(EN) Patent 514523 Described is the compound of formula I wherein: R1 is hydrogen, -NO2, -CN, -halogen, -OR5, -R6OR7, -COOR7, -CONR8R9, -NR10R11, -NHCOR12, -NHSO2R13, or straight-chained lower alkyl which optionally is substituted by hydroxy and/or halogen; R2 and R4 are each independently hydrogen, -halogen, -NO2, -CF3, or straight chained lower alkyl; R3 is hydrogen, -cycloalkyl, -aryl, -heterocycle, -heteroaryl, -COOR7-CN, -alkenyl,-CONR8R9, -alkynyl, or lower alkyl which optionally is substituted by hydroxy, -OR9, F, and/or aryl; R5 is lower alkyl which optionally is substituted by halogen; R6 is lower alkyl; R7 is hydrogen or lower alkyl; R8 and R9 are each independently hydrogen or lower alkyl which itself optionally are substituted by hydroxy and/or -NH2; alternatively, R8 and R9 may form a 5-or 6-membered heterocycle which optionally is substituted by hydroxy, -NH2, and/or lower alkyl; R10, R11 and R12 are each independently hydrogen or lower alkyl; R13 is lower alkyl which optionally is substituted by halogen and/or -NR14R15; and R14 and R15 are each independently hydrogen or lower alkyl which optionally are substituted halogen, or alternatively,-NR14R15 is a heterocycle; and the pharmaceutically acceptable salts of compounds of formula I. Also described are the compounds of 3 and 5 wherein R1 to R4 are as defined above. The compounds may used as the active ingredient of pharmaceutical compositions for the treatment of breast, colon, lung and prostate tumors.