Sulfuric Acid → 4,4'-Difluorobenzophenone

HRID 1302

Reaktionsgleichung

Reaktionsgleichung von HRID 1302
[CH:1]1[C:6]([CH2:7][C:8]2[CH:13]=[CH:12][C:11]([F:14])=[CH:10][CH:9]=2)=[CH:5][CH:4]=[C:3]([F:15])[CH:2]=1.[OH:16]S(O)(=O)=O.C1(C)C=CC=CC=1>O.O=[Mn]=O>[F:15][C:3]1[CH:2]=[CH:1][C:6]([C:7]([C:8]2[CH:13]=[CH:12][C:11]([F:14])=[CH:10][CH:9]=2)=[O:16])=[CH:5][CH:4]=1

Komponenten

6

Edukt 3

HCID 1118Sulfuric Acid2×HCID 1140TolueneHCID 960941,1'-Methylenebis[4-fluorobenzene]

Produkt 1

HCID 95824,4'-DifluorobenzophenoneAusbeute 69,2 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 14801Manganese dioxideKatalysatorHCID 962WaterLösungsmittel3×

Reaktionsbedingungen

Temperatur
125 °C

Versuchsvorschrift

To a 250 mL round bottomed flask equipped with a heating mantle, overhead agitator, thermometer, condenser, and addition funnel with a tube protruding below the liquid level was added 10.6 g 4,4'-difluorodiphenylmethane (0.051 moles). Agitation was begun and a slurry of 20.5 g MnO2 (0.195 moles) in 30 g water was added to the flask. About 30 g of water were used to wash the MnO2 beaker and were added to the flask. The mixture was allowed to reach about 100° C. at which point 50 g H2SO4 (0.487 moles) were added to the addition funnel. The H2SO4 was then added dropwise into the flask and the reaction temperature slowly rose to about 125° C. when all of the acid had been added. The mixture was heated to maintain the temperature at about 125° C. until gas chromatography showed complete conversion after approximately 12 hours. The reaction mixture was allowed to cool to 100° C. and 50 g toluene were added to the mixture. A slurry of 6 g diatomaceous earth in 30 g water was poured into a vacuum Buchner funnel fitted with No. 42 filter paper to form a filter pre-coat. The contents of the round bottomed flask were then vacuum filtered. 10 g toluene was used to wash the flask and, subsequently, the filter cake. The filter cake was then washed with 100 g toluene heated to about 50° to 70° C. and the filtrate phase separated. The toluene was removed from the organic phase by heating to approximately 65° C. at 10 mm Hg. The 10 g yellow solids assayed as 95% pure 4,4'-difluorobenzophenone for an 84% yield. The solids were recrystallized from a hexane solvent leaving 7.7 g crystalline 4,4'-difluorobenzophenone for a 68% yield.

Aufarbeitung

  1. customTo a 250 mL round bottomed flask equipped with a heating mantle, overhead agitator
  2. additionthermometer, condenser, and addition funnel with a tube protruding below the liquid level
  3. washto wash the MnO2 beaker
  4. additionwere added to the flask
  5. customto reach about 100° C. at which
  6. additionwere added to the addition funnel
  7. customslowly rose to about 125° C.
  8. additionhad been added
  9. temperatureThe mixture was heated
  10. customafter approximately 12 hours
  11. temperatureto cool to 100° C.
  12. customfitted with No
  13. filtration42 filter paper
  14. customto form a filter pre-coat
  15. filtrationvacuum filtered
  16. washto wash the flask
  17. washThe filter cake was then washed with 100 g toluene
  18. temperatureheated to about 50° to 70° C.
  19. customthe filtrate phase separated
  20. customThe toluene was removed from the organic phase
  21. temperatureby heating to approximately 65° C. at 10 mm Hg
  22. customThe solids were recrystallized from a hexane solvent

Quellen und Nachweise

ORD-Eintrag
ord-d880e525dd19411dbb94deface4386f9
Quelldatensatz
uspto-grants-1998_03
Patentnummer
US05723676

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