Potassium channel inhibitors

1. A compound of formula I,

or a pharmaceutically acceptable salt, or an optical isomer thereof, wherein:

R 1 , R 2 , and R 3 are independently selected from the group consisting of

1) hydrogen,

2) halogen,

3) NO 2 ,

4) CN,

5) CR 4= C(R 4 ) 2 ,

6) C≡CR 4 ,

7) (CR 5 2 ) n OR 4 ,

8) (CR 5 2 ) n N(R 4 )2,

9) (CR 5 2 ) n C(O)R 4 ,

10) (CR 5 2 ) n C(O)OR 4 ,

11) (CR 5 2 ) n R 4 ,

12) (CR 5 2 ) n S(O) m R 4 ,

13) (CR 5 2 ) n S(O) m N(R 4 )2,

14) OS(O) m R 4 ,

15) N(R 4 )C(O)R 4 ,

16) N(R 4 )S(O) m R 4 ,

17) (CR 5 2 ) n N(R 6 )R 4 ,

18) (CR 5 2 ) n N(R 4 )(CR 5 2 ) n C(O)N(R 4 )2,

19) (CR 5 2 ) n N(R 4 )(CR 5 2 ) n C(O)OR 4 ,

20) N(R 4 )(CR 5 2 ) n R 4 ,

21) N(R 4 )(CR 5 2 ) n N(R 4 )2,

22) (CR 5 2 ) n C(O)N(R 4 )2,

23) (CR 5 2 ) n C(O)NH(CR 5 2 ) n R 4 ,

24) (CR 5 2 ) n C(O)NHC(R 4 ) 2 (CR 5 2 ) n N(R 4 )2,

25) C(O)NH(CR 5 2 )(CR 5 3 ),

26) S(O) m R 5 , and

27) N(R 4 )(R 5 );

R 4 , in each instance in which it appears, is independently selected from the group consisting of

1) hydrogen,

2) C 1 -C 6 alkyl,

3) C 3 -C 10 cycloalkyl,

4) aryl,

5) CF 3 ,

6) C 2 -C 6 alkenyl, and

7) C 2 -C 6 alkynyl,

 or in the case where R 4 is attached to a nitrogen atom that is disubstituted with R 4 , each R 4 is independently selected from C 1 -C 6 alkyl, and the nitrogen atom together with each R 4 form a ring;

R 5 , in each instance in which it appears, is independently selected from the group consisting of

1) hydrogen,

2) C 1 -C 6 alkyl,

3) halogen,

4) aryl,

5) C 3 -C 10 cycloalkyl,

6) OR 4 , and

7) CH 2 OR 4 ;

m is independently selected from 0, 1 and 2; and

n is independently selected from 0, 1, 2, 3, 4, 5 and 6.

2. A compound of claim 1 , or a pharmaceutically acceptable salt thereof, or an optical isomer thereof, wherein R 1 is selected from the group consisting of hydrogen and halogen.

3. A compound of claim 2 , or a pharmaceutically acceptable salt thereof, or an optical isomer thereof, wherein R 1 is selected from the group consisting of hydrogen and F.

4. A compound of claim 1 , or a pharmaceutically acceptable salt thereof, or an optical isomer thereof, wherein R 2 is selected from the group consisting of hydrogen, halogen and CF 3 .

5. A compound of claim 4 , or a pharmaceutically acceptable salt thereof, or an optical isomer thereof, wherein R 2 is selected from the group consisting of hydrogen, Cl and CF 3 .

6. A compound of claim 1 , or a pharmaceutically acceptable salt thereof, or an optical isomer thereof, wherein R 3 is selected from the group consisting of hydrogen and halogen.

7. A compound of claim 6 , or a pharmaceutically acceptable salt thereof, or an optical isomer thereof, wherein R 3 is selected from the group consisting of hydrogen and Cl.

8. A compound of claim 1 , or a pharmaceutically acceptable salt thereof, selected from the group consisting of:

1-[2-(3,5-dichlorophenyl)pyridin-3-yl]-2,2-dipyridin-3-ylethanol,

2,2-dipyridin-3-yl-1-{2-[3-(trifluoromethyl)phenyl]pyridin-3-yl}ethanol,

1-[2-(2-chlorophenyl)pyridin-3-yl]-2,2-dipyridin-3-ylethanol,

1-[2-(3,5-dichlorophenyl)pyridin-3-yl]-2-(2-fluoropyridin-3-yl)-2-pyridin-3-ylethanol,

1-[2-(2,5-dichlorophenyl)pyridin-3-yl]-2,2-dipyridin-3-ylethanol, and

1-[2-(2,3-dichlorophenyl)pyridin-3-yl]-2,2-dipyridin-3-ylethanol.

9. A compound of claim 8 , or a pharmaceutically acceptable salt thereof, which is 1-[2-(3,5-dichlorophenyl)pyridin-3-yl]-2,2-dipyridin-3-ylethanol.

10. A compound of claim 9 , or a pharmaceutically acceptable salt thereof, which is (R)-1-[2-(3,5-dichlorophenyl)pyridin-3-yl]-2,2-dipyridin-3-ylethanol.

11. A pharmaceutical formulation comprising a pharmaceutically acceptable carrier and the compound claim 1 .