Pinacolone → 4-Chlorobenzoic Acid

HRID 1243976Notes

Reaction equation

HRID 1243976 reaction equation
CC(=[O:7])C(C)(C)C.[OH-].[Na+].[Cl:10][C:11]1[CH:18]=[CH:17][C:14]([CH:15]=[O:16])=[CH:13][CH:12]=1>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.O>[Cl:10][C:11]1[CH:18]=[CH:17][C:14]([C:15]([OH:7])=[O:16])=[CH:13][CH:12]=1.[Cl:10][C:11]1[CH:18]=[CH:17][C:14]([CH:15]=[O:16])=[CH:13][CH:12]=1

Participants

7

Reactant 3

HCID 6416Pinacolone2×HCID 77264-ChlorobenzaldehydeHCID 14798Sodium Hydroxide

Product 2

HCID 63184-Chlorobenzoic AcidHCID 77264-Chlorobenzaldehyde

Reagents, catalysts & solvents 2

HCID 74236Tetrabutylammonium BromideCatalystHCID 962WaterSolvent

Conditions

Temperature
50 °C

Procedure

Pinacolone (400.0 g, 94% pure, 3.76 moles), NaOH (40.0 g, 40 wt % in water, 0.40 moles), tetrabutylammonium bromide (6.0 g, 98% pure, 0.018 moles) and water (2.0 g) were charged into a 2 liter oil-jacketed cylindrical reactor fitted with a mechanical stirrer, thermometer, steam-jacketed addition funnel and a reflux condenser. The reactants were heated to 50° C. and then melted p-chlorobenzaldehyde (280.0 g, 98% pure, 1.95 moles) was added to the reaction mixture via the addition funnel uniformly over 30 minutes. After the addition of the aldehyde was complete, the temperature of the reaction mixture was raised to 60° C. and heated at that temperature for 4 hours. Analysis of the reaction mixture by LC (after neglecting the pinacolone and a small amount of p-chlorobenzoic acid formed by air oxidation of the p-chlorobenzaldehyde) indicated that the organic phase contained 96.2% Phenyl aldol and 0.2% unreacted p-chlorobenzaldehyde. The reaction mixture was then neutralized with 50% aqueous sulfuric acid to pH 8.79 and subjected to steam distillation with the oil temperature in the jacket set to 120° C. to recover all the excess pinacolone. The phases were allowed to settle and the lower (aqueous) phase was discarded. The upper (organic) phase was collected as the product Phenyl aldol.

Workup

  1. customfitted with a mechanical stirrer
  2. temperaturethe temperature of the reaction mixture was raised to 60° C.
  3. temperatureheated at that temperature for 4 hours

Sources & evidence

ORD record
ord-755f4b3fe4b54ee98ce2212f8adf5d1e
Source dataset
uspto-grants-2006_10
Patent number
US07119234B2

Reaction notes

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