تفاعل #82977

معادلة التفاعل

trichloroacetyl chloride

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

→

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

المذيبات

xylene

ظروف التفاعل

المعالجة

1. 1
   أخرىobtained
2. 2
   درجة الحرارةThe mixture is then heated
3. 3
   درجة الحرارةat reflux for two hours until the product which
4. 4
   أخرىhas initially precipitated
5. 5
   workup.DISSOLUTIONis completely dissolved
6. 6
   درجة الحرارةCool
7. 7
   ترشيحfilter
8. 8
   تركيزConcentrate the mother liquors
9. 9
   workup.ADDITIONadd petroleum ether
10. 10
    أخرىCombine with the precipitate obtained earlier
11. 11
    أخرىThe combined precipitates
12. 12
    workup.ADDITIONare treated with an aqueous solution of sodium hydrogen carbonate
13. 13
    أخرىrecrystallised from ethyl acetate

الإجراء التجريبي

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.

المصدر