Lithium Hydroxide → 5-(1,1-Dimethylethyl) 6,7-dihydroisoxazolo[4,5-c]pyridine-3,5(4H)-dicarboxylate
Reaktionsgleichung
[OH-].[Li+].[O:3]1[C:11]2[CH2:10][CH2:9][N:8]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:7][C:6]=2[C:5]([C:19]([O:21]CC)=[O:20])=[N:4]1>C(O)C>[C:15]([O:14][C:12]([N:8]1[CH2:9][CH2:10][C:11]2[O:3][N:4]=[C:5]([C:19]([OH:21])=[O:20])[C:6]=2[CH2:7]1)=[O:13])([CH3:18])([CH3:16])[CH3:17]Komponenten
4
Versuchsvorschrift
An aqueous lithium hydroxide solution (0.54 g, 12.88 mol in 12.8 ml) was added dropwise to a solution of 5-tert-butyl 3-ethyl 6,7-dihydroisoxazolo[4,5-c]pyridine-3,5(4H)-dicarboxylate (3.2 g, 10.73 mmol) in ethanol (48 ml) at 0° C. and the mixture was stirred at room temperature for 3 hours. The mixture was then concentrated in vacuo, the residue was acidified with 10% strength citric acid and the mixture was extracted three times with ethyl acetate. The combined organic phases were dried with Na2SO4, filtered and concentrated in vacuo. The crude product was employed directly in the next stage without further purification.