Dimethyl Sulfate → Methyl 3-methoxy-4,5-dimethyl-2-thiophenecarboxylate

HRID 1200107Notes

Reaction equation

HRID 1200107 reaction equation
[OH:1][C:2]1[C:6]([CH3:7])=[C:5]([CH3:8])[S:4][C:3]=1[C:9]([O:11][CH3:12])=[O:10].[C:13](=O)([O-])[O-].[K+].[K+].S(OC)(OC)(=O)=O>CC(C)=O>[CH3:7][C:6]1[C:2]([O:1][CH3:13])=[C:3]([C:9]([O:11][CH3:12])=[O:10])[S:4][C:5]=1[CH3:8]

Participants

5

Reactant 3

HCID 6497Dimethyl SulfateHCID 11430Potassium CarbonateHCID 54691275Methyl 3-hydroxy-4,5-dimethylthiophene-2-carboxylate

Product 1

HCID 14154178Methyl 3-methoxy-4,5-dimethyl-2-thiophenecarboxylate

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a solution of methyl 3-hydroxy-4,5-dimethylthiophene-2-carboxylate (Preparation 1) (29.7 g, 160 mmol) in anhydrous acetone (500 ml) was added anhydrous potassium carbonate (24.5 g, 178 mmol) and the mixture stirred for 1 hour at room temperature. Dimethyl sulphate (22.4 g, 178 mmol) was added and the mixture stirred under reflux for 2.5 hours. The solvent was evaporated under reduced pressure and the residue partitioned between water and ethyl acetate. The organic phase was washed with brine, dried with sodium sulphate and evaporated to give crude product which was used in the following preparation.

Workup

  1. stirringthe mixture stirred
  2. temperatureunder reflux for 2.5 hours
  3. customThe solvent was evaporated under reduced pressure
  4. customthe residue partitioned between water and ethyl acetate
  5. washThe organic phase was washed with brine
  6. dry with materialdried with sodium sulphate
  7. customevaporated
  8. customto give crude product which
  9. customwas used in the following preparation

Sources & evidence

ORD record
ord-64b06fe4eda047cea9e01785b51b3cd4
Source dataset
uspto-grants-1990_02
Patent number
US04904686

Reaction notes

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