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

HRID 751555Notes

Reaction equation

HRID 751555 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-1c9dc8d7bfb84757baf8de51ec6d1e22
Source dataset
uspto-grants-2008_07
Patent number
US07405310B2

Reaction notes

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