10-Aminocamptothecin → Hydroxycamptothecin
反応式
[CH3:1][CH2:2][C@@:3]1([OH:27])[C:8](=[O:9])[O:7][CH2:6][C:5]2[C:10]([N:12]3[C:16](=[CH:17][C:4]1=2)[C:15]1[N:18]=[C:19]2[C:24](=[CH:25][C:14]=1[CH2:13]3)[CH:23]=[C:22](N)[CH:21]=[CH:20]2)=[O:11].N([O-])=[O:29].[Na+]>S(=O)(=O)(O)O.C(Cl)(Cl)Cl>[CH3:1][CH2:2][C@@:3]1([OH:27])[C:8](=[O:9])[O:7][CH2:6][C:5]2[C:10]([N:12]3[C:16](=[CH:17][C:4]1=2)[C:15]1[N:18]=[C:19]2[C:24]([CH:23]=[C:22]([OH:29])[CH:21]=[CH:20]2)=[CH:25][C:14]=1[CH2:13]3)=[O:11]参加物
5
実験手順
10-Aminocamptothecin (50 mg, 0.138 m-mol) is dissolved in a 10% aqueous solution of sulfuric acid (5 ml). To this solution in a salted ice bath is added dropwise slowly an aqueous solution of sodium nitrite (9.5 mg, 0.138 m-mol) with stirring. After the addition of sodium nitrite, the mixture is further stirred for 10 minutes in a salted ice bath. To the reaction mixture is added conc. sulfuric acid (1 ml), and the whole is boiled under reflux for 2 hours. The reaction mixture is diluted with ice water (200 ml) and chloroform (200 ml) is added. The mixture is shaken in a separating funnel and the resultant emulsion is filtered through celite. The chloroform phase containing camptothecin formed as by-product by side reactions is dried over magnesium sulfate, filtered and evaporated until dryness under reduced pressure whereby camptothecin (8 mg) is recovered. On the other hand, a solid on the celite, which is insoluble in chloroform-water, is taken up in 20% MeOH-CHCl3 (200 ml) and the solution is evaporated until dryness under reduced pressure whereby 28 mg (yield: 66.5% ) of the title compound is obtained as light yellow crystals. M.P. (with decomp.) 270°-272° C. (from pyridine-methanol)