A compound of general formula wherein R 1 is selected from: - a -(C(R 3) 2) m -aryl group in which the aryl group may be optionally substituted by at least one halogen atom; - a -(C(R 3) 2) m -heteroaryl group in which the heteroaryl group may be optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy or C 1-3 -haloalkyl and in which the heteroaryl group may optionally be condensed with an additional ring system; - a -(C(R 3) 2) n -heterocycloalkyl group, in which the heterocycloalkyl may be optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy or C 1-3 -haloalkyl and contains at least one oxygen atom; R 2 is selected from: - a phenyl group optionally substituted by at least one substitutent selected from a halogen, C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; - a heteroaryl group optionally substituted by at least one substitutent selected from a halogen, C 1-3 -alkyl C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; - a heterocycloalkyl group and being optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; R 3 is H or C 1-3 alkyl; m is 1 to 3; and n is 0 to 3; with the proviso that when R 1 is a -(C(R 3) 2) m -aryl group, R 2 is not a phenyl group; or a pharmaceutically acceptable salt or solvate thereof. R 1 is selected from: - a -(C(R 3) 2) m -aryl group in which the aryl group may be optionally substituted by at least one halogen atom; - a -(C(R 3) 2) m -heteroaryl group in which the heteroaryl group may be optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy or C 1-3 -haloalkyl and in which the heteroaryl group may optionally be condensed with an additional ring system; - a -(C(R 3) 2) n -heterocycloalkyl group, in which the heterocycloalkyl may be optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy or C 1-3 -haloalkyl and contains at least one oxygen atom; - a -(C(R 3) 2) m -aryl group in which the aryl group may be optionally substituted by at least one halogen atom; - a -(C(R 3) 2) m -heteroaryl group in which the heteroaryl group may be optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy or C 1-3 -haloalkyl and in which the heteroaryl group may optionally be condensed with an additional ring system; - a -(C(R 3) 2) n -heterocycloalkyl group, in which the heterocycloalkyl may be optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy or C 1-3 -haloalkyl and contains at least one oxygen atom; R 2 is selected from: - a phenyl group optionally substituted by at least one substitutent selected from a halogen, C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; - a heteroaryl group optionally substituted by at least one substitutent selected from a halogen, C 1-3 -alkyl C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; - a heterocycloalkyl group and being optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; - a phenyl group optionally substituted by at least one substitutent selected from a halogen, C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; - a heteroaryl group optionally substituted by at least one substitutent selected from a halogen, C 1-3 -alkyl C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; - a heterocycloalkyl group and being optionally substituted by at least one substituent selected from a halogen, C 1-3 -alkyl, C 1-3 -alkoxy, C 1-3 -haloalcoxy, C 1-3 -haloalkyl or a hydroxyl group; R 3 is H or C 1-3 alkyl; m is 1 to 3; and n is 0 to 3;