Potassium Carbonate → 6-phenoxy-2-methyl-2H-1-benzopyran-3-carboxaldehyde

HRID 466181Notes

Reaction equation

HRID 466181 reaction equation
[O:1]([C:8]1[CH:15]=[C:12]([CH:13]=O)[C:11]([OH:16])=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH:17](=[O:21])/[CH:18]=[CH:19]/[CH3:20].C(=O)([O-])[O-].[K+].[K+]>O1CCOCC1.O>[O:1]([C:8]1[CH:9]=[CH:10][C:11]2[O:16][CH:19]([CH3:20])[C:18]([CH:17]=[O:21])=[CH:13][C:12]=2[CH:15]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 447466CrotonaldehydeHCID 149712582-Hydroxy-5-phenoxybenzaldehyde

Product 1

HCID 149713046-phenoxy-2-methyl-2H-1-benzopyran-3-carboxaldehyde

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

The starting material is prepared as follows: A mixture of 5-phenoxysalicylaldehyde (6.52 g, 30.4 mmol), crotonaldehyde (3.2 g, 45.7 mmol) and potassium carbonate (8.41 g, 60.9 mmol) in 100 ml of 1,4-dioxane is heated at reflux for 2 hours. The mixture is cooled, diluted with water, and extracted three times with dichloromethane. The combined organic layers are dried (MgSO4) and evaporated. Purification by flash chromatography (silica gel, 7% ethyl acetate/hexane) yields 6-phenoxy-2-methyl-2H-1-benzopyran-3-carboxaldehyde which is converted to 6-phenoxy-2-methyl-3-(N-hydroxyaminomethyl)-2H-1-benzopyran as described above.

Workup

  1. customThe starting material is prepared
  2. temperatureis heated
  3. temperatureat reflux for 2 hours
  4. temperatureThe mixture is cooled
  5. extractionextracted three times with dichloromethane
  6. dry with materialThe combined organic layers are dried (MgSO4)
  7. customevaporated
  8. customPurification by flash chromatography (silica gel, 7% ethyl acetate/hexane)

Sources & evidence

ORD record
ord-a9866c88e960461094f5407b9546e3f1
Source dataset
uspto-grants-1992_10
Patent number
US05155130

Reaction notes

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