Imidazopyridine derivatives as inhibitors of receptor tyrosine kinases

A compound of formula (I):

• wherein
• R2 represents C1-6 alkyl or halo C1-6 alkyl;
• A is a group Ad which represents a phenyl group which may be optionally substituted by one or more (e.g. 1, 2 or 3) Ra groups;
• R3 represents hydrogen or C1-6 alkyl;
• R4 is a group R4c;
• R4c is selected from any one of (a)-(f), which represent:
• (a) pyridazinyl optionally substituted by one or more (e.g. 1, 2 or 3) Re groups, or two or more (e.g. 2, 3 or 4) Rb groups;
• (b) pyrazinyl optionally substituted by one or more (e.g. 1, 2 or 3) Rb groups;
• (c) triazinyl optionally substituted by one or two Rb groups;
• (d) pyrimidin-2-yl optionally substituted by one or more (e.g. 1, 2 or 3) Rb groups;
• (e) pyrimidin-4-yl optionally substituted by one or more (e.g. 1, 2 or 3) Rg groups or two or more (e.g. 2, 3 or 4) Rb groups;
• (f) pyrimidin-5-yl optionally substituted by one or more (e.g. 1, 2 or 3) RP groups or two or more (e.g. 2, 3 or 4) Rb groups;
• Rw, Rx, Ry and Rz independently represent hydrogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 alkanol, —COOC1-6 alkyl, hydroxy, C1-6 alkoxy, haloC1-6 alkyl, —(CH2)n—O—C1-6 alkyl, —CO—-(CH2)n—C1-6 alkoxy, C1-6 alkylamino, —C1-6 alkyl-N(C1-6 alkyl)2, —C1-6 alkyl-NH(C1-6 alkyl), C3-8 cycloalkyl or C3-8 cycloalkenyl or when attached to a nitrogen atom, Rw, Rx, Ry and Rz may form a ring;
• Ra represents halogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-8 cycloalkyl, C3-8 cycloalkenyl, —ORx, —(CH2)n—O—C1-6 alkyl, —O—(CH2)n—ORx, haloC1-6 alkyl, haloC1-6 alkoxy, C1-6 alkanol, ═O, ═S, nitro, Si(Rx)4, —(CH2)s—CN, —S—Rx, —SO—Rx, —SO2—Rx, —CORx, —(CRxRy)s—COORz, —(CRxRy)s—CONRwRz, —(CH2)s—CONRxRy, —(CH2)s—NRxRy, —(CH2)s—NRxCORy, —(CH2)s—NRxSO2—Ry, —(CH2)s—NH—SO2—NRxRy, —OCONRxRy,—(CH2)s—NRxCO2Ry,—O—(CH2)2—NRxRy,—O—(CH2)s—CRxRy—(CH2)t—ORzor —(CH2)s—SO2NRxRygroups;
• Rb represents an Ra group or a -Y-heterocyclyl group wherein said heterocyclyl group may be optionally substituted by one or more (e.g. 1, 2 or 3) Ra groups;
• Y represents a bond, —CO—(CH2)s—, —(CRxRy)s—CO—, —COO—,—(CH2)n —(CRxRy)s—, —NRx—(CH2)s—, —(CH2)s—NRx—, —CONRx—, —NRxCO—, —SO2NRx—, —NRxSO2—, —NRxCONRy—, —NRxCSNRy—, —O—(CH2)s—, —(CH2)s—O—, —S—, —SO— or —(CH2)s—SO2—;
• Re represents halogen, C2-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-8 cycloalkyl, C3-8 cycloalkenyl, —ORx, —(CH2)n—O—C1-6 alkyl, —O—(CH2)n—ORx, haloC1-6 alkyl, haloC1-6 alkoxy, C1-6 alkanol, ═O, ═S, nitro, Si(Rx)4, —(CH2)s—CN, —S—Rx, —SO—Rx, —SO2—Rx, —CORx, —(CRxRy)s—COORz, —(CRxRy)s—CONRwRz, —(CH2)s—CONRxRy, —(CH2)s—NRxRy, —(CH2)s—NRxCORy, —(CH2)s—NRxSO2—Ry, —(CH2)s—NH—SO2—NRxRy, —OCONRxRy, —(CH2)s—NRxCO2Ry, —O—(CH2)s—CRxRy—(CH2)t—ORz or —(CH2)s—SO2NRxRy groups, or a —Y-heterocyclyl group wherein said heterocyclyl group may be optionally substituted by one or more (e.g. 1, 2 or 3) Ra groups;
• Rg represents halogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-8 cycloalkyl, C3-8 cycloalkenyl, —ORx, —(CH2)n—O—C1-6 alkyl, —O —(CH2)n—ORx, haloC1-6 alkyl, haloC1-6 alkoxy, C1-6 alkanol, ═O, ═S, nitro, Si(Rx)4, —(CH2)s—CN, —S—Rx, —SO—Rx, —SO2—Rx, —CORx, —(CRxRy)s—COORz, —(CRxRy)s—CONRwRz, —(CH2)s—CONRxRy, —(CH2)s—NHC1-6 alkyl, —(CH2)s—N(C1-6 alkyl)2, —(CH2)n—NRxRy, —(CH2)s—NRxCORy, —(CH2)s—NRxSO2—Ry, —(CH2)s—NH-SO2—NRxRy, —OCONRxRy,—(CH2)s—NRxCO2Ry, —O—(CH2)s—CRxRy—(CH2)t—ORz or —(CH2)s—SO2NRxRy groups, or a —Y-heterocyclyl group wherein said heterocyclyl group may be optionally substituted by one or more (e.g. 1, 2 or 3) Ra groups;
• Rprepresents halogen, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-8 cycloalkyl, C3-8 cycloalkenyl, —ORx, —(CH2)n—O—C1-6 alkyl, —O—(CH2)n—ORx, haloC1-6 alkyl, haloC1-6 alkoxy, C1-6 alkanol, ═O, ═S, nitro, Si(Rx)4, —(CH2)s—CN, —S—Rx, —SO—Rx, —SO2—Rx, —CORx, —(CRxRy)s—COORz, —(CRxRy)s—CONRwRz, —(CH2)s—CONRxRy, —(CH2)s—NRxRy, —(CH2)s—NRxCORy, —(CH2)s—NRxSO2—Ry, —(CH2)s—NH—SO2—NRxRy, —OCONRxRy,—(CH2)s—NRxCO2Ry, —O—(CH2)s—CRxRy—(CH2)t—ORz or —(CH2)s—SO2NRxRygroups;
• a —Y-(4-membered heterocyclyl group) wherein said 4-membered heterocyclyl group is substituted by one or more (e.g. 1, 2 or 3) Ra groups;
• or a —Y-(5-10 membered heterocyclyl group) wherein said 5-10 membered heterocyclyl group may be optionally substituted by one or more (e.g. 1, 2 or 3) Ra groups;
• n represents an integer from 1-4;
• s and t independently represent an integer from 0-4;
• including a pharmaceutically acceptable salt, solvate or tautomer thereof.