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

HRID 2182029Notes

Reaction equation

HRID 2182029 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-7b07348a7ed74736bd82b8ff697e2b41
Source dataset
uspto-grants-2005_05
Patent number
US06894177B2

Reaction notes

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