The present invention encompasses compounds of general formula (1)wherein A, B, X, R1to R3are defined as in claim 1, which are suitable for the treatment of diseases characterised by excessive or abnormal cell proliferation, and their use for preparing a medicament having the above-mentioned properties.本發明涵蓋通式(1)化合物其中A、B、X、R1至R3如請求項1中所定義,該等化合物適合治療特徵為過度或異常細胞增殖之疾病,且涵蓋其用於製備具有上述特性之藥劑之用途。