Dimethylformamide → 2-Fluoro-5-methoxypyridine

HRID 1812351Notes

Reaction equation

HRID 1812351 reaction equation
[F:1][C:2]1[N:7]=[CH:6][C:5]([OH:8])=[CH:4][CH:3]=1.[C:9](=O)([O-])[O-].[K+].[K+].CI.CN(C=O)C>O>[F:1][C:2]1[CH:3]=[CH:4][C:5]([O:8][CH3:9])=[CH:6][N:7]=1

Participants

6

Conditions

Temperature
45 °C

Procedure

To a 20 mL microwave vial, 6-fluoropyridin-3-ol (Alfa Aesar, 1.04 g, 9.18 mmol), potassium carbonate (1.90 g, 13.8 mmol) and methyl iodide (Aldrich, 0.689 mL, 11.0 mmol) were mixed into DMF (6 mL). The brown mixture was stirred at 45° C. for 2.5 h. The mixture was diluted with water and the aqueous phase was extracted with EtOAc (3×20 mL). The combined organic phases were washed with saturated aqueous sodium chloride (30 mL). The organic phase was dried over sodium sulfate, filtered and concentrated in vacuo to afford 2-fluoro-5-methoxypyridine (1.08 g, 92% yield) as a light brown oil. This material was used in the next reaction without further purification. 1H NMR (400 MHz, CDCl3) δ ppm 7.79-7.85 (m, 1H) 7.33 (td, J=6.02, 3.23 Hz, 1H) 6.86 (dd, J=8.90, 3.42 Hz, 1H) 3.85 (s, 3H). m/z (ESI, positive ion): 128.1 (M+H)+.

Workup

  1. extractionthe aqueous phase was extracted with EtOAc (3×20 mL)
  2. washThe combined organic phases were washed with saturated aqueous sodium chloride (30 mL)
  3. dry with materialThe organic phase was dried over sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-eef6f4cbfaff4521ba61b64143b9fe7e
Source dataset
uspto-grants-2013_01
Patent number
US08362241B2

Reaction notes

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