Compound of the formula (I) ** Formula ** in which R 1 represents C 1 -C 6 alkyl or C 3 -C 5 cycloalkyl, where alkyl is substituted with 1 to 2 substituents, independently selected from the group consisting of hydroxy, alkoxy C1-C4 and haloalkoxy, and R2 represents hydrogen or C1-C4 alkyl, or R1 and R2 together with the nitrogen atom to which they are attached form a 4- to 7-membered N-heterocycle, the N-heterocycle may be substituted with 1 to 3 substituents, independently selected from each other from the group consisting of oxo, hydroxy, monofluoromethyl, difluoromethyl, trifluoromethyl, hydroxycarbonyl, tert-butoxycarbonyl, aminocarbonyl, C1-C4 alkyl, C1-C4 alkoxy, C1-C4 alkoxy-C1-alkyl C4, halogen and hydroxyalkyl or the N-heterocycle may have two substituents, which together with the carbon atom of the N-heterocycle to which they are attached together form a 4- to 6-membered heterocycle, where this heterocycle may be in turn substitute with 1 to 3 substituents, independently selected from the group consisting of oxo, methyl and ethyl, R3 represents hydrogen, fluorine, methoxy or ethoxy, and R4 represents hydrogen, fluorine, methoxy or ethoxy, and its salts, its solvates and the solvates of their salts.Compuesto de la fórmula (I) **Fórmula** en la que R1 representa alquilo C1-C6 o cicloalquilo C3-C5, donde alquilo está sustituido con 1 a 2 sustituyentes, seleccionados independientemente entre sí del grupo que se compone de hidroxi, alcoxi C1-C4 y haloalcoxi, y R2 representa hidrógeno o alquilo C1-C4, o R1 y R2 junto con el átomo de nitrógeno al que están unidos forman un N-heterociclo de 4 a 7 miembros, pudiendo estar el N-heterociclo sustituido con 1 a 3 sustituyentes, seleccionados independientemente entre sí del grupo que se compone de oxo, hidroxi, monofluorometilo, difluorometilo, trifluorometilo, hidroxicarbonilo, terc-butoxicarbonilo, aminocarbonilo, alquilo C1-C4, alcoxi C1-C4, alcoxi C1-C4-alquilo C1-C4, halógeno e hidroxialquilo o pudiendo presentar e
