1,8-Diazabicyclo(5.4.0)undec-7-ene → 5-fluoro-8-methoxy-2H-chromene

HRID 2084326Notes

Reaction equation

HRID 2084326 reaction equation
[F:1][C:2]1[C:7]([CH:8]=O)=[C:6]([OH:10])[C:5]([O:11][CH3:12])=[CH:4][CH:3]=1.[CH2:13]1CCN2C(=NCCC2)C[CH2:14]1.[Br-].C(P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)=C>C(#N)C.O>[F:1][C:2]1[CH:3]=[CH:4][C:5]([O:11][CH3:12])=[C:6]2[C:7]=1[CH:8]=[CH:13][CH2:14][O:10]2

Participants

6

Reactant 3

HCID 811841,8-Diazabicyclo(5.4.0)undec-7-eneHCID 224828186-Fluoro-2-hydroxy-3-methoxybenzaldehydeHCID 178477248HCID 178477248, compound

Product 1

HCID 224828455-fluoro-8-methoxy-2H-chromeneYield 35.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6342AcetonitrileSolvent

Procedure

6-Fluoro-2-hydroxy-3-methoxy-benzaldehyde (3.32 g, 19 mmol) was dissolved in acetonitrile (20 ml) and DBU (2.97 ml, 19 mmol) was added followed by vinyltriphenylphosphine bromide (7.2 g, 19 mmol). The reaction mixture was heated under reflux for 48 h, diluted with water and extracted with ether (3×50 ml). The organic phase was washed with water, 10% sodium hydroxide, water and brine and evaporated in vacuo. The residue was submitted to column chromatography (silica gel, EA:Hex, 1:20) yielding 1.2 g of 5-fluoro-8-methoxy-2H-chromene (34%).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureunder reflux for 48 h
  3. extractionextracted with ether (3×50 ml)
  4. washThe organic phase was washed with water, 10% sodium hydroxide, water and brine
  5. customevaporated in vacuo

Sources & evidence

ORD record
ord-e0fbfc54601f4dcd966b2e56fe798ee0
Source dataset
uspto-grants-2004_04
Patent number
US06716850B2

Reaction notes

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