3,3-difluoropiperidine carbamate heterocyclic compounds as nr2b nmda receptor antagonists

A chemical entity, which is a compound of formula I:

• wherein:
• R1 is alkyl, cycloalkyl, (cycloalkyl)alkyl, heterocyclyl, (heterocyclyl)alkyl, aryl, (aryl)alkyl, heteroaryl or (heteroaryl)alkyl,
• wherein each of cycloalkyl, (cycloalkyl)alkyl, heterocyclyl, (heterocyclyl)alkyl, aryl, (aryl)alkyl, heteroaryl and (heteroaryl)alkyl is independently optionally substituted with 1 to 3 groups independently selected from —F, —Cl, C1-C4 alkyl, cyclopropyl, —C≡CH, —CFH2, —CF2H, —CF3, —CF2CH3, —CH2CF3, C1-C4 alkoxy, —OCFH2, —OCF2H, —OCF3, —CN, —N(R2)(R3), —NO2, C1-C4 alkylthio, C1-C4alkylsulfonyl and —S(O)2CF3;
• wherein each instance of R2 and R3 independently is —H or C1-C4 alkyl, or —N(R2)(R3) is
• Z is 5- or 6-membered monocyclic or 9- or 10-membered bicyclic heteroaryl having ring carbon atoms, 1 nitrogen ring atom and 0-3 additional ring heteroatoms independently selected from N, O and S, which is optionally substituted with 1 or 2 Rx groups and optionally substituted with 1 Ra group, wherein each Rx is attached to a ring carbon atom and Ra is attached to a ring nitrogen atom;
• wherein:
• each instance of Rx independently is —F, —Cl, —CH3, —CFH2, —CF2H, —CF3, —OH, —OCH3, —OCF3 or —CN;
• and
• Ra is C1-4 alkyl, C3-4 cycloalkyl or —S(O)2—C1-4 alkyl.