| abstract |
New camptothecin derivatives and a process for preparing same are disclosed, which are represented by the general formula:n wherein R¹ represents a lower alkyl group, R² represents a hydrogen atom or an amino, hydroxyl, lower acylamino or lower alkoxy group, R³ represents a hydrogen or halogen atom or a lower alkyl, hydroxyl, lower alkoxy, nitro, amino, cyano or di(lower alkyl)amino group, R⁴ represents a hydrogen or halogen atom or a lower alkyl, hydroxyl, lower alkoxy, lower alkylthio, amino, cyano or di(lower alkyl)amino group, and R⁵ represents a hydrogen or halogen atom or a hydroxyl or lower alkoxy group, with the proviso that all of the R², R³, R⁴ and R⁵ substituents should not be a hydrogen atom and also that if any one of the R², R³, R⁴ and R⁵ is a hydroxyl or lower alkoxy group, all of the other three substituents should not be a hydrogen atom. The new camptothecin derivatives are useful as anti-tumor drugs or intermediates therefor. |