Ethyl Acetate → Methyl 6-fluoro-4-hydroxy-2-naphthoate

HRID 2363806Notes

Reaction equation

HRID 2363806 reaction equation
[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12]([OH:14])=[O:13])[CH:6]=[C:5]2[OH:15].S(Cl)(Cl)=O.[C:20](OCC)(=O)C>CO>[CH3:20][O:13][C:12]([C:7]1[CH:6]=[C:5]([OH:15])[C:4]2[C:9](=[CH:10][CH:11]=[C:2]([F:1])[CH:3]=2)[CH:8]=1)=[O:14]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 24386Thionyl ChlorideHCID 823722636-Fluoro-4-hydroxy-2-naphthoic acid

Product 1

HCID 59326505Methyl 6-fluoro-4-hydroxy-2-naphthoateYield 28%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of 6-fluoro-4-hydroxy-naphthalene-2-carboxylic acid (0.500 g, 2.42 mmol) in MeOH (10 mL) was added thionyl chloride (0.265 ml, 3.63 mmol) drop-wise at 0° C. and the resulting mixture was refluxed for 5 hours. Methanol was distilled off under reduced pressure, and the residue was diluted with water (5 mL) and extracted with ethyl acetate (2×10 mL). The combined organic extracts were washed with water (5 mL) followed by brine (5 mL), dried and concentrated under reduced pressure to obtain the crude product. Silica gel column chromatography (5% ethyl acetate in hexanes) afforded 6-fluoro-4-hydroxy-naphthalene-2-carboxylic acid methyl ester (0.150 g, 28%) as a light yellow solid. MS cald. for C12H10FO3 [(M+H)+]: 221, obsd. 221.2.

Workup

  1. temperaturethe resulting mixture was refluxed for 5 hours
  2. distillationMethanol was distilled off under reduced pressure
  3. additionthe residue was diluted with water (5 mL)
  4. extractionextracted with ethyl acetate (2×10 mL)
  5. washThe combined organic extracts were washed with water (5 mL)
  6. customdried
  7. concentrationconcentrated under reduced pressure
  8. customto obtain the crude product

Sources & evidence

ORD record
ord-0fb2539f5db947c0ad66af05fde2e389
Source dataset
uspto-grants-2014_04
Patent number
US08691993B2

Reaction notes

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