IMIDAZO [1, 2 - B] PYRIDAZINE DERIVATIVES AS CDPK1 INHIBITORS

摘要

A first aspect of the invention relates to a compound of formula (I), or a pharmaceutically acceptable salt or ester thereof, (Formula (I)) wherein: R1 is -(CH2)nNR3R4, -OR5 or -(CH2)n-heterocycloalkyl, wherein said heterocycloalkyl group is optionally substituted by one or more R7 groups; R2 is selected from aryl, heteroaryl, fused aryl-heterocycloalkyl and fused hetero aryl-heterocycloalkyl each of which is substituted by at least one R8 group; R3 is H or alkyl; R4 is: (i) cycloalkyl optionally substituted by one or more -NR11R12 or NHCOR11 groups; or (ii) -(CH2)n-heterocycloalkyl, wherein said heterocycloalkyl is a 4, 5 or 6-membered nitrogen-containing group optionally containing one or more CO groups, wherein said heterocycloalkyl is optionally substituted by one or more one or more (CH2)nR7 groups; or (iii) alkyl substituted by one or more -NR11R12groups; or R3 and R4 are linked together with the nitrogen to which they are attached to form a 4, 5, 6 or 7-membered monocyclic heterocycloalkyl group or a bicyclic heterocyclic group, each of which optionally contains one or two further groups selected from CO, O, N and S, and which is optionally further substituted by one or more R7 groups; R5 is selected from alkyl, -(CH2)n-heteroaryl and - (CH2)n-heterocycloalkyl, wherein said heteroaryl and heterocycloalkyl groups are each optionally substituted by one or more R7 groups; each R8 is independently selected from - NR16R17, -OR17 and -(CH2)nR17 where each R16 is H and each R17 is independently - (CHR10)n-heteroaryl, wherein said heteroaryl group is in turn optionally substituted by one or more R7 groups; each R10, R11 and R12 is independently H or alkyl; or in the case of an - NR11R12 group, R11 and R12 may be linked together with the nitrogen to which they are attached to form a 4, 5, 6 or 7-membered monocyclic or bicyclic heterocycloalkyl group optionally containing one or two further groups selected from CO, O, N and S, and which is optionally further substituted by one or more R7 groups; each m is independently an integer from 1 to 6; and each n is independently an integer from 0 to 6. Further aspects relate to the use of said compounds in the treatment of various therapeutic disorders, and more particularly as inhibitors of PfCDPK1.