The present invention concerns the compounds of formula wherein a1-a2=a3-a4 represents a divalent radical selected from N—CH═CH—CH, N—CH═N—CH or CH—CH═N—CH; Z represents NH; Y represents —C3-9alkyl-, —C1-5alkyl-NR13—C1-5alkyl-, —C1-6 alkyl-NH—CO— or —CO—NH—C1-6alkyl-; X1 represents —O— or —NR11—; X2 represents —C1-2alkyl-, —O—C1-2alkyl, —O— or —O—CH2—; R1 represents hydrogen or halo; R2 represents hydrogen, cyano, halo, hydroxycarbonyl-, C1-4alkyloxycarbonyl-, Het16-carbonyl- or Ar5; R3 represents hydrogen; R4 represents hydroxy, C1-4alkyloxy-, Ar4—C1-4alkyloxy or substituted C1-4alkyloxy; R11 represents hydrogen; R12 represents hydrogen, C1-4alkyl- or C1-4alkyl-oxy-carbonyl-; R13 represents morpholinyl-C1-4alkyl; Het2 represents morpholinyl or piperidinyl optionally substituted with C1-4alkyl-, preferably methyl; Het14 represents morpholinyl; Het16 represents morpholinyl or pyrrolidinyl; Ar4 represents phenyl; Ar5 represents phenyl optionally substituted with cyano.