Sulfuric Acid → Methyl [5-methyl-2-(4-methylphenyl)-1,3-oxazol-4-YL]acetate

HRID 46022Notes

Reaction equation

HRID 46022 reaction equation
[CH3:1][C:2]1[CH:19]=[CH:18][C:5]([C:6]([NH:8][CH:9]([C:15](=[O:17])[CH3:16])[CH2:10][C:11]([O:13][CH3:14])=[O:12])=O)=[CH:4][CH:3]=1.OS(O)(=O)=O>C(OC(=O)C)(=O)C>[CH3:14][O:13][C:11](=[O:12])[CH2:10][C:9]1[N:8]=[C:6]([C:5]2[CH:18]=[CH:19][C:2]([CH3:1])=[CH:3][CH:4]=2)[O:17][C:15]=1[CH3:16]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 10220905Methyl 3-(4-methylbenzamido)-4-oxopentanoate

Product 1

HCID 10490570Methyl [5-methyl-2-(4-methylphenyl)-1,3-oxazol-4-YL]acetateYield 87%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

The intermediate prepared in Example 8 (280 g, 1.06 mol) was dissolved in acetic anhydride (650 mL) followed by slow addition of conc. H2SO4 (60 ml). The pot temperature reached 80° C. The reaction was then held at 85° C. for 1 hour, cooled, and the acetic anhydride removed in vacuo. The residue was poured into ice water (2 L) and extracted with EtOAc (4 L total). The organic layer was then stirred with 1 N NaOH (500 mL) for 1 hour, separated, then dried with MgSO4 and concentrated to afford the title ester as a clear oil (223 g, 87%), which slowly solidified to a white solid.

Workup

  1. customreached 80° C
  2. temperaturecooled
  3. customthe acetic anhydride removed in vacuo
  4. additionThe residue was poured into ice water (2 L)
  5. extractionextracted with EtOAc (4 L total)
  6. customseparated
  7. dry with materialdried with MgSO4
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-5469fedc590b45558d54bc28eed6400c
Source dataset
uspto-grants-2013_09
Patent number
US08541618B2

Reaction notes

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