Cyclobutyl benzimidazoles as PDE 10 inhibitors

1. A compound of the formula I:

wherein:

each R, and R x independently represent H, OH, halogen, or C 1-6 alkyl,

R c represents H, OH, halogen, —C(R) 2 OR, or C 1-6 alkyl,

R 2 is selected from the group consisting of H, O—R, CN, O(CH 2 ) n OR, OCHR(CH2) n OR, SR, SO 2 R, S(O)R, N(R) 2 , C(O)N(R) 2 , C 1-3 haloalkyl, O(CH 2 ) n C 1-3 haloalkyl, O(CH 2 ) n C 3-6 cycloalkyl, (CH 2 ) n C 5-10 heterocycle, C 1-6 alkyl, and C 3-10 cycloalkyl, said alkyl, cycloalkyl, and heterocycle unsubstituted or substituted with 1 to 3 groups of R a ;

R a is selected from the group consisting of:

(1) halogen,

(2) hydroxyl,

(3) C 1-6 alkyl,

(4) —(CH 2 ) n O—R,

(5) (CH 2 ) n C 6-10 aryl,

(6) (CH 2 ) n C 5-10 heterocycle,

(7) OC 1-5 haloalkyl;

(8) CO 2 R;

(9) C(O)N(R) 2 ;

(10) (CH 2 ) n C(O)R;

(11) CN,

(12) (CH 2 ) n N(R) 2 ;

(13) (CH 2 ) n C 3-6 cycloalkyl,

(14) (CH 2 ) n C 1-3 haloalkyl;

(15) —O—

n represents 0-4,

or a pharmaceutically acceptable salt thereof.

2. The compound according to claim 1 wherein there is one R c selected from —C(R) 2 OR, and C 1-6 alkyl.

3. The compound according to claim 1 wherein there are two R c 's independently selected from hydrogen, —C(R) 2 OR, and C 1-6 alkyl.

4. The compound according to claim 1 wherein there are two R c 's both of which are methyl.

5. The compound according to claim 1 wherein both R x are hydrogen.

6. The compound according to claim 1 wherein one R x is C 1-6 alkyl and the other is hydrogen, one R x is halogen and the other is hydrogen, or one R x is OH and the other is hydrogen.

7. The compound according to claim 1 wherein R is C 1-6 alkyl.

8. The compound according to claim 1 wherein R is methyl.

9. The compound according to claim 1 wherein R 2 is selected from the group consisting of H, O—R, and C 1-6 alkyl, said alkyl unsubstituted or substituted with 1 to 3 groups of R a .

10. The compound according to claim 1 wherein wherein there are two R c 's independently selected from hydrogen, —C(R) 2 OR, and C 1-6 alkyl, both R x 's are hydrogen, one R x is halogen and the other is hydrogen, or one R x is OH and the other is hydrogen, R is C 1-6 alkyl and R 2 is selected from the group consisting of H, O—R, and C 1-6 alkyl.

11. The compound according to claim 10 wherein both R c c's are methy, and R is methyl.

12. The compound according to formula I of claim 1 represented by structural formulas Ia and Iaa:

or pharmaceutically acceptable salts thereof, wherein R, R c , R x and R 2 are as originally described.

13. The compound according of formula I of claim 1 represented by structural formulas Ib and Ibb:

or pharmaceutically acceptable salts thereof, wherein R c , R, and R x are as originally described.

14. The compound according to claim 13 wherein R c is independently selected from hydrogen, —C(R) 2 OR, and C 1-6 alkyl, both R x are hydrogen, one R x is halogen and the other is hydrogen, or one R x is OH and the other is hydrogen, and R is C 1-6 alkyl.

15. A compound which is:

1-(6-(3,5-dimethyl-1H-1,2,4-triazol-1-yl)-2-methylpyrimidin-4-yl)-3-(1-methyl-1H-benzo[d]imidazol-2-yl)cyclobutanol,

2-(3-(6-(3,5-dimethyl-1H-1,2,4-triazol-1-yl)-2-methylpyrimidin-4-yl)-3-fluorocyclobutyl)-1-methyl-1H-benzo[d]imidazole,

2-((cis)-3-(6-(3,5-dimethyl-1H-1,2,4-triazol-1-yl)-2-methylpyrimidin-4-yl)cyclobutyl)-1-methyl-1H-benzo[d]imidazole,

2-((trans)-3-(6-(3,5-dimethyl-1H-1,2,4-triazol-1-yl)-2-methylpyrimidin-4-yl)cyclobutyl)-1-methyl-1H-benzo[d]imidazole,

or pharmaceutically acceptable salts thereof.

16. A pharmaceutical composition which comprises a pharmaceutically acceptable carrier and a compound of claim 1 or a pharmaceutically acceptable salt thereof.

17. A method for treating anxiety, in a mammalian patient in need thereof which comprises administering to the patient a therapeutically effective amount of a compound of claim 1 or a pharmaceutically acceptable salt thereof.