Hydrochloric Acid → 4-(2'-fluoro-5'-chlorophenyl)-4-oxo-2E-butenoic acid

HRID 234816

Reaktionsgleichung

Reaktionsgleichung von HRID 234816
[C:1]1(=[O:7])[O:6][C:4](=[O:5])[CH:3]=[CH:2]1.[Cl:8][C:9]1[CH:14]=[CH:13][C:12]([F:15])=[CH:11][CH:10]=1.[Cl-].[Al+3].[Cl-].[Cl-].Cl>>[F:15][C:12]1[CH:13]=[CH:14][C:9]([Cl:8])=[CH:10][C:11]=1[C:1](=[O:7])/[CH:2]=[CH:3]/[C:4]([OH:6])=[O:5]

Komponenten

5

Edukt 4

HCID 313Hydrochloric AcidHCID 7923Maleic AnhydrideHCID 9604Benzene, 1-chloro-4-fluoro-HCID 6451240Aluminum(III) Chloride

Produkt 1

HCID 108232704-(2'-fluoro-5'-chlorophenyl)-4-oxo-2E-butenoic acid

Versuchsvorschrift

Finely pulverized maleic anhydride (3.0 g) is added portionwise to a mixture of 1-chloro-4-fluorobenzene (24.6 g) and anhydrous aluminium chloride (11.56 g). A gas bubbler is attached to the top of the condenser and the mixture is heated in an oil bath at 80°-85° C. for 2 hours at which time little hydrogen chloride gas evolution is evident. The mixture is cooled and the excess 1-chloro-4-fluorobenzene is recovered by distillation at water aspirator pressure. The resultant mixture is quenched with ice and then steam distilled to remove the last traces of the 1-chloro-4-fluorobenzene. Concentrated hydrochloric acid (10 mL) is added to the cooled mixture and the resultant solid collected by filtration (9.2 g). This material is taken up in boiling benzene (50 mL), treated with decolorizing charcoal and filtered through a celite bed. On standing overnight, the yellow solid is collected by filtration (2.45 g). A second recrystallization from benzene (40 mL) leads to 4-(2'-fluoro-5'-chlorophenyl)-4-oxo-2E-butenoic acid (2.1 g) as pure regioisomer.

Aufarbeitung

  1. temperatureThe mixture is cooled
  2. distillationthe excess 1-chloro-4-fluorobenzene is recovered by distillation at water aspirator pressure
  3. customThe resultant mixture is quenched with ice
  4. distillationsteam distilled
  5. customto remove the last traces of the 1-chloro-4-fluorobenzene
  6. additionConcentrated hydrochloric acid (10 mL) is added to the cooled mixture
  7. filtrationthe resultant solid collected by filtration (9.2 g)
  8. additiontreated with decolorizing charcoal
  9. filtrationfiltered through a celite bed
  10. filtrationthe yellow solid is collected by filtration (2.45 g)
  11. customA second recrystallization from benzene (40 mL)

Quellen und Nachweise

ORD-Eintrag
ord-ff49ab663d7f4e0ca144a2d5ec31f538
Quelldatensatz
uspto-grants-1997_01
Patentnummer
US05596097

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