Highly lipophilic camptothecin derivatives for the treatment of cancer

摘要

ompounds having formula (I), wherein R1 is acyl of formula -C(O)R2 wherein R2 is C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl or aryl; or R1 is C2-8 alkenyl or C2-8 alkynyl, each of which is optionally substituted by one or more halogen atoms, hydroxy groups, C1-6 alkyl or C1-6 alkoxy groups; or R1 is halo; oxo, in which case the 1,2- and 6,7-ring double bonds are replaced by a single 2,6-ring double bond; or -S-R3, wherein R3 is C1-6 alkyl, aryl or halo- or C1-6 alkyl-substituted aryl; or R1 is -S(O)-C1-6 alkyl; -OSO2CF3; or -SiR8R9R10, -R5-SiR8R9R10 or -S-R5-SiR8R9R10 wherein R5 is C1-6 alkylene, C2-6 alkenylene or C2-6 alkynylene and each of R8, R9 and R10 is individually hydrogen or C1-6 alkyl; and R11 is hydrogen, hydroxy or a hydroxy-protecting group which protects the hydroxy group against triflylation; in the form of the free bases or pharmaceutically acceptable acid addition salts thereof are highly lipophilic, lactone stable, do not require metabolic activation, and are anti-neoplastic compounds