Water → 3-Chlorobenzoic Acid

HRID 1419621Notes

Reaction equation

HRID 1419621 reaction equation
Cl[C:2]1[CH:10]=[CH:9][C:8]([Cl:11])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].S(=O)(=O)(O)O.O>[Cu].C1(C)C=CC=CC=1>[Cl:11][C:8]1[CH:7]=[C:3]([CH:2]=[CH:10][CH:9]=1)[C:4]([OH:6])=[O:5]

Participants

6

Reactant 3

HCID 962WaterHCID 1118Sulfuric AcidHCID 57842,5-Dichlorobenzoic acid

Product 1

HCID 4473-Chlorobenzoic AcidYield 85.1%

Reagents, catalysts & solvents 2

HCID 23978CopperCatalyst2×HCID 1140TolueneSolvent

Procedure

A 100-mL round-bottom flask was equipped with a magnetic stir bar, reflux condenser, thermometer, nitrogen inlet, and heating mantle attached to a temperature controller. The flask was charged with 2,5-dichlorobenzoic acid (5.0 g, 26.2 mmol) and copper powder (5.0 g, 78.5 mmol). Sulfuric acid (98%; 35 mL) was added, and the resulting mixture was heated to 130°-135° C. Additional copper (0.83 g, 13.1 mmol) was added after 1 hour in order to complete the delhalogenation. The reaction was monitored by GC analysis and was judged to be complete when the starting material was no longer detectable (1.5 hours). The reaction mixture was cooled to room temperature and transferred to a 500-mL Erlenmeyer flask. Water (100 mL) and toluene (100 mL) were added. The resulting mixture was filtered and the solids were washed with toluene. The filtrates were blue-green. The filtrates were combined and washed with 1M hydrochloric acid solution until the blue-green color disappeared. The resulting pale tan organic layer was washed with water and dried over sodium sulfate. The solvent was removed by evaporation under reduced pressure. The residue was dried under vacuum, affording 3.49 g of 3-chlorobenzoic acid as a white solid, mp 152°-153° C.

Workup

  1. customA 100-mL round-bottom flask was equipped with a magnetic stir bar
  2. temperaturereflux condenser
  3. temperaturethermometer, nitrogen inlet, and heating mantle
  4. temperaturethe resulting mixture was heated to 130°-135° C
  5. custom(1.5 hours)
  6. filtrationThe resulting mixture was filtered
  7. washthe solids were washed with toluene
  8. washwashed with 1M hydrochloric acid solution until the blue-green color
  9. washThe resulting pale tan organic layer was washed with water
  10. dry with materialdried over sodium sulfate
  11. customThe solvent was removed by evaporation under reduced pressure
  12. customThe residue was dried under vacuum

Sources & evidence

ORD record
ord-f5597da570b3488386fe56e329e083a4
Source dataset
uspto-grants-1999_03
Patent number
US05886210

Reaction notes

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