Bromine → 1-Bromo-2,5-difluoro-4-methylbenzene

HRID 1266364Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1266364
[F:1][C:2]1[CH:7]=[CH:6][C:5]([F:8])=[CH:4][C:3]=1[CH3:9].[Br:10]Br>CCOCC.[Fe]>[Br:10][C:6]1[CH:7]=[C:2]([F:1])[C:3]([CH3:9])=[CH:4][C:5]=1[F:8]

Komponenten

5

Edukt 2

HCID 24408BromineHCID 679802,5-Difluorotoluene

Produkt 1

HCID 27829131-Bromo-2,5-difluoro-4-methylbenzene

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 23925IronKatalysatorHCID 3283Diethyl EtherLösungsmittel

Reaktionsbedingungen

Temperatur
-5 °C

Versuchsvorschrift

A mixture of 2,5-difluorotoluene (25 g, 0.20 mol) and iron powder (11 g, 0.2 mol) was cooled to −5° C. Bromine was added dropwise such that the internal temperature of the reaction did not rise above 0° C. After stirring for 3 hours, the mixture was diluted with ether, filtered and washed with aqueous sodium thiosulfate solution. The aqueous layer was extracted with ether, and the combined organic layers were dried over MgSO4, filtered and concentrated in vacuo. Distillation at atmospheric pressure gave 34 g of 1-bromo-2,5-difluoro-4-methyl-benzene as a colorless oil (b.p. 180 oC). 1H NMR (300 MHz, CDCl3) δ 7.20 (dd, 1H, J=6.0, 8.5 Hz), 6.93 (m,1H), 2.23 (s, 3H) ppm.

Aufarbeitung

  1. customdid not rise above 0° C
  2. filtrationfiltered
  3. washwashed with aqueous sodium thiosulfate solution
  4. extractionThe aqueous layer was extracted with ether
  5. dry with materialthe combined organic layers were dried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. distillationDistillation at atmospheric pressure

Quellen und Nachweise

ORD-Eintrag
ord-5ef447a9a28b4d398da3ece6d96d7f4d
Quelldatensatz
uspto-grants-2003_04
Patentnummer
US06548526B2

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