A compound of formula I wherein R 1, R 2 independently of each other are selected from the group consisting of H, C 1-6 -alkyl and C 3-7 -cycloalkyl, while the alkyl or cycloalkyl group may be mono- or polysubstituted by identical or different groups R 11, and a -CH 2 - group in position 3 or 4 of a 5-, 6- or 7-membered cycloalkyl group may be replaced by -O-, -S-, -S(=O)-, -S(=O) 2 - or -NR 12 -; or R 1 and R 2 are linked to each other and together form a group which is selected from the group consisting of a C 3-6 -alkylene bridge, wherein a -CH 2 - group not adjacent to the N atom of the R 1 R 2 N- group may be replaced by -O-, -S-, -S(=O)-, -S(=O) 2 - or -NR 12 -, and wherein one or more H atoms of the alkylene bridge may be replaced by identical or different groups R 11; or R 1 and R 2 are linked to each other such that the R 1 R 2 N- group forms a bridged cyclic ring system with 5 to 8 C-atoms wherein one or more H atoms of the bridged cyclic ring system may be replaced by identical or different groups R 11; and L 1, L 2 independently of each other are selected from the group consisting of H and C 1-3 -alkyl, or L 1 and L 2 are linked to each other and together form a group which is selected from the group consisting of a C 2-5 -alkylene bridge; and U is selected from the group consisting of CH and N; and B is selected from the group consisting of phenyl and pyridinyl each of which may be mono- or polysubstituted by identical or different substituents R 20; and R 11 is selected from the group consisting of OH, F, Cl, Br, CN, C 1-6 -alkyl, C 3-6 -cycloalkyl, C 1-4 -alkyl-O- and R 13 R 14 N-, while each of the above mentioned alkyl or cycloalkyl groups may be substituted independently of one another by one or more substituents selected from F, Cl, Br, OH, CN, CF 3, C 1-3 -alkyl, C 1-3 -alkyl-O- and HO-C 1-3 -alkyl; and R 12 is selected from the group consisting of H, C 1-4 -alkyl and C 1-4 -alkyl-C(=O)-; and R 13, R 14 independently of each other are selected from the group consisting of H and C 1-4 -alkyl; and R 20 is selected from the group consisting of F, Cl, Br, OH, CN, NO 2, C 1-4 -alkyl and C 1-4 -alkyl-O-, wherein each alkyl group may be substituted with one or more substituents independently of each other selected from F, Cl, Br, OH, CN, NO 2 and C 1 - 4 -alkyl-O-; and while, unless otherwise stated, the above-mentioned alkyl groups may be straight-chain or branched, or a salt thereof or a solvate or hydrate thereof. R 1, R 2 independently of each other are selected from the group consisting of H, C 1-6 -alkyl and C 3-7 -cycloalkyl, while the alkyl or cycloalkyl group may be mono- or polysubstituted by identical or different groups R 11, and a -CH 2 - group in position 3 or 4 of a 5-, 6- or 7-membered cycloalkyl group may be replaced by -O-, -S-, -S(=O)-, -S(=O) 2 - or -NR 12 -; or R 1 and R 2 are linked to each other and together form a group which is selected from the group consisting of a C 3-6 -alkylene bridge, wherein a -CH 2 - group not adjacent to the N atom of the R 1 R 2 N- group may be replaced by -O-, -S-, -S(=O)-, -S(=O) 2 - or -NR 12 -, and wherein one or more H atoms of the alkylene bridge may be replaced by identical or different groups R 11; or R 1 and R 2 are linked to each other such that the R 1 R 2 N- group forms a bridged cyclic ring system with 5 to 8 C-atoms wherein one or more H atoms of the bridged cyclic ring system may be replaced by identical or different groups R 11; and L 1, L 2 independently of each other are selected from the group consisting of H and C 1-3 -alkyl, or L 1 and L 2 are linked to each other and together form a group which is selected from the group consisting of a C 2-5 -alkylene bridge; and U is selected from the group consisting of CH and N; and B is selected from the group consisting of phenyl and pyridinyl each of which may be mono- or polysubstituted by identical or different substituents R 20; and R 11 is selected from the group consisting of OH, F, Cl, Br, CN, C 1-6 -alkyl, C 3-6 -cycloalkyl, C 1-4 -alkyl-O- and R 13 R 14 N-, while each of the above mentioned alkyl or cycloalkyl groups may be substituted independently of one another by one or more substituents selected from F, Cl, Br, OH, CN, CF 3, C 1-3 -alkyl, C 1-3 -alkyl-O- and HO-C 1-3 -alkyl; and R 12 is selected from the group consisting of H, C 1-4 -alkyl and C 1-4 -alkyl-C(=O)-; and R 13, R 14 independently of each other are selected from the group consisting of H and C 1-4 -alkyl; and R 20 is selected from the group consisting of F, Cl, Br, OH, CN, NO 2, C 1-4 -alkyl and C 1-4 -alkyl-O-, wherein each alkyl group may be substituted with one or more substituents independently of each other selected from F, Cl, Br, OH, CN, NO 2 and C 1 - 4 -alkyl-O-; and