1,4-Dichlorobenzene → 2,5-Dichlorobenzophenone

HRID 248655Notes

Reaction equation

HRID 248655 reaction equation
[OH-].[Na+].[Cl:3][C:4]1[CH:9]=[CH:8][C:7]([Cl:10])=[CH:6][CH:5]=1.[C:11](Cl)(=[O:18])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.[Cl-].[Al+3].[Cl-].[Cl-]>O>[Cl:3][C:4]1[CH:9]=[CH:8][C:7]([Cl:10])=[CH:6][C:5]=1[C:11]([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:18]

Participants

6

Reactant 4

HCID 46851,4-Dichlorobenzene2×HCID 7412Benzoyl chloride2×HCID 14798Sodium HydroxideHCID 6451240Aluminum(III) Chloride2×

Product 1

HCID 4581882,5-DichlorobenzophenoneYield 80%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
80 °C

Procedure

To a 22 L, three-necked flask fitted with a thermometer, mechanical stirrer and a Vigreux column connected to an aqueous NaOH scrubbing tower, was added 1,4-dichlorobenzene (3 Kg, 26.4 mol) and benzoyl chloride (2.6 Kg, 18.55 mol). The mixture was heated to 80° C. to give a homogeneous solution. Aluminum chloride (5.5 Kg, 41.25 mol) was added over 12 min. with stirring. (The molar ratio of reactants was 2.2:1.4:1.0 (AlCl3 : Dichlorobenzene:Benzoyl Chloride)). The resulting mixture was heated to 140° C. over 60 min followed by heating to 175° C. over 30 min. Heating was stopped at 175° C. The mixture was allowed to cool to 80° C. over two hours and poured into a well stirred mixture of ice and water (ca. 25 L water and 15 Kg of ice) over 30 min. The organic solid was collected by filtration and dissolved in 7 L of toluene. The solution was washed with aqueous sodium bicarbonate and dried. Toluene was removed by distillation. Pure 2,5-dichlorobenzophenone was isolated in 80% yield after recrystallization from hexane and toluene. Gas chromatography indicated an absolute yield of 97%.

Workup

  1. customTo a 22 L, three-necked flask fitted with a thermometer, mechanical stirrer
  2. customto give a homogeneous solution
  3. temperatureThe resulting mixture was heated to 140° C. over 60 min
  4. temperatureby heating to 175° C. over 30 min
  5. temperatureHeating
  6. customwas stopped at 175° C
  7. temperatureto cool to 80° C. over two hours
  8. additionpoured into a well
  9. stirringstirred
  10. filtrationThe organic solid was collected by filtration
  11. dissolutiondissolved in 7 L of toluene
  12. washThe solution was washed with aqueous sodium bicarbonate
  13. customdried
  14. customToluene was removed by distillation

Sources & evidence

ORD record
ord-4585f56064884c37a14842326880a65e
Source dataset
uspto-grants-1993_05
Patent number
US05210313

Reaction notes

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