Hydrochloric Acid → 3-Chloro-2,4,5-trifluorobenzoic Acid

HRID 476771Notes

Reaction equation

HRID 476771 reaction equation
N[C:2]1[C:3]([F:13])=[C:4]([CH:8]=[C:9]([F:12])[C:10]=1[F:11])[C:5]([OH:7])=[O:6].[ClH:14].N([O-])=O.[Na+]>O>[Cl:14][C:2]1[C:3]([F:13])=[C:4]([CH:8]=[C:9]([F:12])[C:10]=1[F:11])[C:5]([OH:7])=[O:6]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 27359463-Amino-2,4,5-trifluorobenzoic acidHCID 23668193Sodium Nitrite

Product 1

HCID 27342693-Chloro-2,4,5-trifluorobenzoic AcidYield 83%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

3-Amino-2,4,5-trifluorobenzoic acid (Example 2), 0.52 g, and 3 g of cupric chloride are added to 10 ml of a 3% aqueous solution of hydrochloric acid and the mixture is stirred with ice bath cooling. A solution of 0.32 g of sodium nitrite in 4 ml of water is added to the reaction mixture in portions over a one-hour period while maintaining the reaction at 0°-5° C. The ice bath is then removed and the mixture is stirred for two hours at room temperature. Toluene, 20 ml, and 15 ml of water are added with stirring. The layers are separated and the aqueous layer extracted with 20 ml of toluene. The combined toluene extracts are extracted with 4 ml of a 36% aqueous solution of hydrochloric acid and then concentrated to a solid under reduced pressure to give 0.48 g (83%) of 3-chloro-2,4,5-trifluorobenzoic acid as a tan solid; GC (98.4%); HPLC (89.2%); recrystallization from heptanes gives 0.40 g (70%) of 3-chloro-2,4,5-trifluorobenzoic acid; mp 109°-111° C.

Workup

  1. temperaturecooling
  2. temperaturewhile maintaining
  3. customthe reaction at 0°-5° C
  4. customThe ice bath is then removed
  5. stirringthe mixture is stirred for two hours at room temperature
  6. additionToluene, 20 ml, and 15 ml of water are added
  7. stirringwith stirring
  8. customThe layers are separated
  9. extractionthe aqueous layer extracted with 20 ml of toluene
  10. extractionThe combined toluene extracts are extracted with 4 ml of a 36% aqueous solution of hydrochloric acid
  11. concentrationconcentrated to a solid under reduced pressure

Sources & evidence

ORD record
ord-151ae5d90f814d419ddca170d37a6327
Source dataset
uspto-grants-1989_12
Patent number
US04885386

Reaction notes

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