Methanol → 4H-Pyran-3-carboxylic acid, 2,6-dimethyl-4-oxo-, methyl ester

HRID 2072294Notes

Reaction equation

HRID 2072294 reaction equation
[C:1]([C:4]1[C:9](=[O:10])[CH:8]=[C:7]([CH3:11])[O:6][C:5]=1[CH3:12])([OH:3])=[O:2].[C:13](Cl)(=O)C.CO.C(=O)([O-])[O-].[Na+].[Na+]>C(Cl)Cl>[C:1]([C:4]1[C:9](=[O:10])[CH:8]=[C:7]([CH3:11])[O:6][C:5]=1[CH3:12])([O:3][CH3:13])=[O:2]

Participants

6

Reactant 4

HCID 887MethanolHCID 6367Acetyl chlorideHCID 10340Sodium CarbonateHCID 2011052,6-Dimethyl-4-oxo-4H-pyran-3-carboxylic acid

Product 1

HCID 122813714H-Pyran-3-carboxylic acid, 2,6-dimethyl-4-oxo-, methyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

42 g of 3-carboxy-2,6-dimethylpyr-4-one is dissolved in 250 ml of methylene chloride. In a second flask, 20 ml of acetyl chloride is cautiously added to 400 ml of methanol. The two solutions are mixed and refluxed for five hours. Solid sodium carbonate is added and the solvent removed after a water wash. The residue is distilled (115°-125° at 0.1 mm) to give 40 g of 3-carbomethoxy-2,6-dimethylpyr-4-one as a waxy solid.

Workup

  1. additionThe two solutions are mixed
  2. temperaturerefluxed for five hours
  3. customthe solvent removed after a water
  4. washwash
  5. distillationThe residue is distilled (115°-125° at 0.1 mm)

Sources & evidence

ORD record
ord-5d18beedd07a42abb6f9921a2a369e22
Source dataset
uspto-grants-1977_09
Patent number
US04051142

Reaction notes

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