Calcium Carbonate → 3,4-Difluorobenzaldehyde

HRID 1939349Notes

Reaction equation

HRID 1939349 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

Procedure

In a 250 ml three-necked flask equipped with a magnetic stirrer, thermometer, condenser, and dropping funnel is placed 25.6 g (0.2 mol) of 3,4-difluorotoluene. The liquid is heated to 105° and illuminated as 67 g (0.42 mol) of bromine 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 approx. a 2 hour period, and the temperature is raised to 150° and kept there for 5 minutes. The reaction mixture is cooled and transferred to a 1 liter 3-necked flask with a motor driven stirrer and condenser. 120 ml H2O and 90 g of calcium carbonate are added, and the mixture is refluxed for 20 h 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 which is used without further purification.

Workup

  1. customIn a 250 ml three-necked flask equipped with a magnetic stirrer
  2. customthermometer, condenser, and dropping
  3. customfunnel is placed
  4. temperatureThe liquid is heated to 105°
  5. additionis added slowly
  6. additionis added over a period of one hour
  7. temperaturethe temperature is raised to 150°
  8. waitkept there for 5 minutes
  9. temperatureThe reaction mixture is cooled
  10. customtransferred to a 1 liter 3-necked flask with a motor
  11. temperaturethe mixture is refluxed for 20 h with good stirring
  12. distillationdistilled until no further oil
  13. customis collected
  14. dry with materialdried over MgSO4
  15. customEvaporation of the solvent

Sources & evidence

ORD record
ord-8536c5e08d4d46c88a682022b4cf77f1
Source dataset
uspto-grants-1997_12
Patent number
US05696159

Reaction notes

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