Minor groove binders

A compound of formula I,

• wherein
• the wavy lines indicate optional cis- or trans-stereochemistry;
• wherein
• R1 represents
• H,
• R1aC(O)—NH—,
• NO2 or
• —N(R2a)R2b;
• R1a represents
• aryl (which latter group is optionally substituted by one or more substituents selected from OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy),
• aromatic or part-aromatic C13-14 tricyclic carbocyclyl (which latter group is optionally substituted by one or more substituents selected from OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy, and which latter group, if part-aromatic, is optionally substituted in the non-aromatic part by one or two oxo groups) or
• C1-12 alkyl (which latter group is optionally substituted and/or terminated by one or more substituents selected from halo and aryl (which latter group is optionally substituted by one or more substituents selected from OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy));
• a represents 1, 2, 3 or 4;
• A represents C2-6 alkylene or
• A1-C(O)N(H)-A2, wherein A2 is attached to the group D;
• A1 represents C1-4 alkylene;
• A2 represents C2-5 alkylene;
• D represents Het1, —N(R3a)R3b, —C(═NR3c)N(R3d)R3e or —N(R3f)C(═NR3g)N(H)R3h;
• Het1 represents a four- to twelve-membered heterocyclic group containing at least one N atom and optionally one or more heteroatoms selected from N, O and S, which heterocyclic groups are optionally substituted by one or more substituents selected from ═O, OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy;
• R3a and R3b independently represent H, C1-6 alkyl or Het2;
• R3c to R3h independently represent H or C1-6 alkyl;
• Het2 independently represents a four- to twelve-membered heterocyclic group containing one or more heteroatoms selected from N, O and S, which heterocyclic group is optionally substituted by one or more substituents selected from ═O, OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy;
• each Qa to Qc independently represents, at each occurrence when used herein,
• naphthyl (optionally substituted by one or more substituents selected from OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy),
• Het3,
• or a structural fragment represented by formula Ia, Ib, Ic, Id, Ie or If,
• wherein
• the dashed lines indicate the positions of attachment of the fragments;
• R4 represents H or C1-6 alkyl;
• R5 represents C1-12 alkyl;
• R6, R7, R8 and R9 independently represent H or C1-12 alkyl;
• R10 represents, independently at each occurrence, OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl, —S—C1-4 alkyl and C1-4 alkoxy;
• b represents 0, 1, 2 or 3;
• G1 and G2 independently represent CH or N, or G2 alternatively represents C—R10;
• L represents O or S;
• Het3 represents a nine- or ten-membered, bicyclic heterocyclic group containing one or more heteroatoms selected from N, O and S, which group is optionally substituted by one or more substituents selected from ═O, halo, cyano, nitro, N(R2a)R2b, Heta, C1-4 alkyl and ORa;
• Ra represents H, C1-4 alkyl, aryl (which latter group is optionally substituted by one or more substituents selected from OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy) or Hetb;
• Heta and Hetb independently represent four- to twelve-membered heterocyclic groups containing one or more heteroatoms selected from N, O and S, which heterocyclic groups are optionally substituted by one or more substituents selected from ═O, OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy;
• R11 and R12 independently represent, at each occurrence when used herein, H, C1-6 alkyl or aryl (which latter group is optionally substituted by one or more substituents selected from OH, halo, cyano, nitro, N(R2a)R2b, C1-4 alkyl and C1-4 alkoxy);
• R2a and R2b independently represent, at each occurrence when used herein, H or C1-4 alkyl, or R2a represents —C(O)R13;
• R13 represents H or C1-4 alkyl;
• and
• unless otherwise specified alkyl, alkylene, alkenylene, cycloalkylene, phenylene and naphthylene groups, as well as the alkyl part of alkoxy groups, may be substituted by one or more halo atoms;
• or a pharmaceutically acceptable salt thereof,
• provided that the compound contains at least one Qa or Qb group that is other than a structural fragment represented by formula Ia in which G1 represents CH.