Hydrochloric Acid → Dimethyl 2-methyl-3-hydroxy-6-vinylpyridine 4,5-dicarboxylate

HRID 614404Notes

Reaction equation

HRID 614404 reaction equation
[C:1]([O:9][CH3:10])(=[O:8])/[CH:2]=[CH:3]\[C:4]([O:6][CH3:7])=[O:5].C([O:13][C:14]1O[C:17]([CH:19]=[CH2:20])=[N:16][C:15]=1[CH3:21])C.Cl.C(=O)(O)[O-].[Na+]>CO.O.CCOCC>[CH3:21][C:15]1[C:14]([OH:13])=[C:3]([C:4]([O:6][CH3:7])=[O:5])[C:2]([C:1]([O:9][CH3:10])=[O:8])=[C:17]([CH:19]=[CH2:20])[N:16]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 516892Sodium BicarbonateHCID 5271565Dimethyl maleateHCID 202639815-Ethoxy-4-methyl-2-vinyloxazole

Product 1

HCID 20263984Dimethyl 2-methyl-3-hydroxy-6-vinylpyridine 4,5-dicarboxylate

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Procedure

A mixture of 0.2 mole of dimethyl maleate and 0.1 mole of 5-ethoxy-4-methyl-2-vinyloxazole are heated at 110°-115° C. for 4 hours. The reaction mixture is cooled and 20 ml. of a 25% solution of hydrogen chloride (dry) in absolute methanol added. Addition of ether to the cooled reaction mixture precipitates the hydrochloride salt of the product. The free base is obtained by dissolving the hydrochloride salt in a minimum volume of water, adding solid sodium bicarbonate to pH 6.5 to 7.0 and extracting with chloroform. The combined chloroform extracts are dried over sodium sulfate and concentrated in vacuo to give dimethyl 2-methyl-3-hydroxy-6-vinyl-pyridine 4,5-dicarboxylate.

Workup

  1. temperatureare heated at 110°-115° C. for 4 hours
  2. temperatureThe reaction mixture is cooled
  3. customto the cooled reaction mixture
  4. customprecipitates the hydrochloride salt of the product
  5. customThe free base is obtained
  6. extractionextracting with chloroform
  7. dry with materialThe combined chloroform extracts are dried over sodium sulfate
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-121ed28e2b3c44799df1d883d8a02c04
Source dataset
uspto-grants-1979_03
Patent number
US04144342

Reaction notes

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