SUBSTITUTED CAMPTOTHECIN DERIVATIVES AND PROCESS FOR THEIR PREPARATION

摘要

The present invention relates to substituted camptothecin derivatives of formula (I) wherein the symbol ---- represents a single or double bond; R1, R2 and R3 are as defined under (a) or (b) below: (a) R1 and R2 are, each independently, hydrogen; C1-C4 alkyl; C3-C7 cycloalkyl; phenyl C1-C6 alkyl; an optionally substituted phenyl ring; -NR5R6 wherein one of R5 and R6 is hydrogen, C1-C6 alkyl or benzyl and the other is hydrogen, C1-C6 alkanoyl, an optionally substituted C1-C6 alkoxycarbonyl, an optionally substituted benzoyl, phenyl C1-C6 alkanoyl, an optionally substituted C1-C6 alkoxycarbonyl, an optionally substituted phenoxycarbonyl or phenyl C1-C6 alkoxycarbonyl, or R5 and R6, combined together with the nitrogen atom to which they are linked, form a 4-7 membered saturated, optionally substituted, heteromonocyclic ring residue; COOR8 wherein R8 is hydrogen, C1-C6 alkyl, C3-C7 cycloalkyl or phenyl C1-C6 alkyl; or COR9 wherein Rg is C1-C6 alkyl, C3-C7 cycloalkyl, phenyl C1-C6 alkyl, an optionally substituted phenyl ring or NR10R11 wherein R10 and R11 are, each independently, hydrogen or C1-C6 alkyl; and R3 is hydrogen, C1-C6 alkyl or an optionally substituted phenyl ring; or (b) R1 and R3, combined together, form a 5-8 membered, optionally substituted, carbomonocyclic ring; and R2 is hydrogen, C1-C4 alkyl or C3-C7 cycloalkyl; R4 is hydrogen, C1-C6 alkyl, C3-C7 cycloalkyl or phenyl C1-C6 alkyl; X is hydrogen, C1-C6 alkyl, C3-C7 cycloalkyl, C1-C6 alkoxy, C3-C7 cycloalkoxy, C1-C6 alkanoyloxy, benzoyloxy, amino, hydroxy, nitro, halogen or it is a methylenedioxy group linked to the positions 10 and 11 of the molecule, and the pharmaceutically acceptable salts thereof. The compounds according to the invention are useful in therapy as antitumor agents.