The present invention relates to compounds of general formula (I), wherein R1, R2, R3, R4, l, X and Z are as defined in the present application, and their pharmaceutically acceptable salts, with respect to pharmaceutical compositions containing the compounds and salts, and to methods of using the compounds, salts and compositions to treat abnormal cell growth, including cancer.本發明涉及通式(I)的化合物其中R1、R2、R3、R4、L、X與Z如本申請中所定義,及其藥學上可接受的鹽,關於包含該化合物與鹽的藥物組合物,及關於將所述化合物、鹽與組合物用於治療異常細胞生長(包括癌)的方法。