A compound of formula in which: R 1 represents a halogen atom or a group selected from: C 1 -C 6 -alkyl, C 3 -C 6 -cycloalkyl, C 1 -C 6 -alkoxy, C 3 -C 6 -cycloalkyloxy, C 1 -C 6 -haloalkyl, C 1 -C 6 -haloalkoxy, cyano, (C 1 -C 6 -alkyl)-S-, (C 1 -C 6 -alkyl)-S(=O)-, (C 1 -C 6 -alkyl)-S(=O) 2 -, (C 1 -C 6 -haloalkyl)-S-, (C 1 -C 6 -haloalkyl)-S(=O)-, (C 1 -C 6 -haloalkyl)-S(=O) 2 -, -C(=O)OR 14, -C(=O)N(R 14)R 15 and -N(R 14)R 15; R 2 represents a hydrogen atom; R 3 represents a hydrogen atom; R 4 represents a hydrogen atom or a halogen atom; X represents a nitrogen atom or a group CR 5; R 5 represents a group selected from: -C(=O)OR 14, R 14 OC(=O)-(C 1 -C 6 -alkyl)-, R 14 OC(=O)-(C 2 -C 6 -alkenyl)-, R 14 OC(=O)-(C 1 -C 6 -alkoxy)-, -C(=O)N(R 15)R 16, R 16 (R 15)NC(=O)-(C 1 -C 6 -alkyl)-, R 16 (R 15)NC(=O)-(C 2 -C 6 -alkenyl)- and R 16 (R 15)NC(=O)-(C 1 -C 6 -alkoxy)-; R 6 represents a hydrogen atom or a halogen atom or a group selected from: C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, C 3 -C 6 -cycloalkyl, C 3 -C 6 -cycloalkyloxy, C 1 -C 6 -haloalkyl, C 1 -C 6 -haloalkoxy and cyano; R 7 represents a hydrogen atom; R 8 represents a hydroxymethyl group, and R 9, R 10 and R 11 represent independently of one another a hydrogen atom or a methyl group, and R 12 represents a hydrogen atom; or R 8 represents a methyl group, and R 9, R 10 and R 11 represent independently of one another a hydrogen atom or a methyl group, and R 12 represents a hydroxy group; R 13 represents a hydrogen atom; R 14 represents a hydrogen atom or a group selected from: C 1 -C 6 -alkyl and C 3 -C 6 -cycloalkyl; R 15 and R 16 are independently of each other selected from: hydrogen and C 1 -C 6 -alkyl; or R 15 and R 16 together with the nitrogen atom to which they are attached form a 4- to 6-membered heterocycloalkyl; or a stereoisomer, an N-oxide, a hydrate, a solvate, or a salt thereof, or a mixture of same. R 1 represents a halogen atom or a group selected from: C 1 -C 6 -alkyl, C 3 -C 6 -cycloalkyl, C 1 -C 6 -alkoxy, C 3 -C 6 -cycloalkyloxy, C 1 -C 6 -haloalkyl, C 1 -C 6 -haloalkoxy, cyano, (C 1 -C 6 -alkyl)-S-, (C 1 -C 6 -alkyl)-S(=O)-, (C 1 -C 6 -alkyl)-S(=O) 2 -, (C 1 -C 6 -haloalkyl)-S-, (C 1 -C 6 -haloalkyl)-S(=O)-, (C 1 -C 6 -haloalkyl)-S(=O) 2 -, -C(=O)OR 14, -C(=O)N(R 14)R 15 and -N(R 14)R 15; R 2 represents a hydrogen atom; R 3 represents a hydrogen atom; R 4 represents a hydrogen atom or a halogen atom; X represents a nitrogen atom or a group CR 5; R 5 represents a group selected from: -C(=O)OR 14, R 14 OC(=O)-(C 1 -C 6 -alkyl)-, R 14 OC(=O)-(C 2 -C 6 -alkenyl)-, R 14 OC(=O)-(C 1 -C 6 -alkoxy)-, -C(=O)N(R 15)R 16, R 16 (R 15)NC(=O)-(C 1 -C 6 -alkyl)-, R 16 (R 15)NC(=O)-(C 2 -C 6 -alkenyl)- and R 16 (R 15)NC(=O)-(C 1 -C 6 -alkoxy)-; R 6 represents a hydrogen atom or a halogen atom or a group selected from: C 1 -C 6 -alkyl, C 1 -C 6 -alkoxy, C 3 -C 6 -cycloalkyl, C 3 -C 6 -cycloalkyloxy, C 1 -C 6 -haloalkyl, C 1 -C 6 -haloalkoxy and cyano; R 7 represents a hydrogen atom; R 8 represents a hydroxymethyl group, and R 9, R 10 and R 11 represent independently of one another a hydrogen atom or a methyl group, and R 12 represents a hydrogen atom; or R 8 represents a methyl group, and R 9, R 10 and R 11 represent independently of one another a hydrogen atom or a methyl group, and R 12 represents a hydroxy group; R 13 represents a hydrogen atom; R 14 represents a hydrogen atom or a group selected from: C 1 -C 6 -alkyl and C 3 -C 6 -cycloalkyl; R 15 and R 16 are independently of each other selected from: hydrogen and C 1 -C 6 -alkyl; or R 15 and R 16 together with the nitrogen atom to which they are attached form a 4- to 6-membered heterocycloalkyl;