A compound of formula I, wherein: R 1 represents methyl; phenyl optionally substituted by one or more groups selected from halogen, -CN, -C NR a1 R a2, -NR a3 R a4, a 5-membered heteroaryl group, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 alkoxy-C 1-4 alkyl or methylenedioxy, wherein the latter four groups are optionally substituted by one or more fluoro groups; or a 5-9-membered heteroaryl group optionally substituted by one or more groups selected from halogen, -CN, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 alkoxy-C 1-4 alkyl or phenyl, which latter four groups are optionally substituted by one or more fluoro groups; R 2 represents halogen, hydroxy, cyano, -C NR a5 R a6, C 1-4 alkyl, C 1-4 alkoxy or C 1-4 alkoxy-C 1-4 alkyl, wherein the latter three groups are optionally substituted by one or more fluoro groups; n represents 0, 1 or 2; Q 1, Q 2, and Q 3 each represent -C(R 4)- or -N-, wherein a maximum of two of Q 1 to Q 3 represent -N-; R 4 represents H, halogen, C 1-4 alkyl or C 1-4 alkoxy which latter two groups are optionally substituted by one or more fluoro group; X represents -C(R 5)(R 6)-, -O-, -S-, -N(R 7)- or a direct bond; R 5, R 6 and R 7 each independently represent H or C 1-2 alkyl; A represents a direct bond, -O-, C 1-2 alkylene, -C 1-2 alkyleneO-, -OC 1-2 alkylene-, -N C 1-2 alkylene- or -C 1-2 alkyleneN -, which latter five groups are optionally substituted by one or more halo, C 1-2 alkyl or =O groups; R 3 represents a 5-6-membered heteroaryl group, optionally substituted by one or more groups selected from halo, -CN, -NR a9 R a10, -C NR a11 R a12, C 1-4 alkyl, C 1-4 alkoxy or C 1-4 alkoxy-C 1-4 alkyl which latter three groups are optionally substituted by one or more fluoro groups; R a1, R a2, R a3, R a4, R a5, R a6, R a7, R a8, R a9, R a10, R a11 and R a12 each independently represent H or C 1-4 alkyl, which C 1-4 alkyl groups are optionally substituted by one or more fluoro groups; or R a1 and R a2, R a3 and R a4, R a5 and R a6, R a7 and R a8, R a9 and R a10 and R a11 and R a12 may independently be joined together to form, together with the atom to which they are attached, a 4- to 6-membered heterocyclyl ring, which heterocyclyl ring optionally contains one further heteroatom selected from N, O or S. or a pharmaceutically-acceptable salt thereof. R 1 represents methyl; phenyl optionally substituted by one or more groups selected from halogen, -CN, -C NR a1 R a2, -NR a3 R a4, a 5-membered heteroaryl group, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 alkoxy-C 1-4 alkyl or methylenedioxy, wherein the latter four groups are optionally substituted by one or more fluoro groups; or a 5-9-membered heteroaryl group optionally substituted by one or more groups selected from halogen, -CN, C 1-4 alkyl, C 1-4 alkoxy, C 1-4 alkoxy-C 1-4 alkyl or phenyl, which latter four groups are optionally substituted by one or more fluoro groups; R 2 represents halogen, hydroxy, cyano, -C NR a5 R a6, C 1-4 alkyl, C 1-4 alkoxy or C 1-4 alkoxy-C 1-4 alkyl, wherein the latter three groups are optionally substituted by one or more fluoro groups; n represents 0, 1 or 2; Q 1, Q 2, and Q 3 each represent -C(R 4)- or -N-, wherein a maximum of two of Q 1 to Q 3 represent -N-; R 4 represents H, halogen, C 1-4 alkyl or C 1-4 alkoxy which latter two groups are optionally substituted by one or more fluoro group; X represents -C(R 5)(R 6)-, -O-, -S-, -N(R 7)- or a direct bond; R 5, R 6 and R 7 each independently represent H or C 1-2 alkyl; A represents a direct bond, -O-, C 1-2 alkylene, -C 1-2 alkyleneO-, -OC 1-2 alkylene-, -N C 1-2 alkylene- or -C 1-2 alkyleneN -, which latter five groups are optionally substituted by one or more halo, C 1-2 alkyl or =O groups; R 3 represents a 5-6-membered heteroaryl group, optionally substituted by one or more groups selected from halo, -CN, -NR a9 R a10, -C NR a11 R a12, C 1-4 alkyl, C 1-4 alkoxy or C 1-4 alkoxy-C 1-4 alkyl which latter three groups are optionally substituted by one or more fluoro groups; R a1, R a2, R a3, R a4, R a5, R a6, R a7, R a8, R a9, R a10, R a11 and R a12 each independently represent H or C 1-4 alkyl, which C 1-4 alkyl groups are optionally substituted by one or more fluoro groups; or R a1 and R a2, R a3 and R a4, R a5 and R a6, R a7 and R a8, R a9 and R a10 and R a11 and R a12 may independently be joined together to form, together with the atom to which they are attached, a 4- to 6-membered heterocyclyl ring, which heterocyclyl ring optionally contains one further heteroatom selected from N, O or S. or a pharmaceutically-acceptable salt thereof.