Gsk-3 inhibitors

A compound of formula I

• where:
• R1 is hydrogen, alkyl, (cycloalkyl)alkyl, alkoxyalkyl, (Ar2)alkyl, ((Ar2)cycloalkyl)alkyl, cycloalkyl, (alkyl)cycloalkyl, Ar2, or Ar3;
• or R1 is (adamantyl)alkyl, (oxetanyl)alkyl, (tetrahydropyranyl)alkyl, (benzodioxolanyl)alkyl, oxetanyl, (alkyl)piperidinyl, (pentaalkyl)piperidinyl, alkoxytetrahydrofuranyl, tetrahydropyranyl, dialkyltetrahydropyranyl, (dihalophenyl)pyrazolyl, acetamidopyridinyl, (dialkylamino)alkoxypyridinyl, pyridazinyl, (imidizolyl)phenyl, tetrahydroisoquinolinyl, isoquinolinyl, quinolinyl, or naphthyl;
• R2 is N(R3)(R4), dioxolanyl, (alkyl)dioxolanyl, or tetrahydropyranyl;
• R3 is hydrogen, alkyl, (cycloalkyl)alkyl, cycloalkyl, or is Ar2 is phenyl substituted with 0-3 substituents selected from the group consisting of halo, alkyl, haloalkyl, alkoxy, haloalkoxy;
• R4 is hydrogen or alkyl;
• or N(R3)(R4) taken together is azetdinyl, pyrrolidinyl, piperidinyl, piperazinyl, or morpholinyl, and is substituted with 0-4 substituents selected from alkyl and halo;
• Ar1 is 3-pyridinyl, 3-pyridazinyl, 4-pyridazinyl, 5-pyrimidinyl, or 2-pyrazinyl, and is substituted with 0-3 substituents selected from the group consisting of cyano, halo, alkyl, haloalkyl, (R2)alkyl, alkoxy, haloalkoxy, R2, and Ar2;
• Ar2 is phenyl or pyridinyl and is substituted with 0-3 substituents selected from the group consisting of cyano, halo, alkyl, haloalkyl, alkoxy, haloalkoxy, alkylsulfinyl, alkylsulfonyl, and phenyl that is in turn substituted with 0-3 substituents selected from the group consisting of halo, alkyl, haloalkyl, and alkoxy;
• and
• Ar3 is pyrazolyl, isothiazolyl, imidazolyl, thiadiazolyl, or triazolyl, and is substituted with 0-3 substituents selected from the group consisting of cyano, halo, alkyl, cycloalkyl, haloalkyl, alkoxy, and haloalkoxy;
• or a pharmaceutically acceptable salt thereof.