Hydrochloric Acid → 3-Acetyl-4-hydroxybenzoic acid

HRID 635905Notes

Reaction equation

HRID 635905 reaction equation
[Al+3].[Cl-].[Cl-].[Cl-].C([O:8][C:9]1[CH:17]=[CH:16][C:12]([C:13]([OH:15])=[O:14])=[CH:11][CH:10]=1)(=O)C.[C:18](Cl)(=[O:20])[CH3:19].Cl>ClC1C=CC(Cl)=CC=1Cl>[C:18]([C:17]1[CH:16]=[C:12]([CH:11]=[CH:10][C:9]=1[OH:8])[C:13]([OH:15])=[O:14])(=[O:20])[CH3:19]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 6367Acetyl chlorideHCID 16865Benzoic acid, 4-(acetyloxy)-HCID 6451240Aluminum(III) Chloride

Product 1

HCID 91792453-Acetyl-4-hydroxybenzoic acid

Reagents, catalysts & solvents 1

HCID 131,2,4-TrichlorobenzeneSolvent

Conditions

Temperature
135 °C

Procedure

36.6 g (0.274 mol) of AlCl3 are suspended in 50 ml of 1,2,4-trichloro-benzene and treated with 9 g (50 mmol) of 4-acetoxybenzoic acid. After dropwise addition of 7.84 g (0.1 mol) of acetyl chloride, the reaction mixture is heated to 130-140° C., the evolution of HCl gas occurring from approximately 60° C. The mixture is stirred for approximately 1 hour at 130° C. and then allowed to cool to 60-70° C., and the mixture is poured cautiously into stirred ice water. It is extracted several times with ethyl acetate, then the combined organic phases are extracted with saturated aqueous sodium bicarbonate solution and the combined aqueous phases are adjusted carefully to pH<1 using concentrated HCl, the 3-acetyl-4-hydroxybenzoic acid separating as sparingly soluble material.

Workup

  1. customoccurring from approximately 60° C
  2. temperatureto cool to 60-70° C.
  3. additionthe mixture is poured cautiously
  4. extractionIt is extracted several times with ethyl acetate
  5. extractionthe combined organic phases are extracted with saturated aqueous sodium bicarbonate solution

Sources & evidence

ORD record
ord-32b4594bab174a5b8714095c22992b82
Source dataset
uspto-grants-2001_02
Patent number
US06191164B1

Reaction notes

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