Sulfuric Acid → Ethyl 4-methyl-3-(thiophen-2-yl)isoxazole-5-carboxylate

HRID 2388188Notes

Reaction equation

HRID 2388188 reaction equation
O[N:2]=[C:3]([C:13]1[S:14][CH:15]=[CH:16][CH:17]=1)[CH:4]([CH3:12])[C:5](=[O:11])[C:6]([O:8][CH2:9][CH3:10])=[O:7].S(=O)(=O)(O)O.C(=O)(O)[O-].[Na+]>C(O)C>[CH3:12][C:4]1[C:3]([C:13]2[S:14][CH:15]=[CH:16][CH:17]=2)=[N:2][O:11][C:5]=1[C:6]([O:8][CH2:9][CH3:10])=[O:7]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 516892Sodium BicarbonateHCID 86648118Ethyl 4-(hydroxyimino)-3-methyl-2-oxo-4-(thiophen-2-yl)butanoate

Product 1

HCID 67530636Ethyl 4-methyl-3-(thiophen-2-yl)isoxazole-5-carboxylateYield 54.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Ethyl 4-(hydroxyimino)-3-methyl-2-oxo-4-(thiophen-2-yl)butanoate (7.7 g, 30.2 mmol) and concentrated sulfuric acid (8 mL) were added to 120 mL of absolute ethanol and the mixture was refluxed for 20 hours. After the mixture cooled to room temperature, saturated sodium bicarbonate solution was added to neutralize the mixture. The product was extracted with EtOAc and the combined organic layer was dried over MgSO4 and concentrated to give 3.9 g of the title compound. MS: (+) m/z 238.38 (M+1).

Workup

  1. temperaturethe mixture was refluxed for 20 hours
  2. extractionThe product was extracted with EtOAc
  3. dry with materialthe combined organic layer was dried over MgSO4
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-7ceb9cda32c54a849d60343ae2970238
Source dataset
uspto-grants-2012_09
Patent number
US08269008B2

Reaction notes

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