Ammonium fluoride → 2-FLUORO-4-METHYLBIPHENYL

HRID 905155Notes

Reaction equation

HRID 905155 reaction equation
N[C:2]1[CH:7]=[C:6]([CH3:8])[CH:5]=[CH:4][C:3]=1[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.[NH4+].[F-:16].N([O-])=O.[Na+]>>[F:16][C:2]1[CH:7]=[C:6]([CH3:8])[CH:5]=[CH:4][C:3]=1[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1

Participants

4

Reactant 3

HCID 25516Ammonium fluorideHCID 125594574-Methyl[1,1'-biphenyl]-2-amineHCID 23668193Sodium Nitrite

Product 1

HCID 108993662-FLUORO-4-METHYLBIPHENYL

Procedure

To a cold (ice-salt bath) solution of 21.3 g (0.115 mol) of 2-amino-4-methylbiphenyl (prepared in Example 2) and 6.5 g (0.11 mol) of NH4F.HF and 75 g of 70% HF (2.6 mol) was portion-wise added 8.9 g (0.13 mol) of NaNO2 so that the temperature of the reaction mixture did not rise above 5°. This solution took approximately 40 minutes. The reaction mixture was allowed to stir at 0° for 15 minutes thereafter, and then the cooling bath was removed and stirring continued. The temperature rose to 15° after 20 minutes and then to 60° over a subsequent 25 minute period during which time nitrogen was evolved. The reaction mixture was cooled in an ice bath and extracted three times with petroleum ether. This organic extract was washed successively with water, aqueous NaHCO3, and H2O and then dried over MgSO4 which, after concentration left 18.8 g of dark red liquid. Subsequent analysis of this material by gas chromatography showed the fluoride compound present at about 90% by weight and about 6% by weight of the corresponding hydroxy compound. A solution of the crude product in petroleum ether was passed through a short column of silica gel. Removal of the solvent at reduced pressure left 16.6 g of pure 2-fluoro-4-methylbiphenyl (78%) as a colorless liquid.

Workup

  1. customdid not rise above 5°
  2. customthe cooling bath was removed
  3. stirringstirring
  4. waitThe temperature rose to 15° after 20 minutes
  5. waitto 60° over a subsequent 25 minute period during which time nitrogen was evolved
  6. temperatureThe reaction mixture was cooled in an ice bath
  7. extractionextracted three times with petroleum ether
  8. extractionThis organic extract
  9. washwas washed successively with water, aqueous NaHCO3, and H2O
  10. dry with materialdried over MgSO4 which
  11. concentrationafter concentration
  12. waitleft 18.8 g of dark red liquid
  13. customRemoval of the solvent at reduced pressure
  14. waitleft 16.6 g of pure 2-fluoro-4-methylbiphenyl (78%) as a colorless liquid

Sources & evidence

ORD record
ord-ccfc019038094fcb9bbf6c3c0c3a510f
Source dataset
uspto-grants-1983_12
Patent number
US04422979

Reaction notes

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