The invention concerns compounds of Formula (I) or pharmaceutically-acceptable salts thereof, wherein R1and R2 have any of the meanings defined hereinbefore in the description; processes for their preparation, pharmaceutical compositions containing them and their use in the treatment of cell proliferative disorders.本發明係關於式(I)化合物或其醫藥學上可接受之鹽,其中R1及R2具有在以下說明書中所定義之任一含義;其製備方法;含有其之醫藥組合物及其在治療細胞增殖性病症中之用途。