C([O:3][C:4](=[O:12])[C:5]1[CH:10]=[CH:9][CH:8]=[N:7][C:6]=1Cl)C.[O:13]1[C:17]2[CH:18]=[CH:19][C:20]([OH:22])=[CH:21][C:16]=2[O:15][CH2:14]1.C(=O)([O-])[O-].[Cs+].[Cs+]>O1CCOCC1.[OH-].[Li+].O>[O:13]1[C:17]2[CH:18]=[CH:19][C:20]([O:22][C:6]3[N:7]=[CH:8][CH:9]=[CH:10][C:5]=3[C:4]([OH:3])=[O:12])=[CH:21][C:16]=2[O:15][CH2:14]12-Chloro-nicotinic acid ethyl ester (10 g), benzo[1,3]dioxol-5-ol (sesamol, 8.2 g), and cesium carbonate (21 g) were mixed in anhydrous dioxane (40 mL) and the resulting slurry heated to reflux for 16 h. In a separate flask, lithium hydroxide (12.9 g) was dissolved in water (80 mL) with warming and then added to the refluxing mixture, which was heated for an additional 4 h. The mixture was cooled to ambient temperature and concentrated in vacuo to remove the dioxane. Concentrated hydrochloric acid was added dropwise until the pH=3. The acidified solution was then extracted with ethyl acetate (7×100 mL) to yield crude product, which was recrystallized from ethyl acetate to yield the purified title compound (10.8 g).
読み込み中…
