Hydroxyamine hydrochloride → Ethyl 5-cyclopropylisoxazole-4-carboxylate

HRID 2107634Notes

Reaction equation

HRID 2107634 reaction equation
Cl.[NH2:2]O.[CH:4]1([C:7](=[O:18])[C:8](=[CH:14]OCC)[C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:6][CH2:5]1>CCO>[CH:4]1([C:7]2[O:18][N:2]=[CH:14][C:8]=2[C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH2:6][CH2:5]1

Participants

4

Reactant 2

HCID 443297Hydroxyamine hydrochlorideHCID 57004106Ethyl beta-cyclopropyl-alpha-ethoxymethylene-beta-ketopropionate

Product 1

HCID 14819891Ethyl 5-cyclopropylisoxazole-4-carboxylateYield 57.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of hydroxylamine hydrochloride (105.0 g, 1.51 mole), ethyl β-cyclopropyl-α-ethoxymethylene-β-ketopropionate (320.0 g, 1.51 mole) [prepared in Step A] and 1200 ml of EtOH was heated at reflux for 2 h. The solvent was removed in vacuo and the residue was partitioned between water and ether. The organic phase was separated, washed again with water, dried and evaporated to leave a dark, greasy solid. Trituration of the crude product under Skellysolve B gave 158 g of the title compound.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 2 h
  3. customThe solvent was removed in vacuo
  4. customthe residue was partitioned between water and ether
  5. customThe organic phase was separated
  6. washwashed again with water
  7. customdried
  8. customevaporated
  9. customto leave a dark, greasy solid

Sources & evidence

ORD record
ord-b12de4bad36549e7b0205b25272885df
Source dataset
uspto-grants-1990_06
Patent number
US04935434

Reaction notes

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