[Br:1][C:2]1[CH:3]=[CH:4][C:5]([O:13]C(=O)C)=[C:6]2[C:11]=1[NH:10][C:9](=[O:12])[CH2:8][CH2:7]2.Cl>>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([OH:13])=[C:6]2[C:11]=1[NH:10][C:9](=[O:12])[CH2:8][CH2:7]2The thus-obtained 21 g of 8-bromo-5-acetyloxy-3,4-dihydrocarbostyril are dispersed in 150 ml of 8N-hydrochloric acid. The dispersion is heated under reflux conditions for 3 hours and then cooled. Insoluble matter thus formed is separated by filtration, washed with water and dried, and recrystallized from methanol-water to obtain 14 g of 8-bromo-5-hydroxy-3,4-dihydrocarbostyril in the form of colorless needle-like crystals with a melting point of 212°-213° C.
Wird geladen…