Bromine → 1,5-Dibromo-2,4-difluorobenzene

HRID 1907421Notes

Reaction equation

HRID 1907421 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([F:8])=[CH:4][C:3]=1[F:9].[Br:10]Br.[O-]S([O-])(=S)=O.[Na+].[Na+]>C(Cl)Cl.[Fe]>[Br:1][C:2]1[CH:7]=[C:6]([Br:10])[C:5]([F:8])=[CH:4][C:3]=1[F:9]

Participants

6

Reactant 3

HCID 24408BromineHCID 24477Sodium ThiosulfateHCID 676741-Bromo-2,4-difluorobenzene

Product 1

HCID 105645111,5-Dibromo-2,4-difluorobenzeneYield 86%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 1-bromo-2,4-difluorobenzene (19.3 mL, 171 mmol) in CH2Cl2 (100 mL) was added iron (3.15 g, 56 mmol). To this stirred suspension was added a solution of bromine (11 mL, 214 mmol) in CH2Cl2 (25 mL) drop wise over 30 min. The resulting mixture was stirred at rt overnight. The reaction mixture was slowly poured into saturated aqueous Na2S2O3 (200 mL), and the resulting mixture was stirred at rt for 30 min. This was extracted with CH2Cl2 (3×80 mL). The combined extracts were washed with brine, dried over MgSO4, filtered and concentrated in vacuo to give 1,5-dibromo-2,4-difluorobenzene (40 g, 86% yield) as a brown oil. 1H NMR (500 MHz, CHLOROFORM-d) δ 7.79 (t, J=7.0 Hz, 1H), 7.00 (t, J=8.2 Hz, 1H).

Workup

  1. stirringthe resulting mixture was stirred at rt for 30 min
  2. extractionThis was extracted with CH2Cl2 (3×80 mL)
  3. washThe combined extracts were washed with brine
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-01f62c10d4624ec2a16bef654f9a3afa
Source dataset
uspto-grants-2013_12
Patent number
US08598161B2

Reaction notes

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