Dimethyl Sulfate → 6-Hydroxy-3-methoxyxanthone

HRID 54716

Reaction equation

HRID 54716 reaction equation
[OH:1][C:2]1[CH:3]=[CH:4][C:5]2[C:6](=[O:17])[C:7]3[C:12]([O:13][C:14]=2[CH:15]=1)=[CH:11][C:10]([OH:16])=[CH:9][CH:8]=3.[CH3:18]OS(OC)(=O)=O>O.C(O)C>[OH:16][C:10]1[CH:11]=[C:12]2[C:7](=[CH:8][CH:9]=1)[C:6](=[O:17])[C:5]1[CH:4]=[CH:3][C:2]([O:1][CH3:18])=[CH:15][C:14]=1[O:13]2

Participants

5

Reactant 2

HCID 6497Dimethyl SulfateHCID 57493223,6-dihydroxy-9H-xanthen-9-one

Product 1

HCID 124481156-Hydroxy-3-methoxyxanthoneYield 50%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

7.0 g (30.7 mmol) of 3,6-dihydroxyxanthone is dissolved in aq. NAOH (2.5 g(62.5 mmol) in 200 mls H2O). 3.2 mls (33.6 mmol) of dimethylsulfate is added dropwise with stirring, and solid forms immediately upon completion. Stirred further 1 hour and heated to reflux for 15 minutes. Additional base is added to insure complete solubility of phenols. The solution is acidified with HCl, and filtration yields a mixture of staring material and the target compound. Solid is heated to reflux in about 200 mls ethanol for 15 minutes to dissolve starting material, and solid is filtered out, washing with ethanol and water. This may have to be repeated several times to obtain pure compound in about 50% yield; mp=303-306-C.NMR (200 MHZ in d-DMSO) s 3.89 (3H,s), 6.82 (1H,d,J=2.24 Hz), 6.87 (1H,m), 6.99 (1H,dd,J=8.78 Hz, 2.20 Hz),, 7.09 (1H,d,J=2.26 Hz), 7.99 (1H,d,J=8.52 Hz), 8.03 (1H,d,J=8.78 Hz).

Workup

  1. stirringStirred further 1 hour
  2. temperatureheated
  3. temperatureto reflux for 15 minutes
  4. additionAdditional base is added
  5. filtrationThe solution is acidified with HCl, and filtration
  6. customyields
  7. additiona mixture of staring material
  8. temperatureSolid is heated
  9. dissolutionto dissolve
  10. filtrationis filtered out
  11. washwashing with ethanol and water
  12. customto obtain pure compound in about 50% yield

Sources & evidence

ORD record
ord-1fdcae12e7774ab787556433cfe0b506
Source dataset
uspto-grants-1997_04
Patent number
US05623080

Linked notes

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