A compound of formula I wherein R 1 is selected from the group consisting of a monocyclic or bicyclic group having 5 to 12 ring member atoms of which 4 to 11 ring members are C atoms and 1 to 3 ring members are heteroatoms selected from N and NR N, or 1 or 2 ring members are heteroatoms selected from N and NR N and 1 ring member is selected from O and S, or 1 ring member is N and 2 ring members are independently selected from O and S, with the proviso that no O-O, S-S or S-O bond is formed, wherein the ring member atom attached to the -CH 2 - group in formula I is a N atom, wherein 1 CH 2 ring member attached to a ring member N atom is optionally replaced by a -C(=O)- group, wherein the monocyclic or bicyclic group is saturated or partially unsaturated, with the proviso that in bicyclic groups the ring attached to the -CH 2 - group in formula I must not be aromatic, and wherein the bicyclic group may be a fused, bridged or spiro ring system; wherein any of these groups is optionally and independently substituted with 1 to 3 R 2 groups; R 2 is selected from the group consisting of F, Cl, Br, I, C 1-4 -alkyl, NC-, HO-C 1-4 -alkyl, HO-, C 1-4 -alkyl-O-, C 1-4 -alkyl-O-C 1-4 -alkyl, C 1-4 -alkyl-S-, C 1-4 -alkyl-S(=O)-, C 1-4 -alkyl-S(=O) 2 -, C 3-6 -cycloalkyl-, and C 3-6 -cycloalkyl-O-, wherein any alkyl and cycloalkyl group or submoiety is optionally substituted with 1 to 3 F atoms; and R N is selected from the group consisting of H, C 1-4 -alkyl-, C 1-4 -alkyl-C -, and C 1-4 -alkyl-O-C -; wherein in any definition mentioned hereinbefore and if not specified otherwise, any alkyl group or sub-group may be straight-chained or branched, or a salt thereof. R 1 is selected from the group consisting of a monocyclic or bicyclic group having 5 to 12 ring member atoms of which 4 to 11 ring members are C atoms and 1 to 3 ring members are heteroatoms selected from N and NR N, or 1 or 2 ring members are heteroatoms selected from N and NR N and 1 ring member is selected from O and S, or 1 ring member is N and 2 ring members are independently selected from O and S, with the proviso that no O-O, S-S or S-O bond is formed, wherein the ring member atom attached to the -CH 2 - group in formula I is a N atom, wherein 1 CH 2 ring member attached to a ring member N atom is optionally replaced by a -C(=O)- group, wherein the monocyclic or bicyclic group is saturated or partially unsaturated, with the proviso that in bicyclic groups the ring attached to the -CH 2 - group in formula I must not be aromatic, and wherein the bicyclic group may be a fused, bridged or spiro ring system; wherein any of these groups is optionally and independently substituted with 1 to 3 R 2 groups; wherein the ring member atom attached to the -CH 2 - group in formula I is a N atom, wherein 1 CH 2 ring member attached to a ring member N atom is optionally replaced by a -C(=O)- group, wherein the monocyclic or bicyclic group is saturated or partially unsaturated, with the proviso that in bicyclic groups the ring attached to the -CH 2 - group in formula I must not be aromatic, and wherein the bicyclic group may be a fused, bridged or spiro ring system; R 2 is selected from the group consisting of F, Cl, Br, I, C 1-4 -alkyl, NC-, HO-C 1-4 -alkyl, HO-, C 1-4 -alkyl-O-, C 1-4 -alkyl-O-C 1-4 -alkyl, C 1-4 -alkyl-S-, C 1-4 -alkyl-S(=O)-, C 1-4 -alkyl-S(=O) 2 -, C 3-6 -cycloalkyl-, and C 3-6 -cycloalkyl-O-, wherein any alkyl and cycloalkyl group or submoiety is optionally substituted with 1 to 3 F atoms; and R N is selected from the group consisting of H, C 1-4 -alkyl-, C 1-4 -alkyl-C -, and C 1-4 -alkyl-O-C -;