The present invention encompasses compounds of general formula (I)wherein the groups R2 to R4, A, X and m are detined as in claim 1, which are suitable for the treatment of diseases characterised by excessive or abnormal cell proliferation, pharmaceutical preparations which contain compounds of this kind and their use as medicaments.本發明係關於一種通式(I)化合物其中基團R2至R4、A、X及m係如申請專利範圍第1項中所定義,其適用於治療特徵為過量或異常細胞增殖之疾病;含有此類化合物之醫藥製劑及其作為藥劑之用途。