7H-pyrido (3,4-d) pyrimidin-8-ones, their preparation and use as inhibitors of protein kinases.

A compound according to formula I ** (See formula) ** wherein R1 is halogen, alkyl, alkoxy, halogenated alkyl or halogenated alkoxy; R2 is hydrogen, halogen, alkyl, alkoxy, halogenated alkyl or halogenated alkoxy; R3 is alkyl optionally substituted one or more times with cyano, -OR, -NRR ', -C (O) NRR', -NR-C (O) -alkyl, -S (O) 2NRR ', - NR-S (O) 2-alkyl, heteroaryl, hetero- cyclyl, unsubstituted phenyl or phenyl substituted one or more times by halogen, alkyl, alkoxy or cyano; R4 is a) alkyl, optionally substituted once or several times with -OR or -NRR '; b) phenyl, optionally substituted one or more times with alkyl, alkoxy, heterocyclyl, -C (O) NRR ', -NR-C (O) -alkyl, -S (O) -alkyl, -S (O) 2NR alkyl or -NR-S (O) 2-alkyl, wherein all alkyl and alkoxy groups are optionally substituted one or several times with -OR or -NRR '; or c) heterocyclyl; R and R 'are hydrogen or alkyl; wherein the term "alkyl", as used herein, means a saturated hydrocarbon straight or branched chain having 1 to 4 carbon atoms; the term "halogenated alkyl" as used herein means an alkyl group as defined above which is substituted one or more times by halogen; the term "alkoxy", as used herein means an alkyl-O wherein alkyl is defined as above; the term "halogenated alkoxy" as used herein, means an alkoxy group as defined above which is substituted one or more times by halogen; the term "heteroaryl" means an aromatic mono- or bicyclic ring of 5 to 10, preferably 5 to 6 atoms, which contains up to 3 heteroatoms independently selected from N, O or S, the remaining being carbon ring atoms. These heteroaryl groups can be optionally substituted one to three times by alkyl; the term "heterocyclyl" means a monocyclic saturated hydrocarbon ring of 5 to 6 atoms, which contains up to 3 heteroatoms selected independently from N, O or S, the remaining being carbon ring atoms. This saturated heterocyclic group may be optionally substituted one to three times by alkyl; and all pharmaceutically acceptable salts thereof.