Calcium Carbonate → 3,4-Difluorobenzaldehyde

HRID 377743Notes

Reaction equation

HRID 377743 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([CH3:9])[CH:5]=[CH:6][C:7]=1[F:8].BrBr.C(=O)([O-])[O-:13].[Ca+2]>O>[F:1][C:2]1[CH:3]=[C:4]([CH:5]=[CH:6][C:7]=1[F:8])[CH:9]=[O:13]

Participants

5

Reactant 3

HCID 10112Calcium CarbonateHCID 24408Bromine3×HCID 27334003,4-Difluorotoluene

Product 1

HCID 5880883,4-Difluorobenzaldehyde

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
150 °C

Procedure

3,4-difluorotoluene (25.6 g, 0.2 mol) is heated to 105° C. in a 250 ml 3-necked flask equipped with a magnetic stirrer, thermometer, condenser, and dropping funnel, and is illuminated as bromine (67 g, 0.42 mol) is added slowly. The temperature is kept between 105-110° C. while the first half of the bromine is added over a period of one hour. The rest of the bromine is added over approximately a two-hour period, and the temperature is raised to 150° C., and is kept there for 5 minutes. The reaction mixture is cooled and is transferred to a 1 liter 3-necked flask with a motor-driven stirrer and condenser. H2O (120 ml) and calcium carbonate (90 g) are added, and the mixture is refluxed for 20 hours with good stirring. The reaction mixture is steam distilled until no further oil is collected. The oil is taken up in methylene chloride and dried over MgSO4. Evaporation of the solvent yields 3,4-difluorobenzaldehyde that is used without further purification.

Workup

  1. customequipped with a magnetic stirrer
  2. customthermometer, condenser, and dropping
  3. additionis added slowly
  4. additionis added over a period of one hour
  5. temperatureThe reaction mixture is cooled
  6. customis transferred to a 1 liter 3-necked flask with a motor-driven stirrer and condenser
  7. temperaturethe mixture is refluxed for 20 hours with good stirring
  8. distillationdistilled until no further oil
  9. customis collected
  10. dry with materialdried over MgSO4
  11. customEvaporation of the solvent

Sources & evidence

ORD record
ord-8fa636683d7f4e73b210a3cd5ada2796
Source dataset
uspto-grants-2000_02
Patent number
US06028116

Reaction notes

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