Acetic Acid → Methyl 5-isopropyloxazole-4-carboxylate

HRID 485015Notes

Reaction equation

HRID 485015 reaction equation
C[O-].[Na+].[N+:4]([CH2:6][C:7]([O:9][CH3:10])=[O:8])#[C-:5].[C:11](Cl)(=[O:15])[CH:12]([CH3:14])[CH3:13].C(O)(=O)C>CN(C)C=O>[CH:12]([C:11]1[O:15][CH:5]=[N:4][C:6]=1[C:7]([O:9][CH3:10])=[O:8])([CH3:14])[CH3:13]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 62325Isobutyryl chlorideHCID 547815Methyl isocyanoacetateHCID 10942334Sodium Methoxide

Product 1

HCID 11446564Methyl 5-isopropyloxazole-4-carboxylateYield 70%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

13.7 g of sodium methoxide are dissolved in 200 ml of dimethylformamide, and 19.4 g of methyl α-isocyanoacetate are added dropwise thereto at -50° C. to -40° C. The mixture is stirred at the same temperature for 30 minutes. 25 g of isobutyryl chloride are gradually added to the mixture at -50° C. to -40° C., and said mixture is stirred at the same temperature for 2 hours. After the reaction, the mixture is adjusted to pH 3-4 with acetic acid and then condensed under reduced pressure to remove solvent. The residue is extracted with ethyl acetate and the extract is washed with aqueous sodium bicarbonate solution and water, successively. The extract is then dried and condensed under reduced pressure to remove solvent. 23.1 g of 5-isopropyl-4-methoxycarbonyloxazole are obtained. Yield: 70.0%.

Workup

  1. customat -50° C. to -40° C
  2. stirringis stirred at the same temperature for 2 hours
  3. customAfter the reaction
  4. customcondensed under reduced pressure
  5. customto remove solvent
  6. extractionThe residue is extracted with ethyl acetate
  7. washthe extract is washed with aqueous sodium bicarbonate solution and water
  8. customThe extract is then dried
  9. customcondensed under reduced pressure
  10. customto remove solvent

Sources & evidence

ORD record
ord-669cf125f473451cbc590b5bedfcf93c
Source dataset
uspto-grants-1985_08
Patent number
US04535089

Reaction notes

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