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

HRID 1764066Notes

Reaction equation

HRID 1764066 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 5 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 5 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-129f2194fb3845afae7f67a2d6263e74
Source dataset
uspto-grants-1978_09
Patent number
US04115101

Reaction notes

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