PHTHALAZINONE DERIVATIVES

Phthalazinone derivatives The invention relates to compounds of formula I (I) wherein A1 and A2 are hydrogen; unsubstituted or substituted lower alkyl, lower alkenyl or lower alkynyl; heterocyclyl-lower alkyl; acyl; lower alkylsulfonyl; or arylsulfonyl; or together are unsubstituted or substituted lower alkylene; Ar1 and Ar2 are aryl, heteroaryl or unsubstituted or substituted cycloalkyl; X is oxygen or sulfur; and Q is a divalent radical of the formula , which is bonded by its Y-carrying carbon atom to the Q-binding carbon atom and by its RB-carrying nitrogen atom to the RA-carrying nitrogen atom in formula I, wherein Y is oxygen or sulfur, and RA and RB are hydrogen, unsubstituted or substituted lower alkyl or acyl; or Q is a divalent radical of the formula , which is bonded by its carbon atom to the Q-binding carbon atom and by its nitrogen atom to the RA-carrying nitrogen atom in formula I, RA having the meanings given with the exception of acyl; salts thereof and tautomers thereof. They inhibit protein kinases, such as tyrosine protein kinases.