mixture with vigorous stirring. The suspension was stirred at reflux for 30 minutes before adding dimethyl sulfate (16 mL, 170 mmol., 5.0 equiv.), and the suspension was refluxed for 64 hours. The reaction mixture was cooled to room temperature and diluted with water (75 mL) and diethyl ether (500 mL) and more water (300 mL). The organic layer was washed with brine (200 mL), dried with MgSO4 and concentrated. The crude material was purified by silica gel column chromatography (solid loading, gradient of 1:1 to 1:2 hexanes-dichloromethane) to give a white solid (5.314 g, 62% yield). 1H NMR (400 MHz, CDCl3) δ 7.52 (d, J=5.5 Hz, 2H), 7.41 (d, J=5.5 Hz, 2H), 2.81 (d, J=6.7, 2H), 4.15 (s, 6H).

出典