Factor XIIA inhibitors

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

• wherein
• Y is selected from the group consisting of:
• X is a bond, —C(O)NH—, —C(O)O— or —C(O)—;
• L-(CRcRd)n— is selected from the group consisting of:
• a bond, CH2, —NH—, —NHCH2—, —NH(CH2)2—, —NH(CH2)3—, —N(Me)—, —N(C(O)Me)CH2—, —NHC(O)—, —NHC(O)CH2—, —NHC(O)(CH2)2—, or NHC(O)(CH2)3;
• Ar is a substituted or unsubstituted 9 to 10 membered bicyclic heteroaromatic ring, wherein the bicyclic heteroaromatic ring is an aromatic hydrocarbon ring with at least one heteroatom within the ring selected from the group consisting of O, N and S or a bicyclic ring which is not completely aromatic but contains an aromatic ring, wherein the at least one heteroatom is present within the aromatic ring or the non-aromatic ring, and wherein, when substituted, the Ar is substituted with 1, 2, or 3 substituents selected from the group consisting of:
• halo, C1-6 alkyl, —ORg, —NRgRh or C1-4 alkyl substituted by —NRgRh;
• m is selected from the group consisting of 1, 2, or 3;
• n is 0, 1, 2, 3, or 4;
• o is 1 or 2;
• R1 is selected from the group consisting of substituted or unsubstituted:
• —NR8R9, 5 to 10 membered carbocyclic ring or a 5 to 10 membered heterocyclic ring;
• wherein when substituted R1 is substituted with 1, 2, or 3 groups selected from the group consisting of:
• ═O, CN, —OH, or —O—C1-6 alkyl, halo, C1-6 alkyl or C1-6 haloalkyl;
• R1a and R1b taken together form a substituted or unsubstituted:
• 5 or 6 membered heteroaromatic ring or a phenyl ring;
• wherein, when the ring formed from R1a and R1b is substituted, it is substituted with 1, 2, or 3 Rz groups, wherein Rz is independently selected at each occurrence from:
• ═O, CN, —OH, —O—C1-6 alkyl, halo and C1-6 alkyl;
• R2 is H, C1-6 alkyl, C1-6 haloalkyl, phenyl, benzyl, —C(O)R2a, and S(O)2R2a;
• and
• wherein R2a is selected from the group consisting of:
• C1-6 alkyl, phenyl, or benzyl;
• R3a is H or C1-6 alkyl;
• and
• R4 is ═CH2, —CN, halo, C1-4 alkyl, C1-4 haloalkyl, —OR10, —NR10R11, 6 to 10 membered aryl, C3-8 cycloalkyl, 3 to 6 membered heterocycloalkyl, or 5 to 10 membered heteroaryl, wherein the C3.8 cycloalkyl, 3 to 6 membered heterocycloalkyl, 6 to 10 membered aryl, or 5 to 10 membered heteroaryl group is unsubstituted or substituted with 1, 2 or 3 R12;
• R4a is H, —OH, halo or C1-4 alkyl;
• R5 is H or C1-6 alkyl;
• R8 and R9 are independently selected from the group consisting of:
• H, C1-6 alkyl, C3-6 cycloalkyl, phenyl, C1-4 alkyl substituted with —ORi, or C1-4 alkyl substituted with phenyl, or R8 and R9 taken together with the atom to which they are attached form 3 to 8 membered heterocycloalkyl ring, which is unsubstituted or substituted with:
• CN, halo, C1-6 alkyl or —ORi;
• R12 is independently at each occurrence selected from the group consisting of:
• halo, C1-4 alkyl, C1-4 haloalkyl, —OR13, —CN, —C(O)R10, ═O, SO2R10, benzyl, phenyl, unsubstituted 5 or 6 membered heteroaryl, or methyl substituted 5 or 6 membered heteroaryl;
• R10 and R11 are independently at each occurrence selected from the group consisting of:
• H or C1-4 alkyl;
• R13 is H, C1-4 alkyl, C1-4 haloalkyl, phenyl or benzyl;
• Ra and Rb are independently at each occurrence selected from the group consisting of:
• H, C1-4 alkyl, and —ORj;
• and
• Re, Rf, R9, Rh, Ri and Rj are independently at each occurrence selected from the group consisting of:
• H or C1-4 alkyl.