Compound of the following general formula (I): ** Formula ** as well as its pharmaceutically acceptable salts, its stereoisomers or mixtures of stereoisomers in any proportion, in particular a mixture of enantiomers, and in particular a racemic mixture, in which: - X represents a (C1-C6) alkyl, phenyl, benzyl, C (O) OR5, or C (O) NHR5 group, - R1 represents a hydrogen atom or a C (O) H, C (O) R6 group, or C (O) OR6, - R2 represents a hydrogen atom or a (C1-C6) alkyl group, or R2 forms with R1 or X a saturated hydrocarbon chain so as to form a 5- or 6-membered ring, in particular 5-membered, - R3 represents a hydrogen atom or a halogen or a (C1-C6) alkyl or (C1-C6) alkoxy group, - R4 represents a hydrogen or halogen atom, CN, NO2, or an alkyl group (C1-C6), (C1-C6) alkoxy, aryloxy, benzyloxy, or heteroaryloxy, said group possibly being substituted with one or more halogen atoms, - Ar represents a thiophene group yl or a phenyl group optionally substituted with one or more halogen atoms, and - R5 and R6 represent, independently of each other, a (C1-C6) alkyl, aryl-(C1-C6) alkyl or aryl group, said group possibly substituted by one or more halogen atoms.Compuesto de fórmula general (I) siguiente:**Fórmula** así como sus sales farmacéuticamente aceptables, sus estereoisómeros o mezclas de estereoisómeros en cualquier proporción, en particular una mezcla de enantiómeros, y en particular una mezcla racémica, en la que: - X representa un grupo alquilo (C1-C6), fenilo, bencilo, C(O)OR5, o C(O)NHR5, - R1 representa un átomo de hidrógeno o un grupo C(O)H, C(O)R6, o C(O)OR6, - R2 representa un átomo de hidrógeno o un grupo alquilo (C1-C6), o R2 forma con R1 o X una cadena hidrocarbonada saturada de manera que se forme un anillo de 5 o 6 miembros, en particular de 5 miembros, - R3 representa un átomo de hidrógeno o un halógeno o un grupo alquilo (C1-C6) o alcoxi (C1-C6), - R4 representa un átomo de hidrógeno o de halógeno, CN, NO2, o un grupo alquilo (C1-C6), alcoxi (C1-C6), ar
