Sodium Hydroxide → 8-fluoro-2H-chromene-5-carboxylic acid

HRID 1531432Notes

Reaction equation

HRID 1531432 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]([C:12]([O:14]C)=[O:13])=[C:6]2[C:11]=1[O:10][CH2:9][CH:8]=[CH:7]2.[OH-].[Na+]>C(O)C.O>[F:1][C:2]1[CH:3]=[CH:4][C:5]([C:12]([OH:14])=[O:13])=[C:6]2[C:11]=1[O:10][CH2:9][CH:8]=[CH:7]2

Participants

5

Reactant 2

HCID 14798Sodium HydroxideHCID 12016893Methyl 8-fluoro-2H-1-benzopyran-5-carboxylate

Product 1

HCID 120168948-fluoro-2H-chromene-5-carboxylic acid

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

Methyl 8-fluoro-2H-1-benzopyran-5-carboxylate (7.36 g, 35.4 mmol) was dissolved in absolute ethanol (220 mL), NaOH (2.0 g, 49.6 mmol) in H2O (25 mL), was added thereto, and the reaction mixture was refluxed for 1.5 hour. The reaction mixture was cooled and the solvent was removed in vacuo. The yellow solid was dissolved in H2O (150 mL), active charcoal was added and then filtered off. The resulting light-coloured liquid was washed with diethyl ether, the aqueous solution was made acidic with 2 M HCl and the product was extracted twice with ethyl acetate. The combined organic portions were treated with brine, dried with MgSO4, filtered, and the solvent was removed in vacuo to give 6.64 g (97% yield) of a yellowish solid (dried in a desiccator over P2O5) as the title compound (mp 224-226° C.). EIMS (70 eV) m/z (relative intensity) 194 (93, M+), 193 (100), 149 (56), 148 (68), 120 (13), 88 (25), 75 (28), 74 (21), 60 (12).

Workup

  1. temperaturethe reaction mixture was refluxed for 1.5 hour
  2. temperatureThe reaction mixture was cooled
  3. customthe solvent was removed in vacuo
  4. dissolutionThe yellow solid was dissolved in H2O (150 mL)
  5. additionactive charcoal was added
  6. filtrationfiltered off
  7. washThe resulting light-coloured liquid was washed with diethyl ether
  8. extractionthe product was extracted twice with ethyl acetate
  9. additionThe combined organic portions were treated with brine
  10. dry with materialdried with MgSO4
  11. filtrationfiltered
  12. customthe solvent was removed in vacuo

Sources & evidence

ORD record
ord-cda3ac20f3a54a9a94e07f52f709dd8a
Source dataset
uspto-grants-2001_03
Patent number
US06197978B1

Reaction notes

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