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

HRID 606337Notes

Reaction equation

HRID 606337 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-aaac8a912ea64d06b08d46e7e027e377
Source dataset
uspto-grants-2011_03
Patent number
US07915295B2

Reaction notes

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