The invention relates to compounds of the formulae (I) and (II) in which R1, R2, R3, R4, R5, R8, X and m are each as defined in the claims, and/or the physiologically acceptable salts, tautomers and stereoisomers thereof, including the mixtures thereof in all ratios. The compounds of the formula (I) can be used for inhibition of serine/threonine protein kinases and for sensitization of cancer cells to anticancer drugs and/or ionizing radiation. The invention also provides for the use of the compounds of the formula (I) in the prophylaxis, treatment or monitoring the course of cancer, tumors, metastases or angiogenetic disorders, in combination with radiotherapy and/or an anticancer drug. The invention further relates to a process for preparing the compounds of the formula (I) by reacting compounds of the formula (II) and optionally converting a base or acid of the compounds of the formula (I) to one of the salts thereof.
