Hydrochloric Acid → 8-Fluoro-2,3-dihydro-4H-1-benzopyran-4-one

HRID 1887429Notes

Reaction equation

HRID 1887429 reaction equation
CC(C)([O-])C.[K+].[F:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1[OH:14].[C:15]1(=O)[O:18][CH2:17][CH2:16]1.Cl>O1CCCC1>[F:7][C:8]1[CH:13]=[CH:12][CH:11]=[C:10]2[C:9]=1[O:14][CH2:15][CH2:16][C:17]2=[O:18]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 2365Beta-PropiolactoneHCID 97072-FluorophenolHCID 23665647Potassium tert-butoxide

Product 1

HCID 139538178-Fluoro-2,3-dihydro-4H-1-benzopyran-4-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Potassium t-butoxide (2.42 g) was added to a solution of the compound 1-1 (2.20 g) in tetrahydrofuran (100 ml) at room temperature. After stirring for five minutes at the same temperature, beta-propiolactone (2.71 ml) was added. Because of heat generation, the mixture was moved to an ice bath and stirred at the same temperature for one hour. After further stirring at room temperature for four hours, the mixture was made acidic with 1 N hydrochloric acid to terminate the reaction. The aqueous layer was extracted with ethyl acetate, and the organic layer was washed with brine. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was crystallized by adding a mixed solvent of 20% ethyl acetate-hexane to obtain the title compound (1.44 g).

Workup

  1. additionwas added
  2. customBecause of heat generation, the mixture was moved to an ice bath
  3. stirringAfter further stirring at room temperature for four hours
  4. customto terminate
  5. customthe reaction
  6. extractionThe aqueous layer was extracted with ethyl acetate
  7. washthe organic layer was washed with brine
  8. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  9. customthe solvent was evaporated under reduced pressure
  10. customThe residue was crystallized
  11. additionby adding a mixed solvent of 20% ethyl acetate-hexane

Sources & evidence

ORD record
ord-0c435965d8f34caca74e059ed7f04e33
Source dataset
uspto-grants-2013_08
Patent number
US08501733B2

Reaction notes

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