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

HRID 750574Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 750574
[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-3d2f98113a714585b552f54de4e08bc5
Quelldatensatz
uspto-grants-2008_07
Patentnummer
US07405218B2

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