| abstract |
The present invention provides a compound of formula (I): <CHEM> wherein R<1> is hydrogen, C1-4 alkyl, acetyl or formyl; R<2> and R<3> are the same or different and are hydrogen or C1-4 alkyl; R<4> is NR<1><1>R<1><2>; R<1><1>, R<1><2>, R<5> and R<6> are the same or different and are hydrogen, C1-4 alkyl or C1-12 acyl; R<7>, R<8>, R<9> and R<1><0> are the same or different and are hydrogen, halo, C1-4 haloalkyl, C1-4 alkyl and C1-4 alkoxy; and n is 2, 3, 4 or 5; m is o or an integer from 1 to 6; or a salt thereof, methods for the preparation of the compounds of the formula (I), intermediates in their preparations, pharmaceutical formulations containing them, and their use in the treatment of tumours. |