[O:1]=[C:2]1[NH:6][C:5]2[CH:7]=[CH:8][C:9]([C:11]([O:13]CC)=[O:12])=[CH:10][C:4]=2[O:3]1.[Li+].[OH-]>C1COCC1>[O:1]=[C:2]1[NH:6][C:5]2[CH:7]=[CH:8][C:9]([C:11]([OH:13])=[O:12])=[CH:10][C:4]=2[O:3]1To ethyl 2-oxo-2,3-dihydrobenzo[d]oxazole-6-carboxylate in THF (20 mL) was added LiOH (2 g in 10 mL water). The mixture was stirred at room temperature for 20 hours. The solvent was evaporated. The residue was taken up in water and acidified with 5 N HCl to pH=5. The solid was recovered by filtration, washing with water, to provide the pure product as a tan solid (1.44 g, 80%). LCMS (API-ES) m/z: 180 (M+H+).
読み込み中…