Spiropiperidine allosteric modulators of nicotinic acetylcholine receptors

A compound having the formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• W is aryl or 6-14 membered heteroaryl ring, wherein W is substituted with 0, 1, 2, or 3 R3 substituents each independently selected from OH, oxo, NR6R7, CN, O(C1-C6)alkyl, halogen, (C1-C6)haloalkyl, aminoalkyl, hydroxyalkyl, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl, wherein each R3 is independently substituted with 0, 1, 2, or 3 R5;
• Z is hydrogen, (C1-C6)alkyl, aryl, or heteroaryl, wherein Z is substituted with 0, 1, 2, or 3 R4 substituents each independently selected from OH, oxo, NR6R7, CN, O(C1-C6)alkyl, halogen, (C1-C6)haloalkyl, aminoalkyl, hydroxyalkyl, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl, wherein each R4 is independently substituted with 0, 1, 2, or 3 R5;
• —X—R10 is
• each R2 is independently halogen, (C1-C6)alkyl, O(C1-C6)alkyl, cycloalkyl, or (C1-C6)haloalkyl;
• or two R2 when both are (C1-C4)alkyl and are attached to the same carbon atom, may join to form a cyclopropyl, cyclobutyl, or cyclopentyl ring or, two R2 when both are (C1-C4)alkyl and are attached to different carbon atoms, may join to form a bridged ring, wherein said cyclopropyl, cyclobutyl, cyclopentyl or bridged ring may be optionally substituted with 0, 1, 2, or 3 substituents independently selected from OH, halogen, or (C1-C4)alkyl;
• each R1 is independently halogen, (C1-C6)alkyl, O(C1-C6)alkyl, or (C1-C6)haloalkyl;
• or, two R1 when both are (C1-C4)alkyl may join to form a cyclopropyl, cyclobutyl, cyclopentyl, or cyclohexyl ring and said ring is substituted with 0, 1, 2, or 3 substituents independently selected from OH, halogen, or (C1-C4)alkyl;
• each R5 is independently selected from halogen, OH, oxo, CF3, OCF3, CN, (C1-C6)alkyl, O(C1-C6)alkyl, S(C1-C4)alkyl, C═O(C1-C4)alkyl, NR8R9, (C═O)NR6R7, (C═O)OR6, (C2-C4)alkenyl, (C2-C4)alkynyl, (C3-C6)cycloalkyl, O(C3-C6)cycloalkyl, C═O(C3-C6)cycloalkyl, aryl, O-aryl, heteroaryl and heterocyclyl;
• each R6 is independently hydrogen or (C1-C4)alkyl;
• each R7 is independently hydrogen or (C1-C4)alkyl;
• each R8 is independently (C1-C4)alkyl, heterocyclyl, cycloalkyl, heteroaryl, aryl, or (C═O)R6, each substituted with 0, 1, 2, or 3 substituents independently selected from halogen, (C1-C4)alkyl, and OH;
• and
• each R9 is independently (C1-C4)alkyl, heterocyclyl, cycloalkyl, heteroaryl, aryl, or (C═O)R6,
• each substituted with 0, 1, 2, or 3 substituents independently selected from halogen, (C1-C4)alkyl, and OH.