Acrolein → 2H-1-Benzopyran-3-carboxaldehyde, 6-methoxy-

HRID 466172Notes

Reaction equation

HRID 466172 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]([OH:11])=[C:7]([CH:10]=1)[CH:8]=O.C(=O)([O-])[O-].[K+].[K+].[CH:18]([CH:20]=[CH2:21])=[O:19]>O1CCOCC1.O>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][C:6]2[O:11][CH2:21][C:20]([CH:18]=[O:19])=[CH:8][C:7]=2[CH:10]=1

Participants

6

Reactant 3

HCID 7847AcroleinHCID 11430Potassium CarbonateHCID 956952-Hydroxy-5-methoxybenzaldehyde

Product 1

HCID 424302H-1-Benzopyran-3-carboxaldehyde, 6-methoxy-

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
100 °C

Procedure

The starting material is prepared as follows: 5-Methoxy-2-hydroxybenzaldehyde (25 g, 0.16 mol) and potassium carbonate (22.7 g, 0.16 mol) are taken up in 300 ml of 1,4-dioxane and treated with acrolein (13.8 g, 0.25 mol). The mixture is heated at 100° C. for 1 hour, and allowed to cool. The mixture is diluted with water and extracted three times with ether. The combined ether extracts are dried (MgSO4) and evaporated. The residual oil is dissolved in a minimal amount of ethyl acetate (approx. 40 ml) and passed through 40 g of silica gel. The gel is successively washed with several portions of a hexane/ether mixture (3:1) until no further fluorescent material is eluted. The organic phase is evaporated and the residue is crystallized from ethyl acetate/hexane to give 6-methoxy-2H-1-benzopyran-3-carboxaldehyde as a yellow solid, m.p. 49°-50° C.

Workup

  1. customThe starting material is prepared
  2. temperatureto cool
  3. extractionextracted three times with ether
  4. dry with materialThe combined ether extracts are dried (MgSO4)
  5. customevaporated
  6. dissolutionThe residual oil is dissolved in a minimal amount of ethyl acetate (approx. 40 ml)
  7. washThe gel is successively washed with several portions of a hexane/ether mixture (3:1) until no further fluorescent material
  8. washis eluted
  9. customThe organic phase is evaporated
  10. customthe residue is crystallized from ethyl acetate/hexane

Sources & evidence

ORD record
ord-487c220d194143a7ac3fa2ff7e8d3655
Source dataset
uspto-grants-1992_10
Patent number
US05155130

Reaction notes

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