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

HRID 1493352Notes

Reaction equation

HRID 1493352 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].[K].S(OC)(O[CH3:18])(=O)=O>CC(C)=O>[CH3:7][C:6]1[C:2]([O:1][CH3:18])=[C:3]([C:9]([O:11][CH3:12])=[O:10])[S:4][C:5]=1[CH3:8]

Participants

5

Reactant 3

HCID 6497Dimethyl SulfateHCID 5462222PotassiumHCID 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 carbonte (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-06ce5a78e9424b40aa9393fab3179dce
Source dataset
uspto-grants-1991_06
Patent number
US05021449

Reaction notes

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