Patent ID: 6723849
Filing Date: 2004-04-20
Classification: C07D

Abstract:
A process for synthesizing camptothecin derivatives having the formula: whereA is â€”(CH2)nâ€” where n is 1 to 6; and R1, R2, and R3 are individually lower alkyl or aryl, the process comprising the steps of: a) providing a quantity of substantially pure camptothecin, and dissolving in a strong acid; b) adding a strong oxidizing agent to the camptothecin and strong acid solution to form a reaction mixture, then adding the reaction mixture to a vessel containing: i) an aldehyde having the formula R1R2R3Siâ€”(CH2)nCHO in sufficient quantities to react with the reaction mixture; ii) a nonpolar, aprotic solvent; and iii) an iron salt; c) agitating the vessel for a predetermined time to produce the formula I compound.