Reaktion #335837

Reaktionsgleichung

NaOH

1,4-dichlorobenzene

benzoyl chloride

AlCl3

Aluminum chloride

Dichlorobenzene

Benzoyl Chloride

→

2,5-dichlorobenzophenone

Ausbeute 80.0%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeTo a 22 L, three-necked flask fitted with a thermometer, mechanical stirrer
2. 2
   Sonstigeto give a homogeneous solution
3. 3
   TemperaturThe resulting mixture was heated to 140° C. over 60 min
4. 4
   Temperaturby heating to 175° C. over 30 min
5. 5
   TemperaturHeating
6. 6
   Sonstigewas stopped at 175° C
7. 7
   Temperaturto cool to 80° C. over two hours
8. 8
   workup.ADDITIONpoured into a well
9. 9
   workup.STIRRINGstirred
10. 10
    FiltrationThe organic solid was collected by filtration
11. 11
    workup.DISSOLUTIONdissolved in 7 L of toluene
12. 12
    WaschenThe solution was washed with aqueous sodium bicarbonate
13. 13
    Sonstigedried
14. 14
    SonstigeToluene was removed by distillation

Vorschrift

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%.

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