Ethyl 2,4-dioxovalerate → Ethyl 5-methylisoxazole-3-carboxylate

HRID 2248971Notes

Reaction equation

HRID 2248971 reaction equation
O=[C:2]([CH2:8][C:9](=[O:11])[CH3:10])[C:3]([O:5][CH2:6][CH3:7])=[O:4].Cl.[NH2:13]O.C(=O)(O)[O-].[Na+]>C(O)C>[CH3:10][C:9]1[O:11][N:13]=[C:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])[CH:8]=1

Participants

5

Reactant 3

HCID 69208Ethyl 2,4-dioxovalerateHCID 443297Hydroxyamine hydrochlorideHCID 516892Sodium Bicarbonate

Product 1

HCID 76677Ethyl 5-methylisoxazole-3-carboxylateYield 56.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of ethyl 2,4-dioxovalerate (25 ml, 178 mmol), hydroxylamine hydrochloride (13.7 g, 197 mmol) and sodium bicarbonate (15.4 g, 183 mmol) in ethanol (125 ml) were heated at reflux for 2.5 h, cooled and the solvent removed under reduced pressure. The residue was taken up in chloroform and washed with water, the organic layer separated and dried (MgSO4). Solvent removal and distillation under reduced pressure gave the desired product (15.44 g, 100 mmol, 56%); b.p. 82°-86° C. at 0.5 mm Hg; νmax (film) 3120, 2980, 2930, 1730, 1600, 1450, 1270, 1200, 1100, 1020, 915, 830, 780 cm-1 ; δH (CDCl3) 1.40(3H,t,J 7 Hz, OCH2CH3), 2.50(3H,s,CH3 -5), 4.40(2H,q,J 7 Hz, OCH2CH3), 6.40(1H,s,CH-4).

Workup

  1. temperaturewere heated
  2. temperatureat reflux for 2.5 h
  3. temperaturecooled
  4. customthe solvent removed under reduced pressure
  5. washwashed with water
  6. customthe organic layer separated
  7. dry with materialdried (MgSO4)
  8. customSolvent removal and distillation under reduced pressure

Sources & evidence

ORD record
ord-47b53c88abee49409e53febedeae1a9f
Source dataset
uspto-grants-1991_08
Patent number
US05041567

Reaction notes

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