Fused thiazole derivatives as kinase inhibitors

A compound of formula (I) or a pharmaceutically acceptable salt thereof:

• wherein,
• —X— represents a group of formula (a), (b), (c), (d), (e), (f), (g) or (h):
• R1 and R2 independently represent hydrogen;
• or C1-6 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl(C1-4alkyl, aryl, aryl(C1-6)alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl-(C1-6)alkyl, heteroaryl or heteroaryl(C1-6)alkyl, any of which groups may be optionally, substituted by one or more substituents;
• or
• R1 and R2, when both are attached to the same carbon atom, represent, when taken together with the carbon atom to which they are both attached, C3-7 cycloalkyl or C3-7 heterocycloalkyl, either of which groups may be optionally substituted by one or more substituents;
• or
• R1 and R2, when attached to adjacent carbon atoms, represent, when taken together with the carbon atoms to which they are attached, C5-7 cycloalkyl, phenyl or heteroaryl, any of which groups may be optionally benzo-fused and/or substituted by one or more substituents;
• R3 and R4 independently represent hydrogen;
• or C1-6 alkyl, C3-7 cycloalkyl, C1-7 cycloalkyl(C1-6)alkyl, aryl, aryl(C1-6)alkyl, aryl(C2-6)alkenyl, aryl(C2-6)alkynyl, biaryl(C1-6)alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl(C1-6)allyl, C3-7 heterocycloalkylcarbonyl, heteroaryl, heteroaryl(C1-6)alkyl, heteroaryl-aryl(C1-6)alkyl or aryl-heteroaryl(C1-6)alkyl, any of which groups may be optionally substituted by one or more substituents;
• or
• R3 and R4, when both are attached to the same carbon atom, represent, when taken together with the carbon atom to which they are both attached, C3-7 cycloalkyl or C3-7 heterocycloalkyl, either of which groups may be optionally substituted by one or more substituents;
• or
• R3, and R4, when attached to adjacent carbon atoms, represent, when taken together with the carbon atoms to which they are attached, C5-7 cycloalkyl, phenyl or heteroaryl, any of which groups may be optionally benzo-fused and/or substituted by one or more substituents;
• and
• R5 and R6 independently represent hydrogen or C1-6 alkyl;
• provided the compound is not:
• 2-(morpholin-4-yl)-5,6-dihydro-1,3-benzothiazol-7(4H)-one;
• 5,5-dimethyl-2-(morpholin-4-yl)-5,6-dihydro-1,3-benzothiazol-7(4H)-one;
• 2-(morpholin-4-yl)-5,6,7,8-tetrahydro-4H-[1,3]thiazolo[5,4-c]azepin-4-one;
• and
• 7,7-dimethyl-2-(morpholin-4-yl)-5,6,7,8-tetrahydro-4H-[1,3]thiazolo[5,4-c]azepin-4-one.

A compound of formula (IIA), or a pharmaceutically acceptable salt thereof:

• wherein
• —X1— represents a group of formula (a) or (e):
• R6 represents hydrogen or C1-6 alkyl;
• R11 represents hydrogen or optionally substituted C2-6 alkyl;
• and
• R12 represents C1-6 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl(C1-6)alkyl, aryl, aryl(C1-6)alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl(C1-6)alkyl, heteroaryl or heteroaryl(C1-6)alkyl, any of which groups may be optionally substituted by one or more substituents;
• or
• R11 and R12, when taken together with the carbon atom to which they are both attached, represent C3-7 cycloalkyl or C3-7 heterocycloalkyl, either of which groups may be optionally substituted by one or more substituents;
• and
• R13 represents hydrogen;
• or C1-6 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl(C1-6)alkyl, aryl, aryl(C1-6)alkyl, aryl(C2-6)alkenyl, aryl(C2-6)alkynyl, biaryl(C1-6)alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl(C1-6)alkyl, C3-7 heterocycloalkylcarbonyl, heteroaryl, heteroaryl(C1-6)alkyl, heteroaryl-aryl(C1-6)alkyl or aryl-heteroaryl(C1-6)alkyl, any of which groups may be optionally substituted by one or more substituents.

The compound of formula (IIB), or a pharmaceutically acceptable salt thereof:

• wherein
• —X1— represents a group of formula (a) or (e):
• R6 represents hydrogen or C1-6 alkyl;
• R21 represents hydrogen or optionally substituted C1-6 alkyl;
• and
• R22 represents hydrogen;
• or C1-6 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl(C1-6)alkyl, aryl, aryl(C1-6)alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl(C1-6)alkyl, heteroaryl or heteroaryl(C1-6)alkyl, any of which groups may be optionally substituted by one or more substituents;
• or
• R21 and R22, when taken together with the carbon atom to which they are both attached, represent C3-7 cycloalkyl or C3-7 heterocycloalkyl, either of which groups may be optionally substituted by one or more substituents;
• and
• R23 represents C1-6 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl(C1-6)alkyl, aryl, aryl(C1-6)alkyl, aryl(C2-6)alkenyl, aryl(C2-6)alkynyl, biaryl(C1-6)alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl(C1-6)alkyl, C3-7 heterocycloalkylcarbonyl, heteroaryl, heteroaryl(C1-6)alkyl, heteroaryl-aryl(C1-6)alkyl or aryl-heteroaryl(C1-6)alkyl, any of which groups may be optionally substituted by one or more substituents.

A compound of formula (IIC), or a pharmaceutically acceptable salt thereof:

• wherein
• —X2— represents a group of formula (b), (c), (d), (f), (g) or (h):
• R5 and R6 independently represent hydrogen or C1-6 alkyl;
• R13 represents hydrogen;
• or C1-6 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl(C1-6)alkyl, aryl, aryl(C1-6)alkyl, aryl(C2-6)alkenyl, aryl(C2-6)alkynyl, biaryl(C1-6)alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl(C1-6)alkyl, C3-7 heterocycloalkylcarbonyl, heteroaryl, heteroaryl(C1-6)alkyl, heteroaryl-aryl(C1-6)alkyl or aryl-heteroaryl(C1-6)alkyl, any of which groups may be optionally substituted by one or more substituents;
• R21 represents hydrogen or optionally substituted C1-6 alkyl;
• and
• R22 represents hydrogen;
• or C1-6 alkyl, C3-7 cycloalkyl, C3-7 cycloalkyl(C1-6)alkyl, aryl, aryl(C1-4alkyl, C3-7 heterocycloalkyl, C3-7 heterocycloalkyl(C1-6)alkyl, heteroaryl or heteroaryl(C1-6)alkyl, any of which groups may be optionally substituted by one or more substituents;
• or
• R21 and R22, when taken together with the carbon atom to which they are both attached, represent C3-7 cycloalkyl or C3-7 heterocycloalkyl, either of which groups may be optionally substituted by one or more substituents.