Water → HCID 58537227, Verbindung

Reaktionsgleichung

[C:1]1([C:7]2[C:11]([C:12]([O:14][CH3:15])=[O:13])=[C:10]([C:16]([O:18]C)=[O:17])[O:9][N:8]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.O.[Li+].[OH-]>CO>[CH3:15][O:14][C:12]([C:11]1[C:7]([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)=[N:8][O:9][C:10]=1[C:16]([OH:18])=[O:17])=[O:13]

Komponenten

Versuchsvorschrift

To a solution of dimethyl 3-phenylisoxazole-4,5-dicarboxylate (770 mg, 2.95 mmol) in MeOH (15 mL)/water (5.00 mL) at rt was added LiOH, hydrate (124 mg, 2.95 mmol) and the reaction mixture was allowed to stir at rt for 1 hr. The MeOH was removed in vacuo and the remaining aqueous solution was diluted with water (5 mL). The pH was adjusted to <1 with 1N HCl and the mixture was extracted with EtOAc (40 mL). The organic layer was washed with brine (25 mL), dried (MgSO4) and concentrated to afford 4-(methoxycarbonyl)-3-phenylisoxazole-5-carboxylic acid (709 mg, 2.87 mmol, 97% yield) as a colorless oil. HPLC retention time=1.99 minutes (YMC Combi 4.6×50 mm S-5 ODS column) eluting with 10-90% aqueous methanol+0.2% phosphoric acid over a 4 minute gradient. MS: (M+H)=248.13. 1H NMR (400 MHz, chloroform-d) δ ppm 3.89 (s, 3H) 7.51 (m, 5H).