Hydrochloric Acid → 4'-(Benzyloxy)-5-hydroxy-3,3',7-trimethoxyflavone

HRID 223125Notes

Reaction equation

HRID 223125 reaction equation
[OH:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[C:4]([OH:10])[C:3]=1[C:11](=[O:15])[CH2:12][O:13][CH3:14].[CH2:16]([O:23][C:24]1[CH:32]=[CH:31][C:27]([C:28]([O-])=O)=[CH:26][C:25]=1[O:33][CH3:34])[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.[Na+].[OH-].[K+].Cl>C(O)C.C(Cl)(Cl)Cl>[CH2:16]([O:23][C:24]1[CH:32]=[CH:31][C:27]([C:28]2[O:1][C:2]3[C:3]([C:11](=[O:15])[C:12]=2[O:13][CH3:14])=[C:4]([OH:10])[CH:5]=[C:6]([O:8][CH3:9])[CH:7]=3)=[CH:26][C:25]=1[O:33][CH3:34])[C:17]1[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 14797Potassium HydroxideHCID 205225472',6'-Dihydroxy-2,4'-dimethoxyacetophenoneHCID 23702605Sodium 4-(benzyloxy)-3-methoxybenzoate

Product 1

HCID 205225384'-(Benzyloxy)-5-hydroxy-3,3',7-trimethoxyflavoneYield 62.7%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 6212ChloroformSolvent

Procedure

A mixture of 0.67 g of 2',6'-dihydroxy-2,4'-dimethoxyacetophenone, 3.5 g of bis-[4-(benzyloxy)-3-methoxybenzoic] anhydride and 1 g of sodium 4-(benzyloxy)-3-methoxybenzoate was heated at 180°-185° C. under reduced pressure for 3 hours. After cooling, 12 ml of 10% solution of potassium hydroxide in ethanol were added, and the mixture was refluxed under nitrogen for 30 minutes. To the cooled mixture were added 20 ml of 1 N-hydrochloric acid and 100 ml of chloroform, followed by shaking. The organic phase was separated and concentrated under reduced pressure. The residue was chromatographed on silica gel with chloroform. After recrystallization from ethyl acetate/hexane, there was obtained 0.86 g (60% yield) of 4'-(benzyloxy)-5-hydroxy-3,3',7-trimethoxyflavone as yellow crystals: m.p. 156°-157° C.

Workup

  1. temperaturewas heated at 180°-185° C. under reduced pressure for 3 hours
  2. temperatureAfter cooling
  3. temperaturethe mixture was refluxed under nitrogen for 30 minutes
  4. customThe organic phase was separated
  5. concentrationconcentrated under reduced pressure
  6. customThe residue was chromatographed on silica gel with chloroform
  7. customAfter recrystallization from ethyl acetate/hexane

Sources & evidence

ORD record
ord-cb01904e5f0d4d2db03f6503844c6b67
Source dataset
uspto-grants-1982_10
Patent number
US04352792

Reaction notes

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