A compound of formula (I) ** Formula ** in which -presents NR5, and Y represents CHRY in which RY represents hydrogen, or (C1-3) alkyl； and -and R3b together with the carbon atom to which they are attached to form a carbonyl group, or -of R2a, R2b, R3a and R3b independently represent hydrogen, or (C1-3) alkyl； and the rest of R2a, R2b, R3a and R3b represent hydrogen； or - represents CHRX in which RX represents hydrogen, or (C1-3) alkyl, and Y represents NR5； and -and R2b together with the carbon atom to which they are attached to form a carbonyl group, or -of R2a, R2b, R3a and R3b independently represent hydrogen, or (C1-3) alkyl； and the rest of R2a, R2b, R3a and R3b represent hydrogen； or -present NR5 and Y represents a direct link； R2a and R2b both represent hydrogen； and R3a and R3b both represent hydrogen； or -presents NR5, Y represents -C (O) -； and R2a, R2b R3a and R3b all represent hydrogen； or -presents -C (O) -, Y represents NR5； and R2a, R2b R3a and R3b all represent hydrogen； R5 represents -yl (C1-6)； -lo (C1-4) mono-substituted with (C1-3) alkoxy, cyano, vinyl； ethynyl, or (C1-3) alkoxycarbonyl； -R10 in which R10 represents (C1-5) alkyl； (C1-5) alkoxy； phenyl； phenyl-oxy； phenyl (C1-3) alkyl -； phenyl (C1-3) alkyl-oxy-； C3-6 cycloalkyl (C1-3) alkyl； alkenoxy (C3-4)； (C3-4) alkyloxy； fluoroalkyl (C1-3)； fluoroalkoxy (C1-3)； (C1-3) alkoxy (C2-3) alkoxy； (C1-3) alkoxy-(C1-3) alkyl； C3-6 cycloalkyl optionally containing an oxygen atom in the ring, wherein said cycloalkyl is optionally mono- or di-substituted in which the substituents independently are fluorine or fluoroalkyl (C1)； 5-membered unsubstituted heteroaryl； or -25 NR10aR10b in which R10a and R10b independently represent hydrogen, (C1-4) alkyl or cycloalkyl (C3-6), or R10a and R10b together with the nitrogen to which they are attached to form a saturated ring of 5 to 7 members ； --R11 in which R11 represents (C1-5) alkyl or phenyl； -alkyl (C2-4)； -C3-6alkyl optionally containing an oxygen atom in t
