Substituted n′-hydroxycarbamimidoyl-1,2,5-oxadiazole compounds as indoleamine 2,3-dioxygenase (IDO) inhibitors

1. A compound of formula (I), or a pharmaceutically acceptable salt thereof:

wherein:

m is 0, 1, 2, or 3; n is 1, 2, or 3,

X is —S— or —NH—;

R is selected from the group consisting of:

(a) hydrogen,

(b) C 1-6 alkyl, optionally substituted with one to three substituents independently selected from the group consisting of (i) —OH, (ii) halogen, and (iii) —NH 2 ,

(c) C 3-6 cycloalkyl, optionally substituted with one to three substituents independently selected from the group consisting of (i) NH 2 , (ii) —NH—S(O) 2 —NH 2 and (iii) —NH—C(O)—C 1-6 alkyl, optionally substituted with —OH,

(d) C 4-6 cycloalkenyl, optionally substituted with an oxo,

(e) —(C═O)—NH—R a , wherein R a is selected from the group consisting of:

(i) hydrogen,

(ii) —C 1-6 alkyl, optionally substituted with one to three substituents independently selected from the group consisting of (1) halogen, (2) —OH and (3) —S(O) 2 —C 1-6 alkyl,

(iii) —C 1-6 alkoxy, and

(iv) —C 3-6 cycloalkyl,

(f) —NR x R y , wherein each of R x and R y is independently selected from the group consisting of:

(i) hydrogen,

(ii) —(C═O)—R a , wherein R a is selected from the group consisting of (1) hydrogen, and (2) —C 1-6 alkyl, optionally substituted with one to three substituents independently selected from halogen and —CN, (3) —NH 2 , (4) —NH—C 1-6 alkyl, optionally substituted with —OH, —O-methyl, or —CN, (5) —NH—C 3-6 cycloalkyl, and (6) heterocyclyl, optionally substituted with —OH,

(iii) —S(O) 2 —NH 2 ,

(iv) —S(O) 2 —CH 3 , and

(v) C 4-5 cycloalkenyl, optionally substituted with one to four substituents independently selected from the group consisting of (1) oxo, (2) —C 1-6 alkyl, and (3) —NH—C 1-6 alkyl,

(g) a 4-, 5- or 6-membered heterocyclyl, optionally substituted with one to four substituents independently selected from the group consisting of (i) halogen, (ii) C 1-6 alkyl, (iii) oxo, (iv) —C(O)—C 1-6 alkyl, optionally substituted with one to three groups independently selected from —OH and —O—C 1-6 alkyl, (v) —S(O) 2 —NH 2 and (vi) —S(O) 2 —NH—C 1-6 alkyl, optionally substituted with —OH,

(h) —S(O) 2 —C 1-6 alkyl, optionally substituted with one to three —OH groups,

(i) —O—S(O) 2 —NH 2 ;

(j)

(k) a 7-, 8-, 9- or 10-membered bi-cyclic heterocyclyl, optionally substituted with one to three substituents independently selected from the group consisting of (i) halogen, (ii) C 1-6 alkyl and (iii) oxo, and

(l) aryl, optionally substituted with one to three substituents independently selected from the group consisting of (i) halogen and (ii) —B(OH) 2 ;

each occurrence of R 1 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) —CN, and (d) C 1-6 alkyl, optionally substituted with 1 to 3 halogens;

each occurrence of R 2 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) —OH, (d) —NH 2 and (e) C 1-6 alkyl, optionally substituted with —OH;

each occurrence of R 3 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) C 1-6 alkyl, and (d) —O—C 1-6 alkyl; and

R 4 is selected from the group consisting of (a) hydrogen and (b) C 1-4 alkyl.

2. The compound of claim 1 , or a pharmaceutically acceptable salt thereof,

wherein: m is 0, 1, 2, or 3; n is 1, 2, or 3;

X is —S— or —NH—;

R is selected from the group consisting of:

(a) hydrogen,

(b) C 1-6 alkyl, optionally substituted with one to three substituents independently selected from the group consisting of (i) —OH, (ii) halogen, and (iii) —NH 2 ,

(c) C 3-6 cycloalkyl, optionally substituted with one to three substituents independently selected from the group consisting of (i) NH 2 , (ii) —NH—S(O) 2 —NH 2 and (iii) —NH—C(O)—C 1-6 alkyl, optionally substituted with —OH,

(d) C 4-6 cycloalkenyl, optionally substituted with an oxo,

(e) —(C═O)—NH—R a , wherein R a is selected from the group consisting of:

(i) hydrogen,

(ii) —C 1-6 alkyl, optionally substituted with one to three substituents independently selected from the group consisting of (1) halogen, (2) —OH and (3) —S(O) 2 —C 1-6 alkyl,

(iii) —C 1-6 alkoxy, and

(iv) —C 3-6 cycloalkyl,

(f) —NR x R y , wherein each of R x and R y is independently selected from the group consisting of:

(i) hydrogen,

(ii) —(C═O)—R a , wherein R a is selected from the group consisting of (1) hydrogen, and (2) —C 1-6 alkyl, optionally substituted with one to three substituents independently selected from halogen and —CN, (3) —NH 2 , (4) —NH—C 1-6 alkyl, optionally substituted with —OH, —O-methyl, or —CN, and (5) —NH—C 3-6 cycloalkyl,

(iii) —S(O) 2 —NH 2 ,

(iv) —S(O) 2 —CH 3 , and

(v) C 4-5 cycloalkenyl, optionally substituted with one to four substituents independently selected from the group consisting of (1) oxo, (2) —C 1-6 alkyl, and (3) —NH—C 1-6 alkyl, and

(g) a 4-, 5- or 6-membered heterocyclyl, optionally substituted with one to four substituents independently selected from the group consisting of (i) halogen, (ii) C 1-6 alkyl, (iii) oxo and (iv) —C(O)—C 1-6 alkyl, optionally substituted with one to three —OH groups;

each occurrence of R 1 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) —CN, and (d) C 1-6 alkyl, optionally substituted with 1 to 3 halogens;

each occurrence of R 2 is independently selected from the group consisting of (a) hydrogen, (b) halogen, and (c) —OH;

each occurrence of R 3 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) C 1-6 alkyl, and (d) —O—C 1-6 alkyl; and

R 4 is selected from the group consisting of (a) hydrogen and (b) C 1-4 alkyl.

3. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein m is 1 or 2; and n is 1 or 2.

4. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein R is selected from the group consisting of:

(a) C 1-4 alkyl, optionally substituted with one to two —OH groups,

(b) C 3-4 cycloalkyl,

(c) —(C═O)—NH—R a , wherein R a is selected from the group consisting of:

(i) hydrogen,

(ii) —C 1-6 alkyl,

(iii) —C 1-6 alkoxy, and

(iv) —C 3-6 cycloalkyl,

(d) —NR x R y , wherein each of R x and R y is independently selected from the group consisting of:

(i) hydrogen,

(ii) —(C═O)—C 1-6 alkyl,

(iii) —S(O) 2 —NH 2 , and

(iv) cyclobutenyl, optionally substituted with one to three substituents independently selected from the group consisting of (1) oxo, (2) —C 1-4 alkyl, and (3) —NH—C 1-4 alkyl, and

(e) a 5- or 6-membered heterocyclyl, optionally substituted with one to four substituents independently selected from the group consisting of (i) C 1-6 alkyl, and (ii) oxo.

5. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein R is a 5- or 6-membered heterocyclyl selected from the group consisting of pyridinyl, pyrimidinyl, piperidinyl, triazolyl, and thiazolyl;

wherein the 5- or 6-membered heterocyclyl is optionally substituted with one to four substituents independently selected from the group consisting of (i) C 1-6 alkyl, and (ii) oxo.

6. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein each occurrence of R 1 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) —CN, and (d) C 1-4 alkyl, optionally substituted with 1 to 3 halogens.

7. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein each occurrence of R 2 is independently selected from the group consisting of (a) hydrogen, and (b) —OH.

8. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein each occurrence of R 3 is independently selected from the group consisting of (a) hydrogen, (b) C 1-4 alkyl, and (c) —O—C 1-4 alkyl.

9. The compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein:

R is selected from the group consisting of:

(a) C 1-4 alkyl, optionally substituted with one to two —OH groups,

(b) C 3-4 cycloalkyl,

(c) —(C═O)—NH—R a , wherein R a is selected from the group consisting of (i) hydrogen, (ii) —C 1-6 alkyl, and (iii) —C 1-6 alkoxy,

(d) —NR x R y , wherein each of R x and R y is independently selected from the group consisting of (i) hydrogen, (ii) —(C═O)—C 1-6 alkyl, and (iii) —S(O) 2 —NH 2 , and

(e) 5- or 6-membered heterocyclyl, optionally substituted with one to four substituents independently selected from the group consisting of (i) C 1-6 alkyl and (ii) oxo

each occurrence of R 1 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) —CN, and (d) C 1-4 alkyl, optionally substituted with 1 to 3 halogens;

each occurrence of R 2 is independently selected from the group consisting of (a) hydrogen, and (b) —OH;

each occurrence of R 3 is independently selected from the group consisting of (a) hydrogen, (b) C 1-4 alkyl, and (c) —O—C 1-4 alkyl; and

R 4 is selected from the group consisting of (a) hydrogen, and (b) C 1-4 alkyl.

10. The compound of claim 1 of formula (Ia), or a pharmaceutically acceptable salt thereof:

wherein:

m is 1, 2, or 3; n is 1 or 2;

X is —S— or —NH—;

R b is selected from the group consisting of:

(a) C 1-6 alkyl, optionally substituted with one to two —OH groups,

(b) C 3-6 cycloalkyl,

(c) C 1-6 alkoxy, and

(d) —NR x N y , wherein each of R x and R y is independently selected from the group consisting of (i) hydrogen, (ii) —C 1-6 alkyl, (iii) —C 3-6 cycloalkyl and (iv) —(C═O)—C 1-6 alkyl;

each occurrence of R 1 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) —CN, and (d) C 1-4 alkyl, optionally substituted with 1 to 3 halogens;

each occurrence of R 2 is independently selected from the group consisting of (a) hydrogen, and (b) —OH; and

each occurrence of R 3 is independently selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, and (c) —O—C 1-6 alkyl.

11. The compound of claim 10 , or a pharmaceutically acceptable salt thereof, wherein R b is selected from the group consisting of methyl, ethyl, propyl, iso-propyl, methoxy, ethoxy, propoxy and cyclopropyl.

12. The compound of claim 10 , or a pharmaceutically acceptable salt thereof, wherein:

each occurrence of R 1 is independently selected from the group consisting of (a) hydrogen, (b) halogen, (c) —CN, and (d) —CF 3 .

13. The compound of claim 10 , or a pharmaceutically acceptable salt thereof, wherein:

each occurrence of R 2 is hydrogen.

14. The compound of claim 10 , or a pharmaceutically acceptable salt thereof, wherein:

each occurrence of R 3 is independently selected from the group consisting of (a) hydrogen, (b) methyl, (c) ethyl, (d) —O-methyl, and (c) —O-ethyl.

15. The compound of claim 1 of formula (Ib), or a pharmaceutically acceptable salt thereof:

wherein

m is 1, 2, or 3; n is 1 or 2;

X is —S— or —NH—,

R b is selected from the group consisting of:

(a) C 1-6 alkyl, optionally substituted with one to two —OH groups, and

(b) C 3-6 cycloalkyl;

each occurrence of R 1 is independently selected from the group consisting of (a) hydrogen, (b) halogen, and (c) —CN;

each occurrence of R 2 is independently selected from the group consisting of (a) hydrogen, and (b) —OH; and

each occurrence of R 3 is independently selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, and (c) —O—C 1-6 alkyl.

16. The compound of claim 15 , or a pharmaceutically acceptable salt thereof, wherein:

each occurrence of R 1 is independently selected from the group consisting of (a) hydrogen, (b) halogen, and (c) —CN.

17. The compound of claim 16 , or a pharmaceutically acceptable salt thereof, wherein:

each occurrence of R 2 is hydrogen and each occurrence of R 3 is independently selected from the group consisting of (a) hydrogen, (b) methyl, and (c) ethyl.

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

4-Amino-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(R)-4-Amino-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(S)-4-Amino-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(S)-4-amino-N-(bicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(R)-4-amino-N-(bicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-Amino-N′-hydroxy-N-(7-methylbicyclo[4.2.0]octa-1,3,5-trien-7-yl)-1,2,5-oxadiazole-3-carboximidamide,

(S)-4-amino-N′-hydroxy-N-(7-methylbicyclo[4.2.0]octa-1,3,5-trien-7-yl)-1,2,5-oxadiazole-3-carboximidamide,

(R)-4-amino-N′-hydroxy-N-(7-methylbicyclo[4.2.0]octa-1,3,5-trien-7-yl)-1,2,5-oxadiazole-3-carboximidamide,

(S)-4-Amino-N-(2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(R)-4-Amino-N-(2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-Amino-N-(8-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-Amino-N-(8,8-difluorobicyclo[4.2.0]octa-1 (6),2,4-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-Amino-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N′-hydroxy-N-(1,2,3,4-tetrahydronaphthalen-1-yl)-1,2,5-oxadiazole-3-carboximidamide, trans-4-amino-N-((1R,2R)-2-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N-(5-chloro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N′-hydroxy-N-(6-methyl-2,3-dihydro-1H-inden-1-yl)-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N-(4-chloro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N′-hydroxy-N-(4-methyl-2,3-dihydro-1H-inden-1-yl)-1,2,5-oxadiazole-3-carboximidamideidamide,

4-amino-N-(4-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N-(5-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N-(6-bromo-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

cis-4-amino-N′-hydroxy-N-(3-methyl-2,3-dihydro-1H-inden-1-yl)-1,2,5-oxadiazole-3-carboximidamide,

trans-4-amino-N′-hydroxy-N-(3-methyl-2,3-dihydro-1H-inden-1-yl)-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N-(4,6-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N-(4-fluoro-7-methylbicyclo[4.2.0]octa-1 (6),2,4-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-amino-N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(4-amino-N-(3,3-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(sulfamoylamino)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

(S)—N-(2-((4-(N-(2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide,

(R)—N-(2-((4-(N-(2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide,

(S)—N-(2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide,

(R)—N-(2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide,

(S)- or R—N-(2-((4-(N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide,

(S)—N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-4-(((6-oxo-1,6-dihydropyridin-2-yl)methyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

(R)—N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-4-(((6-oxo-1,6-dihydropyridin-2-yl)methyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

(S)—N-(2-((4-(N-(2-chlorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide,

(R)—N-(2-((4-(N-(2-chlorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide,

(R)- or (S)—N-Ethyl-2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide,

(S)—N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(sulfamoylamino)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

(R)—N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(sulfamoylamino)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

(S)- or (R)—N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-ureidoethyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-(2-hydroxyethyl)acetamide,

(S,S)-4-((2,3-dihydroxypropyl)thio)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(S,R)-4-((2,3-dihydroxypropyl)thio)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(R,S)-4-((2,3-dihydroxypropyl)thio)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(R,R)-4-((2,3-dihydroxypropyl)thio)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

(S)—N-ethyl-2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)acetamide,

(R)—N-ethyl-2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)acetamide,

(S)-2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-(2-hydroxyethyl)acetamide,

(R)-2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-(2-hydroxyethyl)acetamide,

(S)-2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-(2-hydroxyethyl)acetamide,

(R)-2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-(2-hydroxyethyl)acetamide,

N-(Bicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(sulfamoylamino)ethyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

N-(2-((4-(N-(6-bromo-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide (racemic),

N-(2-((4-(N-(6-bromo-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide (chiral, peak 1),

N-(2-((4-(N-(6-bromo-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide (chiral, peak 2),

N-(2-((4-(N-(6-chloro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide (chiral, peak 1),

2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide (chiral peak 1),

2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide (chiral, peak 2),

2-((4-(N-(2-bromobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide,

2-((4-(N-(6-bromo-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide,

2-((4-(N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-(2-hydroxyethyl)acetamide,

2-((4-(N-(bicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide,

2-((4-(N-(6-bromo-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide,

2-((4-(N-(2-chlorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide,

(N-(2-((4-(N-(6,7-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide (chiral, peak 1),

(N-(2-((4-(N-(6,7-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide (chiral, peak 2),

(N-(2-((4-(N-(4,6-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide (peak 1),

(N-(2-((4-(N-(4,6-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)ethyl)acetamide (peak 2),

(2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (chiral, peak 1),

(2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (chiral, peak 2),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-(((4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

2-((4-(N-(bicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide,

N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-ureidoethyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

2-((4-(N′-hydroxy-N-(6-(trifluoromethyl)-2,3-dihydro-1H-inden-1-yl)carbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide,

N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-(((4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-(((4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

N-cyclopropyl-2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide,

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-(((6-oxo-1,6-dihydropyridin-2-yl)methyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-isopropylacetamide,

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-(((4-methyl-6-oxo-1,6-dihydropyridin-2-yl)methyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

2-((4-(N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide,

2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide,

(2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide,

N-ethyl-2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (peak 1),

N-ethyl-2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (peak 2),

2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-isopropylacetamide (peak 1),

2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-isopropylacetamide (peak 2),

2-((4-(N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-isopropylacetamide,

N-cyclopropyl-2-((4-(N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (peak 1),

N-cyclopropyl-2-((4-(N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (peak 2),

N-cyclopropyl-2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (peak 1),

N-cyclopropyl-2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (peak 2),

2-((4-(N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide,

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide (peak 1),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-methylacetamide (peak 2),

((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (peak 1),

((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)acetamide (peak 2),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-cyclopropylacetamide (peak 1),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-cyclopropylacetamide (peak 2),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-ethylacetamide (peak 1),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-ethylacetamide (peak 2),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-isopropylacetamide (peak 1),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-isopropylacetamide (peak 2),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-(2-hydroxyethyl)acetamide (peak 1),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-(2-hydroxyethyl)acetamide (peak 2),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(methylsulfonamido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(methylsulfonamido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-(2-hydroxyethyl)acetamide (peak 1),

2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-N-(2-hydroxyethyl)acetamide (peak 2),

N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(methylsulfonamido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(methylsulfonamido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(methylsulfonamido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(3-(2-methoxyethyl)ureido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(3-(2-methoxyethyl)ureido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

4-((2-(3-cyclopropylureido)ethyl)thio)-N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide (peak 1),

4-((2-(3-cyclopropylureido)ethyl)thio)-N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide (peak 2),

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(3-(2-methoxyethyl)ureido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(3-(2-methoxyethyl)ureido)ethyl)thio)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-ureidoethyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

4-((2,3-dihydroxypropyl)thio)-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(sulfamoylamino)ethyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(sulfamoylamino)ethyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

N-ethyl-2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)acetamide,

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-(((4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-(((4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

(Z)-2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-methylacetamide,

2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-isopropylacetamide (peak 1),

2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-isopropylacetamide (peak 2),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-(((6-oxo-1,6-dihydropyridin-2-yl)methyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-(((6-oxo-1,6-dihydropyridin-2-yl)methyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

N-cyclopropyl-2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)acetamide (peak 1),

N-cyclopropyl-2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)acetamide (peak 2),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-methylacetamide (peak 1),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-methylacetamide (peak 2),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-(((4-methyl-6-oxo-1,6-dihydropyridin-2-yl)methyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)acetamide (peak 1),

2-((4-(N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)acetamide (peak 2),

4-(((R)-2,3-dihydroxypropyl)amino)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide (peak 1),

4-(((R)-2,3-dihydroxypropyl)amino)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide (peak 2),

4-(((S)-2,3-dihydroxypropyl)amino)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide (peak 1),

4-(((S)-2,3-dihydroxypropyl)amino)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide (peak 2),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(methylsulfonamido)ethyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-(methylsulfonamido)ethyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-ethylacetamide,

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((((R)-1-methyl-2-oxoimidazolidin-4-yl)methyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

2-((4-(N′-hydroxy-N-(6-(trifluoromethyl)-2,3-dihydro-1H-inden-1-yl)carbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-methylacetamide,

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-(2-hydroxyethyl)acetamide,

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-ureidoethyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-4-((2-ureidoethyl)amino)-1,2,5-oxadiazole-3-carboximidamide (peak 2),

2-((4-(N-(6-cyano-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-isopropylacetamide,

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-(((4-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-isopropylacetamide (peak 1),

2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-isopropylacetamide (peak 2),

4-((2,3-dihydroxy-2-methylpropyl)amino)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-(methylsulfonamido)ethyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

4-(((R)-2,3-dihydroxy-3-methylbutyl)amino)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-(((S)-2,3-dihydroxy-3-methylbutyl)amino)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-(((R)-2,3-dihydroxypropyl)amino)-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-(((S)-2-amino-3-hydroxypropyl)amino)-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

4-((2,3-dihydroxy-2-methylpropyl)amino)-N-(2-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-ureidoethyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

N-(2-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-ureidoethyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

N—((S)-4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-(((S)-2-hydroxy-3-(sulfamoylamino)propyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

N—((S)-4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-(((R)-2-hydroxy-3-(sulfamoylamino)propyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

4-[(2,3-dihydroxy-3-methylbutyl)sulfanyl]-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide (peak 1),

4-[(2,3-dihydroxy-3-methylbutyl)sulfanyl]-N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide (peak 2),

N˜2˜-{4-[N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-(2-hydroxy-2-methylpropyl)glycinamide,

N˜2˜-{4-[N-(6-fluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-(1-hydroxy-2-methylpropan-2-yl)glycinamide,

2-[(4-{N-[(1 S)-6-fluoro-2,3-dihydro-1H-inden-1-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]-N-(2-hydroxy-2-methylpropyl)acetamide,

N˜2˜-{4-[N-(5,6-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-(2-hydroxyethyl)glycinamide,

2-((4-(N-(6,7-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)-N-(2-hydroxyethyl)acetamide,

N˜2˜-{4-[N-(6,7-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-[(2R)-2,3-dihydroxypropyl]glycinamide,

N˜2˜-{4-[N-(5,6-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-[(2R)-2,3-dihydroxypropyl]glycinamide,

N˜2˜-(4-{N-[7 S)-4-chlorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)-N-(2-hydroxyethyl)glycinamide,

N-(2,3-dihydroxypropyl)-N˜2˜-(4-{N-[(1 S)-6-fluoro-2,3-dihydro-1H-inden-1-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)glycinamide,

N˜2˜-(4-{N-[(1 S)-6-fluoro-2,3-dihydro-1H-inden-1-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)-N-(2-hydroxypropyl)glycinamide,

2-[(4-{N-[(1 S)-6-fluoro-2,3-dihydro-1H-inden-1-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]-N-(2-hydroxypropyl)acetamide,

2-[(4-{N-[(1 S)-6-fluoro-2,3-dihydro-1H-inden-1-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]-N-(1-hydroxy-2-methylpropan-2-yl)acetamide,

4-({[(3R)-1,1-dioxo-1lambda˜6˜,2,5-thiadiazolidin-3-yl]methyl}sulfanyl)-N-[(1 S)-6-fluoro-2,3-dihydro-1H-inden-1-yl]-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N˜2˜-(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)glycinamide,

N-{2-[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)amino]ethyl}acetamide,

N˜2˜-{4-[N-(6,7-difluoro-2,3-dihydro-1H-inden-1-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-[2-(methyl sulfonyl)ethyl]glycinamide,

N˜2˜-(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)-N-(2-hydroxyethyl)-D-alaninamide,

N˜2˜-(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)-N-(2-hydroxyethyl)-L-alaninamide,

N-(2,3-dihydroxypropyl)-2-[(4-{N-[(1 S)-6-fluoro-2,3-dihydro-1H-inden-1-yl]-N-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]acetamide,

N˜2˜-{4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-(2-hydroxy-2-methylpropyl)glycinamide,

N-(2,3-dihydroxypropyl)-2-({4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}sulfanyl)acetamide,

2-({4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}sulfanyl)-N-(2-hydroxy-2-methylpropyl)acetamide,

N˜2˜-{4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-(1-hydroxy-2-methylpropan-2-yl)glycinamide,

2-({4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}sulfanyl)-N-(1-hydroxy-2-methylpropan-2-yl)acetamide,

N˜2˜-{4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-(2-hydroxypropyl)glycinamide,

2-({4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}sulfanyl)-N-(2-hydroxypropyl)acetamide,

N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-4-[(3-oxocyclopent-1-en-1-yl)amino]-1,2,5-oxadiazole-3-carboximidamide,

4-[(2,4-dioxo-1,3-diazaspiro[4.5]decan-8-yl)amino]-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N˜2˜-{4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-(2-hydroxypropyl)glycinamide,

2-cyano-N-{2-[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]ethyl}acetamide,

N-{2-[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]ethyl}-2-hydroxyacetamide,

N˜2˜-(4-{N-[(7S)-4-bromobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)-N-(2-hydroxyethyl)glycinamide,

2-cyano-N-[2-({4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}amino)ethyl]acetamide,

4-{[(1-aminocyclopropyl)methyl]amino}-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-[2-({4-[N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}amino)ethyl]-2-hydroxyacetamide,

N-(2,3-dihydroxypropyl)-N˜2˜-{4-[N-(4-fluorobicyclo [4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}glycinamide,

4-(carbamoylamino)-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-4-({[1-(sulfamoylamino)cyclopropyl]methyl}amino)-1,2,5-oxadiazole-3-carboximidamide,

N˜2˜-{4-[N-(3-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}-N-(2-hydroxyethyl)glycinamide,

N-(4-fluorobicyclo [4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-4-{[1-(hydroxyacetyl)azetidin-3-yl]sulfanyl}-1,2,5-oxadiazole-3-carboximidamide,

4-[(azetidin-3-yl)sulfanyl]-N-(4-fluorobicyclo [4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-{2-[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)amino]propyl}acetamide,

N-[(7 S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-[(2-hydroxyethyl)amino]-1,2,5-oxadiazole-3-carboximidamide,

N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-{[(2 S)-1-hydroxypropan-2-yl]amino}-1,2,5-oxadiazole-3-carboximidamide,

N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-4-{[(2R)-3-hydroxy-2-(sulfamoylamino)propyl]sulfanyl}-1,2,5-oxadiazole-3-carboximidamide,

2-({4-[N-(4-chloro-3-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}sulfanyl)-N-(2-hydroxyethyl)acetamide,

2-({4-[N-(3,4-difluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxycarbamimidoyl]-1,2,5-oxadiazol-3-yl}sulfanyl)-N-(2-hydroxyethyl)acetamide,

(2R)—N-{2-[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]ethyl}-2,3-dihydroxypropanamide,

(2S)—N-{2-[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]ethyl}-2,3-dihydroxypropanamide,

4-({[(3R)-1,1-dioxo-1lambda˜6˜,2,5-thiadiazolidin-3-yl]methyl}sulfanyl)-N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-(4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl)-N′-hydroxy-4-{[2-(methyl sulfonyl)ethyl]amino}-1,2,5-oxadiazole-3-carboximidamide,

4-{[1-(2,3-dihydroxypropanoyl)azetidin-3-yl]sulfanyl}-N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N—((S)-4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-((2-hydroxy-3-(methylsulfonamido)propyl)thio)-1,2,5-oxadiazole-3-carboximidamide,

N—((S)-4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxy-4-(((1 s,3R)-3-(sulfamoylamino)cyclobutyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

(S)—N-(4-fluorobicyclo [4.2.0]octa-1 (6),2,4-trien-7-yl)-N′-hydroxy-4-((2-((2-hydroxyethyl)sulfonyl)ethyl)amino)-1,2,5-oxadiazole-3-carboximidamide,

N-(3-((4-(N—((S)-4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)thio)-2-hydroxypropyl)-2-hydroxyacetamide,

(2S)-1-[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)amino]propan-2-yl sulfamate,

S-(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)-L-cysteinamide,

N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-({1-[(2-hydroxyethyl)sulfamoyl]azetidin-3-yl}sulfanyl)-1,2,5-oxadiazole-3-carboximidamide,

N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-[(1-sulfamoylazetidin-3-yl)sulfanyl]-1,2,5-oxadiazole-3-carboximidamide,

4-[(2-azaspiro[3.3]heptan-6-yl)amino]-N-[(7 S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-[(7 S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-({[(2R)-morpholin-2-yl]methyl}amino)-1,2,5-oxadiazole-3-carboximidamide,

4-[(trans-3-aminocyclobutyl)amino]-N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide,

N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-{[1-(3-hydroxypropanoyl)azetidin-3-yl]sulfanyl}-1,2,5-oxadiazole-3-carboximidamide,

N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-{[1-(methoxyacetyl)azetidin-3-yl]sulfanyl}-1,2,5-oxadiazole-3-carboximidamide,

N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-[(2-hydroxyethyl)sulfanyl]-1,2,5-oxadiazole-3-carboximidamide,

N-[(7 S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-{[2-hydroxy-4-(methylsulfonyl)butyl]amino}-1,2,5-oxadiazole-3-carboximidamide (peak 1),

N-[(7 S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-{[2-hydroxy-4-(methylsulfonyl)butyl]amino}-1,2,5-oxadiazole-3-carboximidamide (peak 2),

N-{2-[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)sulfanyl]ethyl}-3-hydroxypropanamide,

(3-{[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)amino]methyl}phenyl)boronic acid,

(4-{[(4-{N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxycarbamimidoyl}-1,2,5-oxadiazol-3-yl)amino]methyl}phenyl)boronic acid,

N-[(7S)-4-fluorobicyclo[4.2.0]octa-1,3,5-trien-7-yl]-N′-hydroxy-4-({3-[hydroxy(dimethyl)silyl]propyl}amino)-1,2,5-oxadiazole-3-carboximidamide, and

(S,Z)-N-(2-((4-(N-(4-fluorobicyclo[4.2.0]octa-1(6),2,4-trien-7-yl)-N′-hydroxycarbamimidoyl)-1,2,5-oxadiazol-3-yl)amino)ethyl)-1-hydroxy-3,4-dihydro-1H-benzo[c][1,2]oxaborinine-8-carboxamide.

19. A composition which comprises an inert carrier and a compound of claim 1 or a pharmaceutically acceptable salt thereof.

20. A method for treating an IDO-associated disease or disorder in a mammalian subject which comprises administering to the subject an effective amount of a compound of claim 1 or a pharmaceutically acceptable salt thereof,

wherein the disease or disorder is selected from a cancer of the colon, pancreas, breast, prostate, lung, brain, ovary, cervix, testes, renal, head and neck, lymphoma, leukemia, and melanoma.