Heteroarylsulfonyl-substituted pyridines and their use in the treatment of cancer

A compound of formula I

• or a pharmaceutically acceptable salt thereof, wherein:
• L represents —S(O)n—;
• n represents 2 or 1;
• X represents a heteroaryl group, attached to L via a carbon atom, optionally substituted by one or more groups independently selected from Y;
• R1, R2 and R3 each independently represent H, halo, Ra1, —CN, -Aa1-C(Qa1)Rb1, -Ab1-C(Qb1)N(Rc1)Rd1, -Ac1-C(Qc1)ORe1, -Ad1-S(O)pRf1, -Ae1-S(O)pN(Rg1)Rh1, -Af1-S(O)pORi1, —N3, —N(Rj1)Rk1, —N(H)CN, —NO2, —ONO2, —ORl1 or —SRm1;
• each Aa1 to Af1 independently represents a single bond, —N(Rp1)— or —O—;
• each Qa1 to Qc1 independently represents ═O, ═S, ═NRn1 or ═N(ORo1);
• each Ra1 and Rf1 independently represents C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more groups independently selected from G1a, heterocyclyl optionally substituted by one or more groups independently selected from G1b, aryl optionally substituted by one or more groups independently selected from G1c, or heteroaryl optionally substituted by one or more groups independently selected from G1d;
• each Rb1, Rc1, Rd1, Re1, Rg1, Rh1, Ri1, Rj1, Rk1, Rl1, Rm1, Rn1, Ro1 and Rp1 independently represents H, C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more groups independently selected from G1a, heterocyclyl optionally substituted by one or more groups independently selected from G1b, aryl optionally substituted by one or more groups independently selected from G1c, or heteroaryl optionally substituted by one or more groups independently selected from G1d;
• any of Rc1 and Rd1, Rg1 and Rh1 and/or Rj1 and Rk1 are linked together to form, together with the nitrogen atom to which they are attached, a 3-to 6-membered ring, which ring optionally contains one further heteroatom and which ring optionally is substituted by one or more groups independently selected from halo, and C1-3 alkyl, C2-3 alkenyl or C2-3 alkynyl each optionally substituted by one or more halo, and ═O;
• each G1a and G1b independently represents halo, —CN, —N(Ra2)Rb2, —ORc2, —SRd2 or ═O;
• each G1c and G1d independently represents halo, —CN, —N(Ra2)Rb2, —ORc2 or —SRd2;
• each Ra2, Rb2, Rc2 and Rd2 independently represents H or C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more fluoro;
• or
• Ra2 and Rb2 are linked together to form, along with the nitrogen atom to which they are attached, a 3- to 6-membered ring, which ring optionally contains one further heteroatom and which ring optionally is substituted by one or more groups independently selected from fluoro, C1-3 alkyl, C2-3 alkenyl or C2-3 alkynyl each optionally substituted by one or more fluoro;
• each Y independently represents halo, Ra3, —CN, -Aa2-C(Qa2)Rb3, -Ab2-C(Qb2)N(Rc3)Rd3, -Ac2-C(Qc2)ORe3, -Ad2-S(O)qRf3, -Ae2-S(O)qN(Rg3)Rh3, -Af2-S(O)qORi3, —N3, —N(Rj3)Rk3, —N(H)CN, —ONO2, —OR13 or —SRm3;
• each Qa2 to Qc2 independently represents ═O, ═S, ═NRn3 or ═N(ORo3);
• each Aa2 to Ar2 independently represents a single bond, —N(Rp3)— or —O—;
• each Ra3 and Rf1 independently represents C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more groups independently selected from G2a, heterocyclyl optionally substituted by one or more groups independently selected from G2b, aryl optionally substituted by one or more groups independently selected from G2c, or heteroaryl optionally substituted by one or more groups independently selected from G2d;
• each Rb3, Rc3, Rd3, Re3, Rg3, Rh3Ri3, Rj3, Rk3, Rl3, Rm3, Rn3, Ro3 and Rp3 independently represents H, C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more groups independently selected from G2a, heterocyclyl optionally substituted by one or more groups independently selected from G2b, aryl optionally substituted by one or more groups independently selected from G2c, or heteroaryl optionally substituted by one or more groups independently selected from G2d;
• or
• any two Rc3 and Rd3, Rg3 and Rh3 and/or Rj3 and Rk3 are linked together to form, along with the nitrogen atom to which they are attached, a 3-to 6-membered ring, which ring optionally contains one further heteroatom and which ring optionally is substituted by one or more groups independently selected from heterocyclyl optionally substituted by one or more groups independently selected from G2b, aryl optionally substituted by one or more groups independently selected from G2c, or heteroaryl optionally substituted by one or more groups independently selected from G2d, and ═O;
• each G2a independently represents halo, —CN, —N(Rj4)Rk4, —ORl4, —SRm4 or ═O;
• each G2b independently represents halo, Ra4, —CN, —N(Rj4)Rk4, —ORl4, —SRm4 or ═O;
• each G2C and G2d independently represents halo, Ra4, —CN, -Aa3-C(Qa3)Rb4, -Ab3-C(Qb3)N(Rc4)Rd4, -Ac3-C(Qc3)ORe4, -Ad3-S(O)qRf4, -Ae3-S(O)qN(Rg4)Rh4, -Af3-S(O)qOR14, —N3, —N(Rj4)Rk4, —N(H)CN, —NO2, —ONO2, —OR14 or —SRm4;
• each Qa3 to Qc3 independently represents ═O, ═S, ═NRn4 or ═N(ORo4);
• each Aa3 to A13 independently represents a single bond, —N(Rp4)— or —O—;
• each Ra4 and Rf4 independently represents C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more groups independently selected from G3a, heterocyclyl optionally substituted by one or more groups independently selected from G3b, aryl optionally substituted by one or more groups independently selected from G3c, or heteroaryl optionally substituted by one or more groups independently selected from G3d;
• each Rb4, Rc4, Rd4, Re4, Rg4, Rh4, Ri4, Rj4, Rk4, Rl4, Rm4, Rn4, Ro4 and Rp4 independently represents H, C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more groups independently selected from G3a or heterocyclyl optionally substituted by one or more groups independently selected from G3b, aryl optionally substituted by one or more groups independently selected from G3c, or heteroaryl optionally substituted by one or more groups independently selected from G3d;
• or
• any of Rc4 and Rd4, Rg4 and Rh4 and/or Rj4 and Rk4 are linked together to form, together with the nitrogen atom to which they are attached, a 3-to 6-membered ring, which ring optionally contains one further heteroatom and which ring optionally is substituted by one or more groups independently selected G3b;
• each G3a and G3b independently represents halo, Ra5, —CN, —N(Rb5)Rc5, —ORd5, —SRe5 or ═O;
• each Ra5 independently represents C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more groups independently selected from G4;
• each Rb5, Rc5, Rd5 and Re5 independently represents H, or C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more groups independently selected from G4;
• or
• each Rb5 and Rc5 are linked together to form, together with the nitrogen atom to which they are attached, a 3- to 6-membered ring, which ring optionally contains one further heteroatom and which ring optionally is substituted by one or more groups independently selected from G4;
• each G4 independently represents halo, Ra6, —CN, —N(Rb6)Rc6, —ORd6 or ═O;
• each Ra6 independently represents C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more fluoro;
• each Rb6, Rc6 and Rd6 independently represents H, or C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl each optionally substituted by one or more fluoro;
• and
• each p and q independently represents 1 or 2,
• with the provisos that the compound of formula I does not represent:
• 3-nitro-2-(pyridin-2-ylsulfonyl)pyridine,
• 2-((3-nitropyridin-2-yl)sulfonyl)pyrimidine, or
• N-(6-chloro-2-((5-chloro-3-nitropyridin-2-yl)sulfonyl)pyridin-3-yl)acetamide.