A compound of formula: wherein: n is 0 or 1; R 1 is selected from the group consisting of phenyl, naphthalenyl, indolyl and benzodioxolyl, wherein said phenyl, naphthalenyl, indolyl and benzodioxolyl may be substituted by one or more substituents selected from the group consisting of hydroxyl, halogen, cyano, C 1 -C 6 -alkyl, C 1 -C 6 -halogenoalkyl, C 1 -C 6 -alkoxy, C 1 -C 6 -halogenoalkoxy, C 1 -C 6 -hydroxyalkoxy, C 1 -C 6 -alkoxy-C 1 -C 6 -alkoxy, ethynyl, carbamoyl, C 1 -C 6 -alkylcarbamoyl, polyoxyethylenyl, amidoxime and phenoxy; R 3 is a 5- or 6-membered heteroaryl comprising one sulfur atom and optionally one further nitrogen, sulfur or oxygen atom, wherein said 5- or 6-membered heteroaryl may be substituted by one or more substituents selected from the group consisting of halogen, C 1 -C 6 -alkyl, phenyl and pyridyl, wherein said phenyl and pyridyl may be substituted by one or more substituents selected from the group consisting of halogen, C 1 -C 6 -alkyl, phenyl, pyridyl, C 1 -C 6 -aminoalkyl and C 1 -C 6 -alkylcarbamoyl; R 2 is hydrogen, C 1 -C 6 -alkyl or C 3 -C 6 -cycloalkyl; and R 4 is selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, -CH 2 -O-R a4, -CH 2 -C(=O)R b4 and -CH 2 -NH-C(=O)R c4, wherein R a4 is hydrogen or C 1 -C 6 -alkyl, R b4 is hydroxyl, C 1 -C 6 -alkoxy, amino or C 1 -C 6 -alkylcarbonylamino and R c4 is C 1 -C 6 -alkoxy, or R 2 and R 4 form together with the nitrogen and carbon atoms to which they are attached a 5- or 6-membered heteroaryl selected from pyrrolidinyl morpholinyl, thiazolidinyl and piperidinyl; or hydrates, solvates, or salts thereof. n is 0 or 1; R 1 is selected from the group consisting of phenyl, naphthalenyl, indolyl and benzodioxolyl, wherein said phenyl, naphthalenyl, indolyl and benzodioxolyl may be substituted by one or more substituents selected from the group consisting of hydroxyl, halogen, cyano, C 1 -C 6 -alkyl, C 1 -C 6 -halogenoalkyl, C 1 -C 6 -alkoxy, C 1 -C 6 -halogenoalkoxy, C 1 -C 6 -hydroxyalkoxy, C 1 -C 6 -alkoxy-C 1 -C 6 -alkoxy, ethynyl, carbamoyl, C 1 -C 6 -alkylcarbamoyl, polyoxyethylenyl, amidoxime and phenoxy; R 3 is a 5- or 6-membered heteroaryl comprising one sulfur atom and optionally one further nitrogen, sulfur or oxygen atom, wherein said 5- or 6-membered heteroaryl may be substituted by one or more substituents selected from the group consisting of halogen, C 1 -C 6 -alkyl, phenyl and pyridyl, wherein said phenyl and pyridyl may be substituted by one or more substituents selected from the group consisting of halogen, C 1 -C 6 -alkyl, phenyl, pyridyl, C 1 -C 6 -aminoalkyl and C 1 -C 6 -alkylcarbamoyl; R 2 is hydrogen, C 1 -C 6 -alkyl or C 3 -C 6 -cycloalkyl; and R 4 is selected from the group consisting of hydrogen, C 1 -C 6 -alkyl, -CH 2 -O-R a4, -CH 2 -C(=O)R b4 and -CH 2 -NH-C(=O)R c4, wherein R a4 is hydrogen or C 1 -C 6 -alkyl, R b4 is hydroxyl, C 1 -C 6 -alkoxy, amino or C 1 -C 6 -alkylcarbonylamino and R c4 is C 1 -C 6 -alkoxy, or R 2 and R 4 form together with the nitrogen and carbon atoms to which they are attached a 5- or 6-membered heteroaryl selected from pyrrolidinyl morpholinyl, thiazolidinyl and piperidinyl; or hydrates, solvates, or salts thereof.