反応 #985273

反応方程式

POCl3

sodium acetate

POCl3

Dimethylformamide

POCl3

N-ethylcarbazole

DMF

→

N-ethyl-3,6-diformylcarbazole

収率 46.0%

溶媒

water

反応条件

後処理

1. 1
   その他equipped with a mechanical stirrer
2. 2
   温度The contents were cooled in a salt/ice bath
3. 3
   その他reached 0° C.
4. 4
   その他to rise above 5° C
5. 5
   温度After the flask warmed to room temperature
6. 6
   温度the flask was heated to 90° C. for 24 hours
7. 7
   温度Next, the reaction mixture was cooled to room temperature
8. 8
   workup.ADDITIONthe reaction mixture was added slowly to a cooled 4.5 liter beaker
9. 9
   workup.ADDITIONcontaining a solution
10. 10
    温度The beaker was cooled in an ice bath
11. 11
    その他The brownish solid obtained
12. 12
    ろ過was filtered
13. 13
    洗浄washed repeatedly with water
14. 14
    洗浄After washing
15. 15
    その他the resulting product was recrystallized once from toluene using activated charcoal
16. 16
    その他dried under vacuum in an oven
17. 17
    温度heated at 70° C. for 6 hours

実験手順

Dimethylformamide (DMF, 271 ml, 3.5 mol, obtained from Aldrich, Milwaukee, Wis.) was added to a 1-liter 3-neck round-bottomed flask equipped with a mechanical stirrer, a thermometer, and a dropping funnel. The contents were cooled in a salt/ice bath. When the temperature inside the flask reached 0° C., 326 ml of POCl3 (3.5 mol) was slowly added. During the addition of POCl3, the temperature inside the flask was not allowed to rise above 5° C. After the addition of POCl3 was completed, the reaction mixture was allowed to warm to room temperature. After the flask warmed to room temperature, N-ethylcarbazole (93 g, obtained from Aldrich) in 70 ml of DMF was added, and then the flask was heated to 90° C. for 24 hours using a heating mantle. Next, the reaction mixture was cooled to room temperature and the reaction mixture was added slowly to a cooled 4.5 liter beaker containing a solution comprising 820 g of sodium acetate dissolved in 2 liters of water. The beaker was cooled in an ice bath and stirred for 3 hours. The brownish solid obtained was filtered and washed repeatedly with water, followed by a small amount of ethanol (50 ml). After washing, the resulting product was recrystallized once from toluene using activated charcoal and dried under vacuum in an oven heated at 70° C. for 6 hours to obtain 55 g (46% yield) of N-ethyl-3,6-diformylcarbazole. The 1H-NMR spectrum (250 MHz) of the product in CDCl3 was characterized by the following chemical shifts (δ, ppm): 10.12 (s, 2H); 8.63 (s, 2H); 8.07 (d, 2H); 7.53 (d, 2H); 4.45 (m, 2H); 1.53 (t, 3H).

出典