Ethanol → Ethyl 5-ethoxy-4,5-dihydro-1,2-oxazole-3-carboxylate
Reaktionsgleichung
[CH2:1]([O:3][CH:4]=[CH:5][C:6](=O)[C:7]([OH:9])=[O:8])[CH3:2].Cl.[NH2:12][OH:13].O.[CH2:15](O)[CH3:16]>>[CH2:1]([O:3][CH:4]1[O:13][N:12]=[C:6]([C:7]([O:9][CH2:15][CH3:16])=[O:8])[CH2:5]1)[CH3:2]Komponenten
5
Versuchsvorschrift
17.22 g of 4-ethoxy-2-oxo-3-butenoic acid prepared according to the method of L. Tietze et al. (Lutz-F. Tietze, Heinrich Meier and Edgar Voss, Synthesis 1988, 274) are dissolved in 50 ml of anhydrous ethanol, and 7.34 g of hydroxylamine hydrochloride is added thereto, and the mixture is stirred at room temperature for 4 hours. The reaction mixture is added with water and extracted with methylene chloride. The organic layer is washed with water, dried, and evaporated. The resulting residue is distilled under reduced pressure to yield 14.3 g of ethyl 5-ethoxyisoxazoline-3carboxylate. (yield 76%)