Sodium borohydride → 7-Fluorochroman-4-ol

HRID 2238580Notes

Reaction equation

HRID 2238580 reaction equation
[F:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH2:7][CH2:8][O:9]2)=[CH:4][CH:3]=1.[BH4-].[Na+]>CO>[F:1][C:2]1[CH:11]=[C:10]2[C:5]([CH:6]([OH:12])[CH2:7][CH2:8][O:9]2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 146531327-fluoro-3,4-dihydro-2H-1-benzopyran-4-one

Product 1

HCID 224047977-Fluorochroman-4-olYield 74.3%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of 7-fluoro-2,3-dihydro-4H-chromen-4-one (6.25 g, 37.6 mmol, US 20050038032) in methanol (60 mL) was added sodium borohydride (1.57 g, 41.4 mmol) at 0° C. The reaction mixture was stirred at the same temperature for 1 hour, and evaporated to remove methanol. The residue was quenched with water, and extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate, and concentrated in vacuum. The residue was purified by column chromatography on silica gel (hexane:ethyl acetate=3:1 as an eluent) to afford the title compound as a pale gray solid (4.70 g, 74%):

Workup

  1. customevaporated
  2. customto remove methanol
  3. customThe residue was quenched with water
  4. extractionextracted with ethyl acetate
  5. washThe extract was washed with brine
  6. dry with materialdried over magnesium sulfate
  7. concentrationconcentrated in vacuum
  8. customThe residue was purified by column chromatography on silica gel (hexane

Sources & evidence

ORD record
ord-5c05da46632e453d8ada9556f322419b
Source dataset
uspto-grants-2010_05
Patent number
US07718809B2

Reaction notes

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