Hydroxyamine hydrochloride → Ethyl 5-(4-tert-butylphenyl)-1,2-oxazole-3-carboxylate

HRID 1510459Notes

Reaction equation

HRID 1510459 reaction equation
Cl.[NH2:2]O.[C:4]([C:8]1[CH:13]=[CH:12][C:11]([C:14](=[O:23])[CH2:15][C:16](=O)[C:17]([O:19][CH2:20][CH3:21])=[O:18])=[CH:10][CH:9]=1)([CH3:7])([CH3:6])[CH3:5]>C(O)C>[C:4]([C:8]1[CH:13]=[CH:12][C:11]([C:14]2[O:23][N:2]=[C:16]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH:15]=2)=[CH:10][CH:9]=1)([CH3:7])([CH3:6])[CH3:5]

Participants

4

Reactant 2

HCID 443297Hydroxyamine hydrochlorideHCID 43186901Ethyl 4-(4-tert-butylphenyl)-2,4-dioxobutanoate

Product 1

HCID 20534825Ethyl 5-(4-tert-butylphenyl)-1,2-oxazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Hydroxylamine hydrochloride (6.14 g, 88.0 mmol) was added to a suspension of ethyl 4-(4-tert-butylphenyl)-2,4-dioxobutanoate (20.4 g, 73.7 mmol) in absolute ethanol (300 mL) and the reaction was heated to reflux for 3 hours. After cooling to room temperature, the organics were removed in vacuo and the resulting residue was purified by silica gel chromatography, eluting with heptane to 10% methanol in dichloromethane, to obtain afford the title compound white solid was filtered, washed with water and cold ethanol and dried in vacuo to obtain ethyl 5-(4-tert-butylphenyl)isoxazole-3-carboxylate (15.9 g, 58.0 mmol).

Workup

  1. temperaturethe reaction was heated
  2. temperatureto reflux for 3 hours
  3. customthe organics were removed in vacuo
  4. customthe resulting residue was purified by silica gel chromatography
  5. washeluting with heptane to 10% methanol in dichloromethane
  6. customto obtain

Sources & evidence

ORD record
ord-5f60039cd4224f06ac7d8fa176601e6f
Source dataset
uspto-grants-2012_07
Patent number
US08211927B2

Reaction notes

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