Imidazole derivatives as IDO inhibitors

1. A compound according to the formula,

a tautomer thereof, or a pharmaceutically acceptable salt thereof, wherein

n is 1, 2, or 3;

p is 0 or 1;

each R 1 is independently hydrogen or methyl;

R 12 is hydrogen or halogen;

R 15 is hydrogen or hydroxy; and

R 2 is C 3 -C 8 cycloalkyl, C 3 -C 8 cycloalkenyl, heterocyclyl, aryl, or heteroaryl, each optionally substituted with one R 20 group and optionally substituted with one R 21 group, wherein C 3 -C 8 cycloalkyl is cyclopentyl, cyclopentenyl, cyclohexyl, cyclohexenyl, cycloheptyl, cyclooctyl, bicyclo[3.1.1]heptane, bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, bicyclo[3.2.2]nonane, bicyclo[3.3.1]nonane or bicyclo[4.2.1]nonane;

R 20 is halogen, —C(O)R, —C(O)OR, —N(H)R, —N(H)C(O)C(H)(R 22 )R, —N(H)S(O) 2 R, —N(H)C(O)R, —N(H)C(O)OR, —N(H)C(O)N(H)R, heteroaryl, heterocyclyl, wherein R 22 is N(R 23 ) 2 ) or —N(H)C(O)R 23 , wherein R 23 is hydrogen or C 1 -C 6 alkyl;

R 21 is halogen or trifluoromethyl; and

R is hydrogen, C 1 -C 6 alkyl, aryl, heteroaryl, C 3 -C 8 cycloalkyl, heterocyclyl, aryl(C 1 -C 6 )alkyl, heteroaryl(C 1 -C 6 )alkyl, heterocyclyl(C 1 -C 6 )alkyl, wherein the heterocyclyl, aryl, heteroaryl, cycloalkyl, heterocyclyl, heterocyclylalkyl, arylalkyl, and heteroarylalkyl are each optionally substituted with one group that is halogen, cyano, nitro, —OR 10 , —N(R 10 ) 2 , —C(O)OR 10 , —C(O)N(R 10 ) 2 , —C(O)R 10 , or C 1 -C 6 alkyl, wherein each R 10 is independently hydrogen, C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, heterocyclyl, aryl, or heteroaryl,

provided that the compound is not

4-(2-(2-bromophenethoxy)phenyl)-1H-imidazole;

3-(2-chlorophenethoxy)-2-(1H-imidazol-5-yl)phenol;

5-(2-(4-chlorobenzyloxy)phenyl)-1H-imidazole;

4-(2-(2-chlorophenethoxy)phenyl)-1H-imidazole;

4-(2-(2-cyclohexylethoxy)phenyl)-1H-imidazole;

4-(2-(2-cyclopropylethoxy)phenyl)-1H-imidazole;

5-(2-(2-cyclopentylethoxy)phenyl)-1H-imidazole;

4-(2-phenethoxyphenyl)-1H-imidazole;

5-(2-(3-chlorobenzyloxy)phenyl)-1H-imidazole;

4-(2-(3-chlorophenethoxy)phenyl)-1H-imidazole;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)acetamide;

N-(3-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)acetamide;

5-(2-(3-phenylpropoxy)phenyl)-1H-imidazole;

4-(2-(benzyloxy)phenyl)-1H-imidazole;

4-(3-bromo-2-(4-chlorobenzyloxy)phenyl)-1H-imidazole;

4-(2-(4-chlorophenethoxy)phenyl)-1H-imidazole;

3-(4-chlorobenzyloxy)-2-(1H-imidazol-5-yl)phenol;

4-(2-(2-chlorobenzyloxy)phenyl)-1H-imidazole;

3-((2-(1H-imidazol-4-yl)phenoxy)methyl)piperidine;

1-(4-((2-(1H-imidazol-4-yl)phenoxy)methyl)piperidin-1-yl)ethanone;

1-(3-((2-(1H-imidazol-4-yl)phenoxy)methyl)piperidin-1-yl)ethanone;

4-(2-(2-bromophenethoxy)phenyl)-1H-imidazole;

tert-butyl 4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)piperidine-1-carboxylate;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)piperidin-1-yl)ethanone;

4-((2-(1H-imidazol-4-yl)phenoxy)methyl)piperidine;

N-(2-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)acetamide;

4-((2-(1H-imidazol-5-yl)phenoxy)methyl)-7-methoxy-2H-chromen-2-one;

3-(2-(2-(1H-imidazol-5-yl)phenoxy)ethyl)-1H-indole;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(4-(pyrrolidin-1-yl)phenyl)ethanone;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(benzofuran-2-yl)ethanone;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(thiazol-2-yl)ethanone;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(benzofuran-5-yl)ethanone;

2-(3-(2-(1H-imidazol-5-yl)phenoxy)propyl)isoindoline-1,3-dione;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(4-(diethylamino)phenyl)ethanone;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(thiophen-3-yl)ethanone;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(thiophen-2-yl)ethanone;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(benzofuran-3-yl)ethanone;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(pyridin-2-yl)ethanone;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(pyridin-4-yl)ethanone;

1-(2-(2-(1H-imidazol-5-yl)phenoxy)ethyl)-1H-pyrazole;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(benzo[b]thiophen-5-yl)ethanone;

2-(2-(2-(1H-imidazol-5-yl)phenoxy)ethyl)isoindoline-1,3-dione;

2-(2-(1H-imidazol-5-yl)phenoxy)-1-(3-phenylisoxazol-5-yl)ethanone;

5-(2-(2-(2,3-dihydrobenzofuran-5-yl)ethoxy)phenyl)-1H-imidazole;

5-(2-(1-phenylpropan-2-yloxy)phenyl)-1H-imidazole;

3-(2-(2-(1H-imidazol-5-yl)phenoxy)acetyl)-2H-chromen-2-one;

2-(2-(1H-imidazol-5-yl)phenoxy)-2,3-dihydro-1H-inden-1-one;

5-(2-((2,3-dihydrobenzo[b][1,4]dioxin-2-yl)methoxy)phenyl)-1H-imidazole;

5-(2-(2-(1H-pyrrol-1-yl)ethoxy)phenyl)-1H-imidazole;

2-((2-(1H-imidazol-5-yl)phenoxy)methyl)-1H-benzo[d]imidazole;

6-(2-(2-(1H-imidazol-5-yl)phenoxy)acetyl)-2H-benzo[b][1,4]oxazin-3(4H)-one;

6-(2-(2-(1H-imidazol-5-yl)phenoxy)acetyl)benzo[d]oxazol-2(3H)-one;

2-((2-(1H-imidazol-5-yl)phenoxy)methyl)pyridine;

5-((2-(1H-imidazol-5-yl)phenoxy)methyl)-2-chloropyridine;

4-((2-(1H-imidazol-5-yl)phenoxy)methyl)pyridine;

2-((2-(1H-imidazol-5-yl)phenoxy)methyl)quinazolin-4(3H)-one;

2-((2-(1H-imidazol-5-yl)phenoxy)methyl)quinoline;

3-((2-(1H-imidazol-5-yl)phenoxy)methyl)quinoxalin-2(1H)-one;

3-((2-(1H-imidazol-5-yl)phenoxy)methyl)benzo[d]thiazol-2(3H)-one;

5-(2-(naphthalen-2-ylmethoxy)phenyl)-1H-imidazole; and

5-(2-(2-(naphthalen-1-yl)ethoxy)phenyl)-1H-imidazole.

2. The compound of claim 1 according to the formula,

or a pharmaceutically acceptable salt thereof.

3. The compound of claim 1 according to the formula,

or a pharmaceutically acceptable salt thereof.

4. The compound of claim 1 according to the formula,

or a pharmaceutically acceptable salt thereof, wherein R 21 is hydrogen, halogen, or trifluoromethyl; and X is —C(H)═ or —N═.

5. The compound of claim 1 according to the formula,

a tautomer thereof, or a pharmaceutically acceptable salt thereof, wherein

X is —C(H)═ or —N═;

L is a bond, —CH 2 , —O—, or —N(H)—;

R 25 is hydrogen, C 1 -C 6 alkyl, aryl, heteroaryl, C 3 -C 8 cycloalkyl, or heterocyclyl, wherein the aryl, heteroaryl, cycloalkyl, and heterocyclyl, groups are each optionally substituted with one group that is halogen, cyano, nitro, —OR 11 , —N(R 11 ) 2 , —C(O)OR 11 , —C(O)N(R 11 ) 2 , —C(O)R 11 , or C 1 -C 6 alkyl, wherein each R 11 is independently hydrogen, C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, heterocyclyl, aryl, or heteroaryl; and

R 21 is hydrogen, halogen, or trifluoromethyl;

provided that R 25 can be hydrogen only when L is —CH 2 —; and the compound is not

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)acetamide.

6. The compound according to claim 1 that is

4-(2-(3,4-dichlorobenzyloxy)phenyl)-1H-imidazole;

2-(2-(1H-imidazol-4-yl)phenoxy)-1-(benzo[b]thiophen-6-yl)ethanone;

4-(2-(4-fluorobenzyloxy)phenyl)-1H-imidazole;

4-(2-(benzo[d][1,3]dioxol-5-ylmethoxy)phenyl)-1H-imidazole;

4-(2-(benzofuran-5-ylmethoxy)phenyl)-1H-imidazole;

4-(2-(2-(benzofuran-3-yl)propoxy)phenyl)-1H-imidazole;

3-(2-cyclohexylethoxy)-2-(1H-imidazol-5-yl)phenol;

4-(2-(2-(trifluoromethyl)phenethoxy)phenyl)-1H-imidazole;

4-(2-(1-(2-chlorophenyl)propan-2-yloxy)phenyl)-1H-imidazole;

4-(2-(1-cyclohexylpropan-2-yloxy)phenyl)-1H-imidazole;

tert-butyl 4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenylcarbamate;

4-(2-(2-cyclohexylpropoxy)phenyl)-1H-imidazole hydrochloride;

4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)aniline;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)pivalamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-phenylacetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-3,3-dimethylbutanamide;

ethyl 4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenylcarbamate;

5-(2-(2-fluorophenethoxy)phenyl)-1H-imidazole;

benzyl 4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenylcarbamate;

3-(4-chlorophenethoxy)-2-(1H-imidazol-5-yl)phenol;

neopentyl 4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)piperidine-1-carboxylate;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)thiophene-2-carboxamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-1-phenylmethanesulfonamide;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-3-phenylurea;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(pyrazin-2-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(thiophen-2-yl)acetamide;

or a pharmaceutically acceptable salt thereof.

7. The compound according to claim 1 that is

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)acetamide;

3-(3-chlorophenethoxy)-2-(1H-imidazol-5-yl)phenol;

(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)piperidin-1-yl)(thiophen-2-yl)methanone;

4-chloro-3-(2-cyclohexylethoxy)-2-(1H-imidazol-5-yl)phenol;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)piperidin-1-yl)-2-(thiophen-2-yl)ethanone;

5-(3-chloro-2-(2-cyclohexylethoxy)phenyl)-1H-imidazole;

3-(2-(cyclohex-3-en-1-yl)ethoxy)-2-(1H-imidazol-5-yl)phenol;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)piperidin-1-yl)-2-phenylethanone;

4-(2-(2-(cyclohex-3-en-1-yl)ethoxy)phenyl)-1H-imidazole;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-3-(2-nitrophenyl)urea;

4-(2-(2-(thiophen-2-yl)ethoxy)phenyl)-1H-imidazole;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(tetrahydrofuran-2-yl)acetamide;

4-(2-(4-(thiophen-3-yl)phenethoxy)phenyl)-1H-imidazole;

4-(2-(2-(thiophen-3-yl)ethoxy)phenyl)-1H-imidazole;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-oxo-1,2-dihydropyridine-3-carboxamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(tetrahydro-2H-pyran-4-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-morpholinoacetamide;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-3-(2-aminocyclohexyl)urea;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(1H-imidazol-1-yl)acetamide;

6-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-N-phenylbenzo[d]oxazol-2-amine;

1-(5-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)pyridin-2-yl)-3-phenylurea;

4-(2-(4-(pyrrolidin-1-yl)phenethoxy)phenyl)-1H-imidazole;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(thiazol-4-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(pyrimidin-2-yl)acetamide;

N-(5-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)pyridin-2-yl)-2-phenylacetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(pyrimidin-5-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(3-nitrophenyl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(2-nitrophenyl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(3-aminophenyl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(4-nitrophenyl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(2-aminophenyl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(4-aminophenyl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2-(2-aminothiazol-4-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-2-(tetrahydro-2H-pyran-4-yl)acetamide;

methyl 3-((4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)carbamoyl)benzoate;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-3-(tetrahydro-2H-pyran-4-yl)urea;

4-((4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)carbamoyl)benzoic acid;

methyl 4-((4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)carbamoyl)benzoate;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxamide;

3-((4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)carbamoyl)benzoic acid;

2-((4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)phenyl)carbamoyl)benzoic acid;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-fluorophenyl)-2-(tetrahydro-2H-pyran-4-yl)acetamide;

4-(2-(2-chlorophenethoxy)-3-fluorophenyl)-1H-imidazole;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-2-chlorophenyl)-2-(tetrahydro-2H-pyran-4-yl)acetamide;

N-(3-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-4-chlorophenyl)-2-(tetrahydro-2H-pyran-4-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-(trifluoromethyl)phenyl)-2-(tetrahydro-2H-pyran-4-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-2-amino-2-(tetrahydro-2H-pyran-4-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-2-acetamido-2-(tetrahydro-2H-pyran-4-yl)acetamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)piperidine-2-carboxamide;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-2-aminonicotinamide;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-3-(3-((tetrahydrofuran-3-yl)oxy)phenyl)urea;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-3-phenylurea;

2-(2-(1H-imidazol-4-yl)phenoxy)-1-cyclohexylethanone;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-3-((1R,2R)-2-aminocyclohexyl)urea;

N-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-2-(pyrimidin-5-yl)acetamide;

1-(4-(2-(2-(1H-imidazol-4-yl)phenoxy)ethyl)-3-chlorophenyl)-3-((1R,2S)-2-aminocyclohexyl)urea;

or a pharmaceutically acceptable salt thereof.

8. A compound according to the formula,

a tautomer thereof, or a pharmaceutically acceptable salt thereof, wherein

R 14 is halogen;

R 15 is hydrogen or hydroxy, and

R 4 is hydrogen or —C(O)R 5 , wherein

R 5 is (i) C 1 -C 6 alkyl; or

(ii) —N(R 2 )(R 3 ), wherein

R 2 is C 1 -C 6 alkyl, aryl, —C 1 -C 6 alkyl-OC(O)R 6 , or —C(H)(R 22 )C(O)OR 7 , wherein

R 22 is hydrogen, C 1 -C 6 alkyl, aryl, heteroaryl, arylC 1 -C 6 alkyl, or heteroarylC 1 -C 6 alkyl, wherein the alkyl, arylalkyl, and heteroarylalkyl groups are optionally substituted with one group that is halo,

cyano, —OR 23 , —SR 23 , —N(R 23 ) 2 , —C(O)OR 23 , —C(O)N(R 23 ) 2 , —N(R 23 )C(═NR 23 )N(R 23 ) 2 , or C 1 -C 6 alkyl, wherein each R 23 is hydrogen or C 1 -C 6 alkyl; and

R 6 is C 1 -C 6 alkyl;

R 7 is hydrogen or C 1 -C 6 alkyl;

R 3 is hydrogen or C 1 -C 6 alkyl;

or R 2 and R 3 taken together with the nitrogen to which they are attached form a heterocyclyl group, wherein the heterocyclyl group is optionally substituted with one or two groups that are each independently oxo or C 1 -C 6 alkyl;

provided that the compound is not

4-chloro-2-(1H-imidazol-5-yl)phenol; and

4-bromo-2-(1H-imidazol-5-yl)phenol.

9. The compound of claim 8 , wherein R 4 is hydrogen.

10. The compound of claim 8 , according to the formula,

a tautomer thereof, or a pharmaceutically acceptable salt thereof, wherein

R 14 is halogen;

R 15 is hydrogen or hydroxy, and

R 5 is (i) C 1 -C 6 alkyl; or

(ii) —N(R 2 )(R 3 ), wherein

R 2 is C 1 -C 6 alkyl, aryl, —C 1 -C 6 alkyl-OC(O)R 6 , or —C(H)(R 22 )C(O)OR 7 , wherein

R 22 is hydrogen, C 1 -C 6 alkyl, aryl, heteroaryl, arylC 1 -C 6 alkyl, or heteroarylC 1 -C 6 alkyl, wherein the alkyl, arylalkyl, and heteroarylalkyl groups are optionally substituted with one group that is halo, cyano, —OR 23 , —SR 23 , —N(R 23 ) 2 , —C(O)OR 23 , —C(O)N(R 23 ) 2 , —N(R 23 )C(═NR 23 )N(R 23 ) 2 , or C 1 -C 6 alkyl, wherein each R 23 is hydrogen or C 1 -C 6 alkyl; and

R 6 is C 1 -C 6 alkyl;

R 7 is hydrogen or C 1 -C 6 alkyl; and

R 3 is hydrogen or C 1 -C 6 alkyl;

or R 2 and R 3 taken together with the nitrogen to which they are attached form a heterocyclyl group, wherein the heterocyclyl group is optionally substituted with one or two groups that are each independently oxo or C 1 -C 6 alkyl.

11. The compound of claim 8 that is

4-bromo-2-(1H-imidazol-4-yl)phenyl pivalate;

4-chloro-2-(1H-imidazol-4-yl)phenyl dimethylcarbamate;

4-chloro-2-(1H-imidazol-4-yl)phenyl diisopropylcarbamate;

4-chloro-2-(1H-imidazol-4-yl)phenyl pyrrolidine-1-carboxylate;

4-chloro-2-(1H-imidazol-4-yl)phenyl methyl(phenyl)carbamate;

4-chloro-2-(1H-imidazol-4-yl)phenyl 4-methylpiperazine-1-carboxylate;

4-chloro-2-(1H-imidazol-4-yl)phenyl 2-oxoimidazolidine-1-carboxylate;

or a pharmaceutically acceptable salt thereof.

12. The compound of claim 8 that is

2-(((4-chloro-2-(1H-imidazol-4-yl)phenoxy)carbonyl)(methyl)amino)ethyl acetate;

(R)-methyl 2-(((4-chloro-2-(1H-imidazol-4-yl)phenoxy)carbonyl)amino)-3-(1-methyl-1H-indol-3-yl)propanoate;

or a pharmaceutically acceptable salt thereof.

13. A compound according to the formula,

a tautomer thereof, or a pharmaceutically acceptable salt thereof, wherein

R 13 is hydrogen, halogen, or —SH; and

R 12 is R 20 ;

R 14 and R 15 are each independently hydrogen or R 20 , wherein

each R 20 is independently halogen, cyano, —OR, —SR, —NR 2 , —C(O)OR, —C(O)NR 2 , —N(R)S(O) 2 R, —C(O)R 2 , —S(O)R, —S(O) 2 R, —S(O)OR, —S(O) 2 OR, —S(O)NR 2 , —S(O) 2 NR 2 , —OC(O)R, —OC(O)OR, —OC(O)NR 2 , —N(R)C(O)R, —N(R)C(O)OR, —N(R)C(O)NR 2 , —N(R)S(O)R, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 haloalkyl, C 3 -C 8 cycloalkyl, heterocyclyl, aryl, heteroaryl, C 3 -C 8 cycloalkyl(C 1 -C 6 )alkyl, heterocyclyl(C 1 -C 6 )alkyl, aryl(C 1 -C 6 )alkyl, or heteroaryl(C 1 -C 6 )alkyl;

each R is independently hydrogen or R 2 , wherein

R 2 is C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 haloalkyl, C 3 -C 8 cycloalkyl, heterocyclyl, aryl, heteroaryl, C 3 -C 8 cycloalkyl(C 1 -C 6 )alkyl, heterocyclyl(C 1 -C 6 )alkyl, aryl(C 1 -C 6 )alkyl, or heteroaryl(C 1 -C 6 )alkyl, wherein the alkyl, cycloalkyl, heterocyclyl, aryl, heteroaryl, cycloalkylalkyl, heterocyclylalkyl, arylalkyl, and heteroarylalkyl are each optionally substituted with 1, 2, 3, or 4 groups which are each independently halogen, cyano, nitro, —OR 10 , —SR 10 , —N(R 10 ) 2 , —C(O)OR 10 , —C(O)N(R 10 ) 2 , —C(O)R 10 , —S(O)R 10 , —S(O) 2 R 10 , —S(O)OR 10 , —S(O) 2 OR 10 , —S(O)N(R 10 ) 2 , —S(O) 2 N(R 10 ) 2 , —OC(O)R 10 , —OC(O)OR 10 , —OC(O)N(R 10 ) 2 , —N(R 10 )C(O)R 10 , —N(R 10 )C(O)OR 10 , —N(R 10 )C(O)N(R 10 ) 2 , —N(R 10 )S(O)R 10 , —N(R 10 )S(O) 2 R 10 , C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 haloalkyl, C 3 -C 8 cycloalkyl, heterocyclyl, aryl, or heteroaryl, wherein each R 10 is independently hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 haloalkyl, C 3 -C 8 cycloalkyl, heterocyclyl, aryl, heteroaryl, C 3 -C 8 cycloalkyl(C 1 -C 6 )alkyl, heterocyclyl(C 1 -C 6 )alkyl, aryl(C 1 -C 6 )alkyl, or heteroaryl(C 1 -C 6 )alkyl.

14. A pharmaceutical composition comprising a pharmaceutically acceptable excipient, diluent, or carrier, and a compound according to any one of claims 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , and 13 .

15. A method for treating indoleamine 2,3-dioxygenase (IDO) mediated immunosuppression in a subject in need thereof, comprising administering an effective indoleamine 2,3-dioxygenase inhibiting amount of (i) a compound or (ii) a pharmaceutical composition comprising a pharmaceutically acceptable excipient, diluent, or carrier, and the compound, wherein the compound is according to any one of claims 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , and 13 .