Hydroxyamine hydrochloride → Ethyl 5-cyclopropylisoxazole-4-carboxylate
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>C(O)C>[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]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
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 ethanol was refluxed 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.