Dimethyl Sulfate → 6-ETHYL-4-METHOXY-2-PYRANONE

HRID 1360340Notes

Reaction equation

HRID 1360340 reaction equation
[CH2:1]([C:3]1[O:8][C:7](=[O:9])[CH:6]=[C:5]([OH:10])[CH:4]=1)[CH3:2].[C:11](=O)([O-])[O-].[K+].[K+].COS(OC)(=O)=O>>[CH2:1]([C:3]1[O:8][C:7](=[O:9])[CH:6]=[C:5]([O:10][CH3:11])[CH:4]=1)[CH3:2]

Participants

4

Reactant 3

HCID 6497Dimethyl SulfateHCID 11430Potassium CarbonateHCID 547135586-Ethyl-4-hydroxy-2H-pyran-2-one

Product 1

HCID 111162626-ETHYL-4-METHOXY-2-PYRANONEYield 64%

Procedure

The following is based on the procedure disclosed in Deshpande, V. H. et al. Indian Journal of Chemistry, 35, pp. 790-793 (1996). Compound V (57.65 g, 411 mmol) was placed in an oven dried 2000 mL three-neck flask and dissolved in dry acetone (1500 ml). To this solution was added potassium carbonate (74 g, 540 mmoles) and dimethylsulfate (51 ml, 540 mmoles). The flask was equipped with a water condenser and mechanical stirrer. The mixture was heated to reflux for 3.5 hours. Analysis by LCMS showed reaction to be complete. Therefore the reaction was cooled to room temperature and the solids removed by filtration. The solvent of the filtrate was removed by rotary evaporation. The yellow oily residue left behind was purified by silica gel chromatography eluting with a gradient of 10% to 50% ethyl acetate in hexanes. The appropriate fractions were collected and concentrated by rotary evaporation to yield compound W (40.55 g, 61%) as a yellow solid. 1H NMR CDCl3 δ: 5.78 (s, 1H), 5.42 (s, 1H), 3.80 (s, 3H), 2.51 (q, 2H, J=8.0 Hz), 1.22 (t, 3H, J=8.0 Hz). ESMS m/z: 155 [M+H+].

Workup

  1. customdried 2000 mL three-neck flask
  2. dissolutiondissolved in dry acetone (1500 ml)
  3. customThe flask was equipped with a water condenser and mechanical stirrer
  4. temperatureThe mixture was heated
  5. temperatureto reflux for 3.5 hours
  6. customreaction
  7. customthe solids removed by filtration
  8. customThe solvent of the filtrate was removed by rotary evaporation
  9. waitThe yellow oily residue left
  10. custombehind was purified by silica gel chromatography
  11. washeluting with a gradient of 10% to 50% ethyl acetate in hexanes
  12. customThe appropriate fractions were collected
  13. concentrationconcentrated by rotary evaporation

Sources & evidence

ORD record
ord-5de83dad7c464530b69c0f85f6813f63
Source dataset
uspto-grants-2011_02
Patent number
US07879846B2

Reaction notes

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