Compounds for nonsense suppression, and methods for their use

1. A compound of Formula 1-B or 1-D:

wherein:

R a is hydrogen or a C 1 -C 4 alkyl group;

n is 1, 2, or 3;

R 1 is a cyano group; or a carbonyl group which is substituted with a hydroxy, a C 1 -C 4 alkyl, or a C 1 -C 4 alkoxy group;

R is independently selected from a hydroxy group; a halogen; a C 1 -C 4 alkyl which is optionally substituted with one or more independently selected halogen or hydroxy groups; a C 1 -C 4 alkoxy which is optionally substituted with one or more independently selected halogen or phenyl groups; a C 4 -C 8 cycloalkyl which is optionally substituted with one or more independently selected C 1 -C 4 alkyl groups; an —R b group; a —O—R b group; a five to six-membered heterocycle which is optionally substituted with one or more independently selected C 1 -C 4 alkyl, oxo, or —R b groups; a nine to ten membered heterocycle having two ring structures; a carbonyl which is substituted with a C 1 -C 4 alkyl, or a C 1 -C 4 alkoxy group; a carbamoyl which is optionally substituted with one or two C 1 -C 4 alkyl groups; a nitro group; a thio which is optionally substituted with a hydroxy, a C 1 -C 4 alkyl, or —R b group; a sulfonyl which is optionally substituted with a hydroxy, a C 1 -C 4 alkyl, or —R b group; an amino which is optionally substituted with one or two independently selected C 1 -C 4 alkyl, sulfonyl, or carbonyl groups, wherein the aminosulfonyl group is optionally substituted with a hydroxy, a C 1 -C 4 alkyl, or an —R b group, and wherein the aminocarbonyl group is optionally substituted with a C 1 -C 4 alkyl, a C 1 -C 4 haloalkyl, a benzoxy, or an amino group which is optionally substituted with an —R b group; or two R groups together with the phenyl ring to which they are attached form a benzo[1,3]dioxole or a 2,3-dihydro-benzo[1,4]dioxinyl group; wherein

R b is a C 6 -C 8 aryl which is optionally substituted with one or more of the following: a hydroxy, a halogen, a C 1 -C 4 alkyl group, a C 1 -C 4 haloalkyl group, a C 1 -C 4 alkoxy group, or an amino group which is optionally substituted with one or more C 1 -C 4 alkyl groups;

wherein R 1 is in the meta or para position when said compound is a compound of Formula 1-B; or a pharmaceutically acceptable salt thereof.

2. A compound selected from the group consisting of:

and pharmaceutically acceptable salts thereof.

3. The compound of claim 1 , wherein

R a is hydrogen or a C 1 -C 4 alkyl group;

n is 1, or 2;

R 1 is a cyano group; or a carbonyl group which is substituted with a hydroxy;

R is independently selected from a hydroxy group; a halogen; a C 1 -C 4 alkyl which is optionally substituted with one or more independently selected halogen groups; a C 1 -C 4 alkoxy which is optionally substituted with one or more independently selected halogen groups; an —R b group; a five to six-membered heterocycle; an amino which is optionally substituted with one or two independently selected C 1 -C 4 alkyl groups; or two R groups together with the phenyl ring to which they are attached form a benzo[1,3]dioxole or a 2,3-dihydro-benzo[1,4]dioxinyl group; wherein —R b is a C 6 -C 8 aryl;

or a pharmaceutically acceptable salt thereof.

4. The compound of claim 3 , wherein R 1 is a carboxy group.

5. The compound of claim 3 , wherein R is independently selected from chloro, fluoro, bromo, methyl, isopropyl, tert-butyl, trifluoromethyl, methoxy, ethoxy, trifluoromethoxy, amino, dimethylamino, or two R groups together with the phenyl ring to which they are attached form a 2,3-dihydro-benzo[1,4]dioxinyl group.

6. The compound of claim 5 , wherein R is selected from methyl, fluoro, methoxy, ethoxy or trifluoromethyl.

7. The compound of claim 3 , wherein R a is hydrogen or methyl.

8. The compound of claim 6 , wherein R is located in one or more ortho position, one or more meta position, or a para position.