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

HRID 2110960Notes

Reaction equation

HRID 2110960 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-6b634234f3894f728ea5032e7f89ff72
Source dataset
uspto-grants-2009_04
Patent number
US07517992B2

Reaction notes

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