| abstract |
The present invention provides compounds represented by formula (1): wherein, R, R, R and R are as defined in the specification, in all their stereoisomeric and tautomeric forms and mixtures thereof in all ratios, and their pharmaceutically acceptable salts, pharmaceutically acceptable solvates, pharmaceutically acceptable polymorphs and prodrugs. The invention also relates to processes for the manufacture of compounds of formula (1) and pharmaceutical compositions containing them. The compounds and the pharmaceutical compositions of the present invention are useful for the treatment of cancer. The present invention further provides a method of treatment of cancer by administering a therapeutically effective amount of the said compound of formula (1) or its pharmaceutical composition, to a mammal in need thereof. |