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

HRID 1194061Notes

Reaction equation

HRID 1194061 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 (1 H, 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-d419921caa2a4bb282221d5b7cc6e477
Source dataset
uspto-grants-1989_03
Patent number
US04812470

Reaction notes

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