Kojic Acid → 4H-Pyran-4-one, 2-(hydroxymethyl)-5-propoxy-

HRID 2236536Notes

Reaction equation

HRID 2236536 reaction equation
[CH:1]1[C:6](=[O:7])[C:5]([OH:8])=[CH:4][O:3][C:2]=1[CH2:9][OH:10].C(=O)([O-])[O-].[K+].[K+].[I-].[K+].Br[CH2:20][CH2:21][CH3:22]>CN(C)C=O>[OH:10][CH2:9][C:2]1[O:3][CH:4]=[C:5]([O:8][CH2:20][CH2:21][CH3:22])[C:6](=[O:7])[CH:1]=1

Participants

6

Reactant 4

HCID 3840Kojic AcidHCID 4875Potassium IodideHCID 78401-BromopropaneHCID 11430Potassium Carbonate

Product 1

HCID 426257524H-Pyran-4-one, 2-(hydroxymethyl)-5-propoxy-

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A mixture of kojic acid (28.4 g, 0.20 mole), 120 mL of N,N-dimethylformamide, potassium carbonate powder (27.6 g, 0.20 mole), potassium iodide (1.66 g, 0.01 mole), and 1-bromopropane (24.6 g, 0.20 mole) is stirred for 15 minutes at ambient temperature then stirred at 90° C. for 3 hours. The reaction mixture is cooled, evaporated to dryness in vacuo and then portioned between water and chloroform. The aqueous layer is extracted with chloroform (3×100 mL) and ethyl acetate (6×100 mL). The combined organics were dried with sodium sulfate and passed through a pad of magnesol and silica gel eluting with ethyl acetate. The eluate is evaporated in vacuo and crystallized with hexane/ethyl acetate (2/1) to give an off-white solid, 22.60 g, (61%); MS (ES+): m/z 185.3 (M+H).

Workup

  1. stirringthen stirred at 90° C. for 3 hours
  2. temperatureThe reaction mixture is cooled
  3. customevaporated to dryness in vacuo
  4. extractionThe aqueous layer is extracted with chloroform (3×100 mL) and ethyl acetate (6×100 mL)
  5. dry with materialThe combined organics were dried with sodium sulfate
  6. customThe eluate is evaporated in vacuo
  7. customcrystallized with hexane/ethyl acetate (2/1)
  8. customto give an off-white solid, 22.60 g, (61%)

Sources & evidence

ORD record
ord-f41b7e91bb884d0cb11e62ea57b5f117
Source dataset
uspto-grants-2010_05
Patent number
US07713994B2

Reaction notes

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