The invention relates to the bicyclic heterocycles of the general formula (I), wherein Ra, Rb, Rc, Rd and X are defined as in claim 1, the tautomers, stereoisomers, mixtures and salts thereof, especially the physiologically acceptable salts thereof with inorganic or organic acids, which have valuable pharmacological properties, especially an inhibitory effect on tyrosine kinase-mediated signal transduction. The invention also relates to the use of the bicyclic heterocycles in the treatment of diseases, especially cancer diseases and of benign prostate hyperplasia (BPH), of diseases of the lung and the respiratory system, and further to the production of the bicyclic heterocycles.