Phosphorus oxychloride → 5-Methyl-2-styryl-4-oxazoleacetic acid

HRID 746027Notes

Reaction equation

HRID 746027 reaction equation
[C:1]([NH:11][CH:12]([C:18](=[O:20])[CH3:19])[CH2:13][C:14]([O:16]C)=[O:15])(=O)[CH:2]=[CH:3][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.P(Cl)(Cl)(Cl)=O>C1(C)C=CC=CC=1>[CH3:19][C:18]1[O:20][C:1]([CH:2]=[CH:3][C:4]2[CH:5]=[CH:6][CH:7]=[CH:8][CH:9]=2)=[N:11][C:12]=1[CH2:13][C:14]([OH:16])=[O:15]

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 54555293HCID 54555293, compound

Product 1

HCID 539803785-Methyl-2-styryl-4-oxazoleacetic acid

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of methyl 3-cinnamoylamino-4-oxovalerate (2.2 g), phosphorus oxychloride (2.2 ml) and toluene (24 ml) was refluxed with stirring for an hour. The solvent was distilled off and the residue was neutralized with aqueous sodium hydrogen carbonate and extracted with ethyl ether. The ethyl ether layer was washed with water and dried over anhydrous magnesium sulfate. The solvent was then distilled off and ethanol (8 ml) and 2N sodium hydroxide (8 ml) were added to the residue. The mixture was stirred for 30 minutes and adjusted to pH 2 with diluted hydrochloric acid. The resulting crystalline precipitate was collected by filtration to give 5-methyl-2-styryl-4-oxazoleacetic acid; yield 1.50 g (77.3%). Recrystallization from ethanol gave pale brown needles melting at 182°-183° C. The IR and NMR spectra of this product were in good agreement with those of the compound obtained in Example 1.

Workup

  1. temperaturewas refluxed
  2. distillationThe solvent was distilled off
  3. extractionextracted with ethyl ether
  4. washThe ethyl ether layer was washed with water
  5. dry with materialdried over anhydrous magnesium sulfate
  6. distillationThe solvent was then distilled off
  7. additionethanol (8 ml) and 2N sodium hydroxide (8 ml) were added to the residue
  8. stirringThe mixture was stirred for 30 minutes
  9. filtrationThe resulting crystalline precipitate was collected by filtration

Sources & evidence

ORD record
ord-f304703337b545c4b5cc017383df7962
Source dataset
uspto-grants-1986_07
Patent number
US04602027

Reaction notes

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