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

HRID 54699Notes

Reaction equation

HRID 54699 reaction equation
[Cl:1][C:2]([Cl:7])([Cl:6])[C:3](Cl)=[O:4].[CH3:8][C:9]1[N:10]=[C:11]2[N:15]([CH:16]=1)[C:14]1[CH:17]=[CH:18][CH:19]=[CH:20][C:13]=1[N:12]2[CH3:21]>C1(C)C(C)=CC=CC=1>[CH3:8][C:9]1[N:10]=[C:11]2[N:15]([C:16]=1[C:3](=[O:4])[C:2]([Cl:7])([Cl:6])[Cl:1])[C:14]1[CH:17]=[CH:18][CH:19]=[CH:20][C:13]=1[N:12]2[CH3:21]

Participants

4

Reactant 2

HCID 6420Trichloroacetyl chlorideHCID 8282692,4-Dimethylimidazo[1,2-a]benzimidazole

Product 1

HCID 190408122,9-Dimethyl-3-trichloroacetylimidazo[1,2-a]benzimidazole

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

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.

Workup

  1. customobtained
  2. temperatureThe mixture is then heated
  3. temperatureat reflux for two hours until the product which
  4. customhas initially precipitated
  5. dissolutionis completely dissolved
  6. temperatureCool
  7. filtrationfilter
  8. concentrationConcentrate the mother liquors
  9. additionadd petroleum ether
  10. customCombine with the precipitate obtained earlier
  11. customThe combined precipitates
  12. additionare treated with an aqueous solution of sodium hydrogen carbonate
  13. customrecrystallised from ethyl acetate

Sources & evidence

ORD record
ord-61de2979af5447788006ba4dcceb3672
Source dataset
uspto-grants-1997_04
Patent number
US05623073

Reaction notes

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