| abstract |
Compounds of the formula (I) or salts thereof, wherein the dotted line represents a single or double bond, R1 is alkyl or amino optionally substituted by alkyl, alkanoyl or benzyl group: R2, R3, R4 and R5 are the same or different and each is selected from hydrogen, phenyl, halo, nitro, a group S(O)nR8 wherein n is the integer 0, 1 or 2 and R8 is halo or alkyl or a group NR9R10 are both hydrogen, a group NR11R12 wherein R11 and R12 are the same or different and each is hydrogen or alkyl, a group OR13 wherein R13 is hydrogen or C1-4 alkyl substituted by halo; a C1-4 aliphatic group optionally substituted by a group OR14 or NR14R15 wherein R14 and R15 are the same or different and each is hydrogen or alkyl; ot two of R2 to R5 are linked together to form a benzp group, one of R2 to R3 is a group X-Y-R16 wherein X is CH2, NR17, CO, or S(O)m and Y is CH2, NR17, O or S(O)m, or X-Y is CH2,NR17, -CH=CH- or -N=N-, are disclosed as pharmacological agents useful in the treatment of tumors. Pharmaceutical compositions and methods for the preparation of compounds of formula (I) are also disclosed. |