Water → 1-(3,4-dihydro-2H-1-benzopyran-6-yl)-4,4,4-trifluorobutane-1,3-dione

HRID 591075Notes

Reaction equation

HRID 591075 reaction equation
[O:1]1[C:6]2[CH:7]=[CH:8][C:9]([C:11](=[O:13])[CH3:12])=[CH:10][C:5]=2[CH2:4][CH2:3][CH2:2]1.[H-].[Na+].[F:16][C:17]([F:24])([F:23])[C:18](OCC)=[O:19].O>O1CCCC1>[O:1]1[C:6]2[CH:7]=[CH:8][C:9]([C:11](=[O:13])[CH2:12][C:18](=[O:19])[C:17]([F:24])([F:23])[F:16])=[CH:10][C:5]=2[CH2:4][CH2:3][CH2:2]1

Participants

6

Reactant 4

HCID 962WaterHCID 9794Ethyl trifluoroacetateHCID 24758Sodium hydrideHCID 123570181-(3,4-dihydro-2H-1-benzopyran-6-yl)ethan-1-one

Product 1

HCID 708188081-(3,4-dihydro-2H-1-benzopyran-6-yl)-4,4,4-trifluorobutane-1,3-dioneYield 100%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Under a nitrogen atmosphere, 1-(3,4-dihydro-2H-1-benzopyran-6-yl)ethan-1-one (49a) (1.55 g, 8.8 mmol) was dissolved in anhydrous tetrahydrofuran (48 mL) and sodium hydride (60% in mineral oil, 0.42 g, 10.6 mmol) was added portionwise, maintaining the temperature between −5 and 0° C. After 30 minutes stirring at the same temperature, ethyl trifluoroacetate (1.5 mL, 10.6 mmol) was added and the reaction mixture was stirred at room temperature for 3 hours. Water (10 mL) was added and tetrahydrofuran was removed in vacuo. The resulting aqueous layer was extracted with ethyl acetate (2×20 mL). The organic layer was washed with brine (10 mL), dried over sodium sulfate and concentrated in vacuo to provide 1-(3,4-dihydro-2H-1-benzopyran-6-yl)-4,4,4-trifluorobutane-1,3-dione (49b) (2.39 g, 8.8 mmol, 100%) which was used without further purification.

Workup

  1. temperaturemaintaining the temperature between −5 and 0° C
  2. additionwas added
  3. customtetrahydrofuran was removed in vacuo
  4. extractionThe resulting aqueous layer was extracted with ethyl acetate (2×20 mL)
  5. washThe organic layer was washed with brine (10 mL)
  6. dry with materialdried over sodium sulfate
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-16579ed218e14652bae456fb1868ced8
Source dataset
uspto-grants-2016_01
Patent number
US09238026B2

Reaction notes

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