The present invention encompasses compounds of general formula (I) wherein the groups R2 to R4 and X are defined 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.本発明は、過剰又は異常な細胞増殖を特徴とする疾患の治療に適した下記一般式(I)(式中、基R2~R4及びXは、請求項1の定義どおりである)の化合物、この種の化合物を含む医薬製剤及びそれらの薬物としての使用を包含する。【選択図】なし