Potassium Carbonate → 4-Fluoro-3-(pyridin-3-yl)aniline

HRID 1061746Notes

Reaction equation

HRID 1061746 reaction equation
Br[C:2]1[CH:3]=[C:4]([NH2:9])[CH:5]=[CH:6][C:7]=1[F:8].C(B(CC)[C:13]1[CH:14]=[N:15][CH:16]=[CH:17][CH:18]=1)C.C(=O)([O-])[O-].[K+].[K+]>COCCOC.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[F:8][C:7]1[CH:6]=[CH:5][C:4]([NH2:9])=[CH:3][C:2]=1[C:13]1[CH:14]=[N:15][CH:16]=[CH:17][CH:18]=1

Participants

7

Conditions

Temperature
80 °C

Procedure

A mixture of 3-bromo-4-fluorophenylamine (7.92 g, 41.7 mmol), diethyl(3-pyridyl)borane (6.74 g, 45.9 mmol), tetrakis(triphenylphosphine)palladium(0) (0.96 g, 0.83 mmol) and potassium carbonate (17.26 g, 125 mmol) in 1,2-dimethoxyethane (30 mL) and water (15 mL) was heated at 80° C. for 20 h. After cooling to ambient temperature the reaction was partitioned between ethyl acetate (500 mL) and water (500 mL). The organics were washed with brine (400 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. Purification of the residue by flash chromatography on silica gel, eluting with dichloromethane on a gradient of ethyl acetate (0%-20%) gave 4-fluoro-3-(pyridin-3-yl)phenylamine (3.64 g, 46%) as a colourless oil that solidified on standing to afford a white solid: δH (360 MHz, CDCl3) 3.65 (2H, s), 6.65-6.72 (2H, m), 6.99 (1H, dd, J 9 and 9), 7.33-7.37 (1H, m), 7.84-7.86 (1H, m), 8.58 (1H, d, J 4), 8.76 (1H, m).

Workup

  1. temperatureAfter cooling to ambient temperature the reaction
  2. customwas partitioned between ethyl acetate (500 mL) and water (500 mL)
  3. washThe organics were washed with brine (400 mL)
  4. dry with materialdried over anhydrous sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customPurification of the residue by flash chromatography on silica gel
  8. washeluting with dichloromethane on a gradient of ethyl acetate (0%-20%)

Sources & evidence

ORD record
ord-df6e68bd747041e8adbda2641b16c393
Source dataset
uspto-grants-2005_11
Patent number
US06960598B2

Reaction notes

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