反応 #82977

反応方程式

trichloroacetyl chloride

2,9-dimethylimidazo[1,2-a]benzimidazole

→

2,9-Dimethyl-3-trichloroacetylimidazo[1,2-a]benzimidazole

溶媒

xylene

反応条件

後処理

1. 1
   その他obtained
2. 2
   温度The mixture is then heated
3. 3
   温度at reflux for two hours until the product which
4. 4
   その他has initially precipitated
5. 5
   workup.DISSOLUTIONis completely dissolved
6. 6
   温度Cool
7. 7
   ろ過filter
8. 8
   濃縮Concentrate the mother liquors
9. 9
   workup.ADDITIONadd petroleum ether
10. 10
    その他Combine with the precipitate obtained earlier
11. 11
    その他The combined precipitates
12. 12
    workup.ADDITIONare treated with an aqueous solution of sodium hydrogen carbonate
13. 13
    その他recrystallised from ethyl acetate

実験手順

Pour 5.45 g (30 mmol) of freshly distilled trichloroacetyl chloride dropwise into a boiling solution of 2,9-dimethylimidazo[1,2-a]benzimidazole (3.7 g; 20 mmol)--obtained as described in Khim. Geterotsikl Soedin, 86, (7), 918-925--in 50 ml of xylene, with vigorous stirring, over a period of 20 to 30 minutes. The mixture is then heated at reflux for two hours until the product which has initially precipitated is completely dissolved. Cool and filter. Concentrate the mother liquors and add petroleum ether. Combine with the precipitate obtained earlier and repeat the operation. The combined precipitates are treated with an aqueous solution of sodium hydrogen carbonate and then recrystallised from ethyl acetate.

出典