Dichloroacetic Acid → 5-Chloro-2-(dichloromethyl)-1H-benzimidazole-6-sulfonamide

HRID 904848Notes

Reaction equation

HRID 904848 reaction equation
[NH2:1][C:2]1[CH:8]=[C:7]([Cl:9])[C:6]([S:10](=[O:13])(=[O:12])[NH2:11])=[CH:5][C:3]=1[NH2:4].[Cl:14][CH:15]([Cl:19])[C:16](O)=O>Cl.O>[Cl:9][C:7]1[C:6]([S:10](=[O:12])(=[O:13])[NH2:11])=[CH:5][C:3]2[NH:4][C:16]([CH:15]([Cl:19])[Cl:14])=[N:1][C:2]=2[CH:8]=1

Participants

5

Reactant 2

HCID 6597Dichloroacetic AcidHCID 132896884,5-Diamino-2-chlorobenzene-1-sulfonamide

Product 1

HCID 132897055-Chloro-2-(dichloromethyl)-1H-benzimidazole-6-sulfonamideYield 26.9%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 962WaterSolvent

Procedure

To 11.8 g of 2-amino-4-chloro-5-sulfamyl aniline in 50 ml of 4 N hydrochloric acid was added 20.5 g of dichloroacetic acid and the suspension refluxed for 6 hours. Concentration in vacuo provided a dark viscous oil which was suspended in 150 ml of water and crystallized through vigorous scratching. The dark brown solid was then dissolved in methanol, the solution brought to a boil, and charcoal added. After boiling for five minutes, the suspension was filtered through filter paper, cooled and then filtered through Celite. Concentration in vacuo gave a viscous oil which upon setting at ambient temperature for 48 hours crystallized. Tritration with acetonitrile provided 4.5 g of beige crystals, m.p. 225°-227°.

Workup

  1. temperaturethe suspension refluxed for 6 hours
  2. concentrationConcentration in vacuo
  3. customprovided a dark viscous oil which
  4. customcrystallized
  5. dissolutionThe dark brown solid was then dissolved in methanol
  6. additionadded
  7. filtrationthe suspension was filtered
  8. filtrationthrough filter paper
  9. temperaturecooled
  10. filtrationfiltered through Celite
  11. concentrationConcentration in vacuo
  12. customgave a viscous oil which
  13. waitupon setting at ambient temperature for 48 hours
  14. customcrystallized

Sources & evidence

ORD record
ord-5801849e07c1422fa1311a600f640156
Source dataset
uspto-grants-1983_12
Patent number
US04420487

Reaction notes

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