The present invention relates to novel compounds of formula (I)′, pharmaceutically acceptable salts, prodrugs or solvates thereof: wherein R1 is hydrogen or C1-4alkyl; R2 is a group A, K or W wherein A is (II) K is an α or β naphthyl group, optionally substituted by 1 or 2 groups R18, each of them being the same or different; and W is (III) and wherein G is a 5,6-membered monocyclic heteroaryl, or a 8- to 11-membered heteroaryl bicyclic group; such G may be substituted by (R15)p, which can be the same or different; p is an integer from 0 to 5; R3 is selected in the group consisting of: hydrogen, fluorine, and C1-4alkyl; or corresponds to a group X or X1; R4 is selected in the group consisting of: hydrogen, fluorine, and C1-4alkyl; or corresponds to a group X or X1; R5 is hydrogen or C1-4alkyl; R7 is hydrogen or C1-4alkyl; or is a group X, X1, X2 or X3; wherein X is (IV) X1 is (V) X2 is (VI) and X3 is (VII) R6 is hydrogen or C1-4alkyl; or is a group X or X1; R9 is C1-4alkyl; R10 is selected from a group consisting of: hydrogen, halogen, hydroxy, cyano, C1-4alkyl, haloC1-4alkyl, C1-4alkoxy, haloC1-4alkoxy, C1-4alkanoyl and SF5; or corresponds to a group R8; R8 is a 5-6 membered heterocycle group, which may be substituted by one or two substituents selected from a group consisting of: halogen, cyano, C1-4alkyl, haloC1-4alkyl, C1-4alkoxy and C1-4alkanoyl; R11 is selected from a group consisting of: hydrogen, halogen, hydroxy, cyano, C1-4alkyl, haloC1-4alkyl, C1-4aIkoxy, haloC1-4alkoxy, C1-4alkanoyl and SF5; or corresponds to a group R8; R12 is selected from a group consisting of: hydrogen, halogen, hydroxy, cyano, C1-4alkyl, haloC1-4alkyl, C1-4aIkoxy, haloC1-4alkoxy, C1-4alkanoyl and SF5; or corresponds to a group R8; R13 is selected from a group consisting of: hydrogen, halogen, hydroxy, cyano, C1-4alkyl, haloC1-4alkyl, C1-4alkoxy, haloC1-4alkoxy, C1-4alkanoyl and SF5; or corresponds to a group R8; R14 is selected from a group consisting of: hydrogen, halogen, hydroxy, cyano, C1-4alkyl, haloC1-4alkyl, C1-4aIkoxy, haloC1-4alkoxy, C1-4alkanoyl and SF5; or corresponds to a group R8; R15 is selected from a group consisting of: halogen, hydroxy, cyano, C1-4alkyl, haloC1-4alkyl, C1-4alkoxy, haloC1-4alkoxy, C1-4alkanoyl and SF5; or corresponds to a group R8; R16 is hydrogen, C1-4alkyl, C3-6cycloalkyl or C3-6cycloalkylC1-3alkyl; R17 is hydrogen or C1-4alkyl; R18 is selected from a group consisting of: halog