| abstract |
The present invention relates to pyrimido[5,4-d]pyrimidines of general formula (I) in which A2, A4, A6 and A8 are as defined in claim 1, their tautomers, stereoisomers and salts, especially their physiologically acceptable salts with inorganic or organic acids or bases exhibiting valuable pharmacological properties, especially an inhibitory effect on signal transduction produced by tyrosinkinases, their use in treating disorders, especially tumours, and their production. |