Antagonists of the muscarinic acetylcholine receptor m4

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

• wherein
• the ring containing W, X, Y and Z is a 6-membered heteroaryl ring containing two or one nitrogen atoms and W, X, Y and Z are independently N or CH;
• R1 is a 5- to 10-membered aromatic ring system optionally containing 1-2 nitrogen atoms and optionally substituted with 1-3 substituents independently selected from the group consisting of halogen, C1-C4 alkyl, C1-C4 haloalkyl, —NHCORe, and C3-C6 cycloalkyl;
• Re is hydrogen or C1-C4 alkyl;
• R4 is C4-C6 alkyl or —(CRbRc)p—Y;
• each Rb is independently hydrogen or C1-C4 alkyl;
• each Rc is independently hydrogen or C1-C4 alkyl;
• p is 0, 1, 2, 3, or 4;
• and
• Y′ is C3-C10 cycloalkyl;
• C3-C8 cycloalkenyl;
• aryl;
• a 5- or 6-membered heteroaryl having 1, 2, or 3 heteroatoms independently selected from N, O, and S;
• or a 5-, 6-, or 7-membered heterocycle having 1, 2, or 3 heteroatoms independently selected from N, O, and S;
• wherein Y′ is unsubstituted or substituted with one or two substituents independently selected from halo and C1-C4 alkyl.