A compound having formula (I) or a salt or hydrate or solvate thereof wherein: R1 is C 1-4 -alkyl unsubstituted or substituted with MeO; tetrahydropyranyl, tetrahydrofuranyl, oxetanyl, dioxepanyl, pyrrolidinyl or piperidinyl; or pyrrolidinyl or piperidinyl with the nitrogen substituted by methyl, isopropyl, oxetanyl, ethoxycarbonyl, acetyl, or trifluoroacetyl; R2 is a 5-, 6- or 7-membered unsubstituted or substituted ring containing 1 or 2 heteroatoms selected from O or N or an unsubstituted or substituted spirocyclic heterocyclyl group containing 1 to 3 heteroatoms selected from N or O consisting of 4 to 11 ring atoms, the ring or spirocyclic heterocyclyl group being bound in formula (I) by a C=C double bond, and in which ring or spirocyclic heterocyclyl group one N-atom can be substituted by methyl, isopropyl, acetyl, benzyloxycarbonyl, phenyl, oxetanyl or tetrahydropyranyl, and in which one or more C-atoms can be substituted by -methyl or -OH.; R3 or R4 are independently from one another hydrogen; C 1-6 -alkyl, unsubstituted or substituted with one or more F, methoxy, C 3-8 -cycloalkyl unsubstituted or substituted with one or more F; aryl; heteroaryl consisting of 5 to 6 ring atoms; or heterocyclyl selected from the group consisting of oxetanyl, tetrahydropyranyl and pyrrolidinyl, said heterocyclyl being unsubstituted or substituted with C 1-6 -alkyl, acetyl, tetrahydrofuranyl, oxetanyl or hydroxyethylacetyl; or R3 and R4 together with the attached N form a heterocyclyl ring selected from the group consisting of morpholinyl and pyrrolidinyl both unsubstituted or substituted with C 1-6 -alkyl, F, or hydroxyl. R1 is C 1-4 -alkyl unsubstituted or substituted with MeO; tetrahydropyranyl, tetrahydrofuranyl, oxetanyl, dioxepanyl, pyrrolidinyl or piperidinyl; or pyrrolidinyl or piperidinyl with the nitrogen substituted by methyl, isopropyl, oxetanyl, ethoxycarbonyl, acetyl, or trifluoroacetyl; R2 is a 5-, 6- or 7-membered unsubstituted or substituted ring containing 1 or 2 heteroatoms selected from O or N or an unsubstituted or substituted spirocyclic heterocyclyl group containing 1 to 3 heteroatoms selected from N or O consisting of 4 to 11 ring atoms, the ring or spirocyclic heterocyclyl group being bound in formula (I) by a C=C double bond, and in which ring or spirocyclic heterocyclyl group one N-atom can be substituted by methyl, isopropyl, acetyl, benzyloxycarbonyl, phenyl, oxetanyl or tetrahydropyranyl, and in which one or more C-atoms can be substituted by -methyl or -OH.; in which ring or spirocyclic heterocyclyl group one N-atom can be substituted by methyl, isopropyl, acetyl, benzyloxycarbonyl, phenyl, oxetanyl or tetrahydropyranyl, and in which one or more C-atoms can be substituted by -methyl or -OH.; R3 or R4 are independently from one another hydrogen; C 1-6 -alkyl, unsubstituted or substituted with one or more F, methoxy, C 3-8 -cycloalkyl unsubstituted or substituted with one or more F; aryl; heteroaryl consisting of 5 to 6 ring atoms; or heterocyclyl selected from the group consisting of oxetanyl, tetrahydropyranyl and pyrrolidinyl, said heterocyclyl being unsubstituted or substituted with C 1-6 -alkyl, acetyl, tetrahydrofuranyl, oxetanyl or hydroxyethylacetyl; or R3 and R4 together with the attached N form a heterocyclyl ring selected from the group consisting of morpholinyl and pyrrolidinyl both unsubstituted or substituted with C 1-6 -alkyl, F, or hydroxyl. <EOS>