Реакция #82977

Уравнение реакции

trichloroacetyl chloride

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

→

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

Растворители

xylene

Условия реакции

Обработка

1. 1
   Другоеobtained
2. 2
   ТемператураThe mixture is then heated
3. 3
   Температураat reflux for two hours until the product which
4. 4
   Другоеhas initially precipitated
5. 5
   workup.DISSOLUTIONis completely dissolved
6. 6
   ТемператураCool
7. 7
   Фильтрацияfilter
8. 8
   КонцентрированиеConcentrate the mother liquors
9. 9
   workup.ADDITIONadd petroleum ether
10. 10
    ДругоеCombine with the precipitate obtained earlier
11. 11
    ДругоеThe combined precipitates
12. 12
    workup.ADDITIONare treated with an aqueous solution of sodium hydrogen carbonate
13. 13
    Другоеrecrystallised from ethyl acetate

Методика

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.

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