Hydrochloric Acid → 5-Chloro-2-(difluoromethyl)-1H-benzimidazole-6-sulfonamide

HRID 904856Notes

Reaction equation

HRID 904856 reaction equation
Cl.[NH2:2][C:3]1[CH:9]=[C:8]([Cl:10])[C:7]([S:11](=[O:14])(=[O:13])[NH2:12])=[CH:6][C:4]=1[NH2:5].[F:15][CH:16]([F:20])[C:17](O)=O>O>[Cl:10][C:8]1[C:7]([S:11](=[O:13])(=[O:14])[NH2:12])=[CH:6][C:4]2[NH:5][C:17]([CH:16]([F:20])[F:15])=[N:2][C:3]=2[CH:9]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 9788Difluoroacetic acidHCID 132896884,5-Diamino-2-chlorobenzene-1-sulfonamide

Product 1

HCID 132897205-Chloro-2-(difluoromethyl)-1H-benzimidazole-6-sulfonamide

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To 25 ml of 6 N hydrochloric acid containing 2.22 g of 2-amino-4-chloro-5-sulfamylaniline was added 1.50 g of difluoroacetic acid and the mixture refluxed for 12 hours. The resultant solid was collected by filtration and then added to concentrated ammonium hydroxide to yield the free base which was then suspended in water at 50° C. The solid was then collected by filtration, dissolved in methanol, the methanol brought to a boil, charcoal added, and the suspension filtered through two sheets of filter paper, and then through Celite. Concentration in vacuo provided a brown solid which upon recrystallization from acetonitrile yielded a pink solid, m.p. 233°-235°.

Workup

  1. temperaturethe mixture refluxed for 12 hours
  2. filtrationThe resultant solid was collected by filtration
  3. additionadded to concentrated ammonium hydroxide
  4. customto yield the free base which
  5. filtrationThe solid was then collected by filtration
  6. dissolutiondissolved in methanol
  7. additionadded
  8. filtrationthe suspension filtered through two sheets of filter paper
  9. concentrationConcentration in vacuo
  10. customprovided a brown solid which
  11. customupon recrystallization from acetonitrile
  12. customyielded a pink solid, m.p. 233°-235°

Sources & evidence

ORD record
ord-0074836a49664256af7146d6b8c8fa09
Source dataset
uspto-grants-1983_12
Patent number
US04420487

Reaction notes

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