[N+:1]([O-:4])(O)=[O:2].[OH:5][C:6]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[O:9][C:8](=[O:16])[CH:7]=1>C(Cl)(Cl)Cl>[OH:5][C:6]1[C:15]2[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=2)[O:9][C:8](=[O:16])[C:7]=1[N+:1]([O-:4])=[O:2]Fuming nitric acid (30 ml) was added to a stirred suspension of 4-hydroxycoumarin (5.0g) in chloroform (500 ml) at room temperature over 2 hours. After a further 2 hours, the solvent was removed in vacuo at room temperature and water (250 ml) added to the residue. Filtration gave the product, m.p. 174°, -5°, (C9H5NO5 required C, 52.18; H, 2.43; N, 6.76. Found: C, 52.00; H, 2.38; N, 6.62).
Wird geladen…