Potassium Carbonate → 6-(3-phenylpropyloxy)-2H-1-benzopyran-3-carboxaldehyde

HRID 466179Notes

Reaction equation

HRID 466179 reaction equation
[OH:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH2:9][C:8]([CH:11]=[O:12])=[CH:7][C:6]=2[CH:13]=1.C(=O)([O-])[O-].[K+].[K+].Br[CH2:21][CH2:22][CH2:23][C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1>CN(C=O)C>[C:24]1([CH2:23][CH2:22][CH2:21][O:1][C:2]2[CH:3]=[CH:4][C:5]3[O:10][CH2:9][C:8]([CH:11]=[O:12])=[CH:7][C:6]=3[CH:13]=2)[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 12503(3-Bromopropyl)benzeneHCID 47708156-Hydroxychromene-3-carboxaldehyde

Product 1

HCID 149712646-(3-phenylpropyloxy)-2H-1-benzopyran-3-carboxaldehyde

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

The starting material is prepared as follows: A solution of 6-hydroxy-2H-1-benzopyran-3-carboxaldehyde (5.0 g, 28.4 mmol) in 100 ml of DMF is treated with potassium carbonate (7.85 g, 56.8 mmol) and 1-bromo-3-phenylpropane (6.22 g, 31.2 mmol). The reaction mixture is stirred for 2 days at room temperature. This is partitioned between water and dichloromethane and the aqueous layer is extracted twice with dichloromethane. The combined organic layer is dried (MgSO4), and evaporated. The residue is chromatographed (silica gel, 20% ethyl acetate/hexane) to afford 6-(3-phenylpropyloxy)-2H-1-benzopyran-3-carboxaldehyde, m.p. 71°-73° C., as an oil which crystallizes on standing. The aldehyde is converted to 3-(N-hydroxyaminomethyl)-6-(3-phenylpropyloxy)-2H-1-benzopyran as described above.

Workup

  1. customThe starting material is prepared
  2. customThis is partitioned between water and dichloromethane
  3. extractionthe aqueous layer is extracted twice with dichloromethane
  4. dry with materialThe combined organic layer is dried (MgSO4)
  5. customevaporated
  6. customThe residue is chromatographed (silica gel, 20% ethyl acetate/hexane)

Sources & evidence

ORD record
ord-47bed8441d294677ad66c25791b2b4c5
Source dataset
uspto-grants-1992_10
Patent number
US05155130

Reaction notes

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