Compound of general formula or a pharmaceutically acceptable salt or thereof wherein R 2 and R 3, independently from each other, are selected from: a) -C 1 -C 6 alkyl, with the proviso that R 2 and R 3 are not both methyl, b) -(CH 2) n -aryl, 4-halo-benzyl or 4-halo-phenyl, c) -(CH 2) n -cycloalkyl, d) -(CH 2) n -heterocycle, e) -(CH 2) n -OR 6, f) -(CH 2) n -CN, g) -(CH 2) n -NR 4 R 5, h) taken together with the nitrogen atom to which they are bound to form a 5-to 8-membered heteromonocycle containing from one to three heteroatoms selected from the group consisting of oxygen and sulphur, or i) taken together with the nitrogen atom to which they are bound to form: (i) a 5- to 8-membered heteromonocycle which is fused to one or two saturated or unsaturated rings or to other heterocycles containing from one to three heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur; or (ii) a halo and/or hydroxy substituted dihydroquinoline; wherein R 4 and R 5, independently from each other, are selected from: a) -H, b) -C 1 -C 6 alkyl, c) -(CH 2) n -aryl, d) -(CH 2) n -cycloalkyl, e) -(CH 2) n -heterocycle, f) -(CH 2) n -OR 6, g) -(CH 2) n -CN, h) taken together with the nitrogen atom to which they are bound to form a 5-to 8-membered heteromonocycle containing from one to three heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur, or j) taken together with the nitrogen atom to which they are bound to form a 5-to 8-membered heteromonocycle which is fused to one or two saturated or unsaturated rings or to other heterocycles containing from one to three heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur; or wherein R 6 is selected from: a) -H, b) -C 1 -C 6 alkyl, c) -(CH 2) n -aryl, d) -(CH 2) n -cycloalkyl, or e) -(CH 2) n -heterocycle,; and wherein n is an integer from 0 to 6. a) -C 1 -C 6 alkyl, with the proviso that R 2 and R 3 are not both methyl, b) -(CH 2) n -aryl, 4-halo-benzyl or 4-halo-phenyl, c) -(CH 2) n -cycloalkyl, d) -(CH 2) n -heterocycle, e) -(CH 2) n -OR 6, f) -(CH 2) n -CN, g) -(CH 2) n -NR 4 R 5, h) taken together with the nitrogen atom to which they are bound to form a 5-to 8-membered heteromonocycle containing from one to three heteroatoms selected from the group consisting of oxygen and sulphur, or i) taken together with the nitrogen atom to which they are bound to form: (i) a 5- to 8-membered heteromonocycle which is fused to one or two saturated or unsaturated rings or to other heterocycles containing from one to three heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur; or (ii) a halo and/or hydroxy substituted dihydroquinoline; a) -H, b) -C 1 -C 6 alkyl, c) -(CH 2) n -aryl, d) -(CH 2) n -cycloalkyl, e) -(CH 2) n -heterocycle, f) -(CH 2) n -OR 6, g) -(CH 2) n -CN, h) taken together with the nitrogen atom to which they are bound to form a 5-to 8-membered heteromonocycle containing from one to three heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur, or j) taken together with the nitrogen atom to which they are bound to form a 5-to 8-membered heteromonocycle which is fused to one or two saturated or unsaturated rings or to other heterocycles containing from one to three heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur; or a) -H, b) -C 1 -C 6 alkyl, c) -(CH 2) n -aryl, d) -(CH 2) n -cycloalkyl, or e) -(CH 2) n -heterocycle,;