Water → Ethyl 3-(benzothiophen-2-yl)-5-ethyl-4,5-dihydro-5-isoxazolecarboxylate

HRID 225951Notes

Reaction equation

HRID 225951 reaction equation
[S:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[C:2]1[CH:10]=[N:11][OH:12].[CH2:13]([C:15](=[CH2:21])[C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH3:14].Cl[O-].[Na+].O>C1COCC1.C(N(CC)CC)C>[S:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[C:2]1[C:10]1[CH2:21][C:15]([CH2:13][CH3:14])([C:16]([O:18][CH2:19][CH3:20])=[O:17])[O:12][N:11]=1

Participants

7

Reactant 4

HCID 962WaterHCID 291416Ethyl 2-methylidenebutanoateHCID 23665760Sodium HypochloriteHCID 85255485Benzothiophen-2-aldehyde oxime

Product 1

HCID 68829660Ethyl 3-(benzothiophen-2-yl)-5-ethyl-4,5-dihydro-5-isoxazolecarboxylateYield 18%

Reagents, catalysts & solvents 2

HCID 8471TriethylamineCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

Benzothiophen-2-aldehyde oxime derivative (400 mg, 2.26 mmol) prepared according to the same procedure as Preparation 1 was dissolved in THF (25 ml), and the mixture was kept at 0□. Ethyl 2-ethylacrylate (434 mg, 1.5 Eq) and triethylamine (7 drops) were dissolved in THF (5 ml), thus obtained solution was slowly added to the above, and sodium hypochlorite solution (6.0 ml) was further added. The reaction solution was warmed to room temperature and stirred for 4 hours. Water (20 ml) was added, and the mixture was extracted with ethyl acetate (40 ml×2), washed with aqueous sodium chloride solution (20 ml), dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (20% ethyl acetate-hexane) to give the title compound (121 mg, Yield 18%).

Workup

  1. customaccording to the same procedure as Preparation 1
  2. additionwas further added
  3. extractionthe mixture was extracted with ethyl acetate (40 ml×2)
  4. washwashed with aqueous sodium chloride solution (20 ml)
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customThe residue was purified by column chromatography (20% ethyl acetate-hexane)

Sources & evidence

ORD record
ord-e2fa1e311a79428eb715b292d4618aea
Source dataset
uspto-grants-2009_07
Patent number
US07557133B2

Reaction notes

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