Papain-like protease (PLpro) inhibitors

1 . A compound of Formula (I):

or a pharmaceutically acceptable salt thereof, wherein:

X 1 is N or CR 2 ;

X 2 is N or CH;

X 3 is N or CR 9 provided that X 2 and X 3 cannot be both N;

X 4 is CH or N, provided that X 1 and X 4 are not N at the same time and X 4 can only be N when R 6 is —CH 3 , R 7 is H, R 8 is H, X 3 is CR 9 and R 9 is —(CR g R h )—O—(CR g R h )R 12 ;

R 2 is selected from the group consisting of H, halogen, hydroxy, cyano, C 1 -C 6 alkyl, C 1 -C 6 hydroxyalkyl, C 1 -C 6 alkoxy-C 1 -C 6 alkyl, C 1 -C 6 aminoalkyl, C 1 -C 6 fluoroalkyl and C 1 -C 6 alkoxy;

R 3 is selected from the group consisting of H, halogen, hydroxy, cyano, C 1 -C 6 alkyl, C 1 -C 6 hydroxyalkyl, C 1 -C 6 alkoxy-C 1 -C 6 alkyl, C 1 -C 6 aminoalkyl, C 1 -C 6 fluoroalkyl and C 1 -C 6 alkoxy;

R 1 is selected from the group consisting of -L 1 -L 2 -L 3 -Cyc 1 , C 1 -C 6 alkyl, C 1 -C 6 aminoalkyl, C 1 -C 6 cyanoalkyl, C 1 -C 6 alkyl-C(═O)—N(R a )R b , —N(R a )R b , —N(R a )(C 1 -C 6 alkoxy-C 1 -C 6 alkyl), —N(R a )(C 1 -C 6 alkyl-C(═O)—C 1 -C 6 alkyl), —N(R a )(C(═O)—C 1 -C 6 alkyl), —N(R a )(C 1 -C 6 alkyl-C(═O)—N(R c )R d ), —N(R a )(C 1 -C 6 alkyl-SO 2 —N(R c )R d ), —O—C 1 -C 6 hydroxyalkyl, —O—(C 1 -C 6 alkoxy-C 1 -C 6 alkyl);

L 1 , L 2 and L 3 are each either absent or independently selected from the group consisting of O, NR a , C(═O) and C 1 -C 3 alkylene;

Cyc 1 is selected from the group consisting of C 6 -C 10 aryl, 5-10 membered heteroaryl, C 3 -C 8 cycloalkyl, 3-10 membered heterocycloalkyl, C 3 -C 8 cycloalkenyl and 3-8 membered heterocycloalkenyl, each optionally substituted by one, two or three R 10 ;

R a , R b , R c and R d are each independently selected at each occurrence from the group consisting of H and C 1 -C 4 alkyl;

R 4 and R 5 are each independently selected from the group consisting of H and C 1 -C 4 alkyl, C 1 -C 4 aminoalkyl and C 1 -C 4 alkoxy-C 1 -C 4 alkyl, or alternatively R 4 and R 5 together with the carbon atom to which they are attached form a C 3 -C 6 cycloalkyl optionally substituted by one R 10 or a 4-8 membered heterocycloalkyl optionally substituted by one R 10 ;

R 6 is selected from the group consisting of H, halogen, cyano, nitro, C 1 -C 6 alkyl, —C 1 -C 6 fluoroalkyl, C 1 -C 6 aminoalkyl, C 1 -C 6 alkoxy-C 1 -C 6 alkyl, —OR 12 , —SR 12 , C 1 -C 3 alkyl-C(═O)—N(R e )—N(R f )—C(═O)—CH═CH—C(═O)—O—C 1 -C 6 alkyl, C 1 -C 3 alkyl-C(═O)—N(R e )—N(R f )—C(═O)—CH═CH—O—C 1 -C 6 alkyl, C 1 -C 3 alkyl-C(═O)—N(R e )—N(R f )—C(═O)-oxiran-C(═O)—O—C 1 -C 6 alkyl, C 1 -C 3 alkyl-C(═O)—N(R e )—N(R f )—C(═O)-oxiran-C(═O)—OH and C 1 -C 3 alkyl-C(═O)—N(R e )—N(R)—C(═O)—CH═CH—C(═O)—N(R 11 )R 12 ;

R e and R f are each independently selected at each occurrence from the group consisting of H and C 1 -C 4 alkyl;

R 7 and R 8 are each independently selected from the group consisting of H, halogen, hydroxy, C 1 -C 6 alkyl, C 1 -C 6 alkoxy-C 1 -C 6 alkyl, 4-10 membered heterocycloalkyl, —C 1 -C 6 alkyl-NR 14 R 15 , —NHR 16 , —N(R 13 )—C(═O)—R 16 , and —C(═O)—NR 14 R 15 , wherein any said 4-10 membered heterocycloalkyl is optionally substituted with one, two or three R 10 ;

R 9 is selected from the group consisting of H, halogen, hydroxy, cyano, C 1 -C 6 alkyl, C 1 -C 6 alkoxy-C 1 -C 6 alkyl, C 1 -C 6 alkyl-C(═O)—OH, —C(═O)—O—C 1 -C 6 alkyl, —C(═O)—N(R 11 )R 12 , —C(═O)—N(R 11 )—C 1 -C 3 alkyl-R 12 , —C(═O)—N(R 11 )—(CR g R h )—R 12 , —(CR g R h )—CH(OH)—(CR g R h )—R 12 , —(CR g R h )—CH(OCH 3 )—(CR g R h )—R 12 , —(CR g R h )—N(R 11 )—(CR g R h )—R 12 , —(CR g R h )—O—(CR g R h )—R 12 , —(CR g R h )—S—(CR g R h )—R 12 , —(CR g R h )—S(═O)—(CR g R h )—R 12 , —(CR g R h )—SO 2 —(CR g R h )—R 12 , —SO 2 —N(R 11 )—(CR g R h )—R 12 , —C 1 -C 3 alkyl-C(═O)—N(R 11 )R 12 , —(CR g R h )—C(═O)—N(R 11 )R 12 , —(CR g R h )—SO 2 —N(R 11 )R 12 , —C 1 -C 3 alkyl-C(═O)—N(R 11 )—C 1 -C 3 alkyl-R 12 , —N(R 11 )R 12 , —N(R 11 )—C 1 -C 3 alkyl-R 12 , —O—C 1 -C 3 alkyl-R 12 , —N(R 11 )—C(═O)—N(R 13 )—R 12 , —C 1 -C 3 alkyl-N(R 11 )R 12 , —C 1 -C 3 alkyl-N(R 11 )—C 1 -C 3 alkyl-R 12 , —C 1 -C 3 alkyl-N(R 11 )—C(═O)—R 12 , —(CR g R h )—N(R 11 )—(CR g R h )—R 12 , —(CR g R h )—N(R 11 )—C(═O)—R 12 , —C 1 -C 3 alkyl-N(R 11 )—C(═O)—C 1 -C 3 alkyl-R 12 and —(CR g R h )—OR 12 ;

Each of R g and R h is independently selected from the group consisting of H, cyano, halogen, hydroxy, C 1 -C 6 alkyl, C 1 -C 6 fluoroalkyl, C 1 -C 6 aminoalkyl, C 1 -C 6 alkoxy, C 1 -C 6 hydroxyalkyl, —C 1 -C 6 alkoxy-C 1 -C 6 alkyl, or alternatively, R g and R h together with the carbon atom to which they are attached form a C 1 -C 6 cycloalkyl or a 4-8 membered Heterocycloalkyl, each optionally substituted by one R 10 ;

with the proviso that at least one of R 7 , R 8 and R 9 is H and that R 6 , R 7 , R 8 and R 9 are not all H at the same time;

Each R 10 is independently selected at each occurrence from the group consisting of cyano, nitro, oxo, 1-(1-cyanocyclopropyl)methyl, halogen, C 1 -C 6 alkyl, C 1 -C 6 fluoroalkyl, C 1 -C 6 aminoalkyl, —C 1 -C 6 alkyl-R 12 , C 1 -C 6 alkoxy, C 1 -C 6 alkoxy-C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 6 cycloalkyl, 3-8 membered heterocycloalkyl, —COOH, —C(═O)—O—C 1 -C 6 alkyl, —C(═O)—N(R 11 )R 12 , —N(R 11 )R 12 , —C 1 -C 3 alkyl-N(R 11 )R 12 , —C 1 -C 3 alkyl-C(═O)—N(R 11 )R 12 , —(C(CH 3 ) 2 )—C(═O)—N(R 11 )R 12 , —N(R 11 )C(═O)R 12 , —C 1 -C 3 alkyl-N(R 11 )C(═O)R 12 , —S(O)R 12 , —S(O) 2 R 12 , —C 1 -C 3 alkyl-S(O) 2 R 12 , —S(O) 2 N(R 11 )R 12 , —N(R 13 )S(O) 2 N(R 11 )R 12 , —N(R 13 )S(O) 2 R 12 , —OR 12 , —C 1 -C 3 alkyl-OR 12 and —SR 12 ;

Each R 11 is independently selected from H, —SO 2 CH 3 , —C(═O)CH 3 and C 1 -C 6 alkyl;

Each R 12 is independently selected from H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy-C 1 -C 6 alkyl, C 1 -C 6 aminoalkyl, di(C 1 -C 3 alkyl)amino-C 1 -C 6 alkyl, C 1 -C 6 fluoroalkyl, C 3 -C 8 cycloalkyl, 4-8 membered heterocycloalkyl, phenyl and 5-6 membered heteroaryl, wherein said C 3 -C 8 cycloalkyl, 4-8 membered heterocycloalkyl, phenyl and 5-6 membered heteroaryl are each optionally substituted by one or two R 17 ;

Or alternatively R 11 and R 12 together form a 4-8 membered heterocycloalkyl;

Each R 13 is independently selected from H and C 1 -C 6 alkyl;

Each R 14 and R 15 is independently selected from the group consisting of H, C 1 -C 6 alkyl, C 1 -C 6 fluoroalkyl, C 1 -C 6 aminoalkyl, —SO 2 —C 1 -C 6 alkyl and C 1 -C 6 alkoxy-C 1 -C 6 alkyl;

Each R 16 is a 3-8 membered heterocycloalkyl optionally substituted with one, two or three R 10 ; and

Each R 17 is independently selected from the group consisting of H, halogen, hydroxy, cyano, C 1 -C 6 alkyl, C 1 -C 6 hydroxyalkyl, C 1 -C 6 alkoxy-C 1 -C 6 alkyl, C 1 -C 6 aminoalkyl, C 1 -C 6 fluoroalkyl, C 1 -C 6 alkoxy and C 3 -C 6 cycloalkyl.

2 . A compound of claim 1 having the formula (Ib1):

or a pharmaceutically acceptable salt thereof, wherein X 1 is CH or N and X 4 is CH or X 1 is CH and X 4 is N.

3 . A compound of claim 2 which is of formula:

or a pharmaceutically acceptable salt thereof.

4 . A compound of claim 1 having Formula (Ib2):

or a pharmaceutically acceptable salt thereof, wherein X 1 is CH or N.

5 . A compound of claim 1 having Formula (Ib3):

or a pharmaceutically acceptable salt thereof, wherein R 9 is —(CR g R h )—O—(CR g R h )R 12 .

6 . A compound of any one of claims 2 to 4 , or a pharmaceutically acceptable salt thereof, wherein:

R 9 is selected from the group consisting of C 1 -C 6 alkyl-C(═O)—OH, —C(═O)—N(R 11 )R 12 , —C(═O)—N(R 11 )—C 1 -C 3 alkyl-R 12 , —C(═O)—N(R 11 )—(CR g R h )—R 12 —(CR g R h )—CH(OH)—(CR g R h )—R 12 , —(CR g R h )—CH(OCH 3 )—(CR g R h )—R 12 , —(CR g R h )—N(R 11 )—(CR g R h )—R 12 , —(CR g R h )—O—(CR g R h )—R 12 , (CR g R h )—S—(CR g R h )—R 12 , —(CR g R h )—S(═O)—(CR g R h )—R 12 , —C 1 -C 3 alkyl-C(═O)—N(R 11 )R 12 , —(CR g R h )—C(═O)—N(R 11 )R 12 , —C 1 -C 3 alkyl-N(R 11 )R 12 , —C 1 -C 3 alkyl-N(R 11 )—C 1 -C 3 alkyl-R 12 , —(CR g R h )—N(R 11 )—C(═O)—R 12 and —(CR g R h )—OR 12 ;

Each of R g and R h is independently selected from the group consisting of H, C 1 -C 6 alkyl, C 1 -C 6 fluoroalkyl, —C 1 -C 6 alkoxy-C 1 -C 6 alkyl, or alternatively, R g and R h together with the carbon atom to which they are attached form a C 3 -C 6 cycloalkyl;

Each R 11 is independently selected from H, —SO 2 CH 3 , —C(═O)CH 3 and C 1 -C 6 alkyl;

Each R 12 is independently selected from C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, 4-8 membered heterocycloalkyl and 5-6 membered heteroaryl, wherein said C 3 -C 8 cycloalkyl, 4-8 membered heterocycloalkyl and 5-9 membered heteroaryl are each optionally substituted by one or two R 17 ; and

Each R 17 is independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 hydroxyalkyl, C 1 -C 6 fluoroalkyl and C 3 -C 6 cycloalkyl.

7 . A compound of claim 6 , or a pharmaceutically acceptable salt thereof, wherein R 9 is —CH 2 —C(═O)OH, —CH 2 NH 2 , —CH 2 —C(═O)—NH(CH 3 ), —CH 2 —C(═O)—N(CH 3 ) 2 , —CH 2 —NH—CH 2 -heteroaryl or —CH 2 —NH—C(═O)-heteroaryl, —C(═O)—NH—CH 2 -heteroaryl, —C(═O)—NH—CH(CH 3 )-heteroaryl, —C(═O)—NH—C(CH 3 ) 2 -heteroaryl, —CH 2 —C(═O)—NH-heteroaryl, —C(═O)—NH—C(cyclopropyl)-heteroaryl, —C(CH 3 ) 2 —NH—CH 2 -heteroaryl, —CH 2 —N(CH 3 )—CH 2 -heteroaryl, —CH 2 —N(CH 3 )—C(═O)-heteroaryl, —CH(CH 3 —)—NH—C(═O)-heteroaryl, —C(cyclopropyl)-NH—C(═O)-heteroaryl, —C(═O)—N(CH 3 )—CH 2 -heteroaryl, —CH 2 —N(SO 2 CH 3 )—CH 2 -heteroaryl, —CH 2 —N(C(O)CH 3 )—CH 2 -heteroaryl, —C(CH 3 ) 2 —NH—C(═O)-heteroaryl, —CH 2 —O—CH 2 -heteroaryl, —CH 2 —S—CH 2 -heteroaryl, —CH 2 —S(O)—CH 2 -heteroaryl, —CH(CH 3 )—O—CH 2 -heteroaryl, —CH(OH)—C(═O)—NH-heteroaryl, —CH(CF 3 )—NH—CH 2 -heteroaryl, —CH(CH 2 OCH 3 )—O—CH 2 -heteroaryl, —CH(CH 2 OCH 3 )—NH—CH 2 -heteroaryl, —CH 2 —CH(OH)— CH 2 -heteroaryl, —CH 2 —CH(OCH 3 )—CH 2 -heteroaryl, —CH 2 —O-heteroaryl, wherein said heteroaryl is a pyridinyl or a 5-membered heteroaryl comprising 1 N atom and additionally comprising 1, 2, or 3 heteroatoms selected from N, O and S, said heteroaryl being optionally substituted by one or two R 17 groups selected from methyl, ethyl, isopropyl, hydroxymethyl, chloro, difluoromethyl, trifluoromethyl, cyclopropyl, cyclobutyl or cyclopentyl.

8 . A compound of any one of claims 2 to 7 , or a pharmaceutically acceptable salt thereof, wherein R 9 is —CH 2 —O—CH 2 -heteroaryl and said heteroaryl is a pyridinyl or a 5-membered heteroaryl comprising 1 N atom and additionally comprising 1, 2, or 3 heteroatoms selected from N, O and S.

9 . A compound of claim 4 , or a pharmaceutically acceptable salt thereof, wherein X 1 is N; R 9 is —CH 2 —O—CH 2 -heteroaryl wherein said heteroaryl is pyridinyl, thiazolyl or oxazolyl; and R 1 is a pyrazolyl substituted by —C(═O)—N(CH 3 ) 2 or —CH 2 —C(═O)—N(CH 3 ) 2 .

10 . A compound of claim 5 , or a pharmaceutically acceptable salt thereof, wherein R 9 is —CH 2 —O—CH 2 -heteroaryl wherein said heteroaryl is pyridinyl, thiazolyl or oxazolyl; and R 1 is a pyrazolyl substituted by —C(═O)—N(CH 3 ) 2 or —CH 2 —C(═O)—N(CH 3 ) 2 .

11 . A compound of any one of claims 9 and 10 , or a pharmaceutically acceptable salt thereof, wherein R 9 is selected from:

12 . A compound of any one of claims 9 to 11 , or a pharmaceutically acceptable salt thereof, wherein R 1 is:

13 . A compound of claim 1 which is selected from the group consisting of:

4-((((1H-imidazol-2-yl)methyl)amino)methyl)-2-methyl-N-(1-(3-(1-methyl-1H-pyrazol-4-yl)naphthalen-1-yl)ethyl)benzamide;

2-methyl-N-(1-(3-(1-methyl-1H-pyrazol-4-yl)naphthalen-1-yl)ethyl)-4-(((thiazol-4-ylmethyl)amino)methyl)benzamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-(((thiazol-4-ylmethyl)amino)methyl)benzamide;

N-(3-methyl-4-((1-(3-(1-methyl-1H-pyrazol-4-yl)naphthalen-1-yl)ethyl)carbamoyl)benzyl)thiazole-4-carboxamide N-(3-methyl-4-((1-(3-(1-methyl-1H-pyrazol-4-yl)naphthalen-1-yl)ethyl)carbamoyl)benzyl)-1H-imidazole-2-carboxamide;

(R)-2-(3-methyl-4-((1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)carbamoyl)phenyl)acetic acid;

(R)-2-methyl-N1-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-N4-(thiazol-4-ylmethyl)terephthalamide;

2-methyl-N1-((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-N4-(1-(thiazol-4-yl)ethyl)terephthalamide;

(R)-2-methyl-N1-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-N4-((5-methylthiazol-4-yl)methyl)terephthalamide;

(R)-2-methyl-N1-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-N4-((2-methylthiazol-4-yl)methyl)terephthalamide;

(R)-N4-(1-(1H-imidazol-2-yl)cyclopropyl)-2-methyl-N1-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)terephthalamide;

(R)—N4,2-dimethyl-N 1 -(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-N 4 -(thiazol-4-ylmethyl)terephthalamide;

(R)-N4-(2-(1H-imidazol-2-yl)propan-2-yl)-2-methyl-N1-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)terephthalamide;

(R)-N4-((1H-imidazol-2-yl)methyl)-2-methyl-N1-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)terephthalamide;

N4-(1-(1H-imidazol-2-yl)ethyl)-2-methyl-N1-((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)terephthalamide;

2-methyl-N 4 -((1-methyl-1H-imidazol-2-yl)methyl)-N 1 -(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl) terephthalamide;

2-methyl-N 1 -(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-N 4 -(thiazol-4-ylmethyl)terephthalamide;

(R)-2-methyl-N4-((1-methyl-1H-imidazol-2-yl)methyl)-N 1 -(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)terephthalamide;

2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-4-(((thiazol-4-ylmethyl)amino)methyl)benzamide;

(R)—N-(1-(3-methyl-4-((1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl) carbamoyl)phenyl)cyclopropyl)thiazole-4-carboxamide;

(R)—N-(1-(3-methyl-4-((1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)carbamoyl)phenyl)cyclopropyl)-1H-imidazole-2-carboxamide;

(R)—N-(2-(3-methyl-4-((1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl) carbamoyl)phenyl)propan-2-yl)thiazole-4-carboxamide;

(R)—N-(2-(3-methyl-4-((1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl) carbamoyl)phenyl)propan-2-yl)-1H-imidazole-2-carboxamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-(2-((thiazol-4-ylmethyl)amino)propan-2-yl)benzamide;

N-(1-(3-methyl-4-(((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)carbamoyl)phenyl)ethyl)thiazole-4-carboxamide;

N-(1-(3-methyl-4-(((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)carbamoyl)phenyl)ethyl)-1H-imidazole-2-carboxamide;

(R)-2-methyl-4-((methyl(thiazol-4-ylmethyl)amino)methyl)-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

(R)-2-methyl-4-((((1-methyl-1H-imidazol-5-yl)methyl)amino)methyl)-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-(2-oxo-2-(thiazol-4-ylamino)ethyl)benzamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-(2-oxo-2-(thiazol-5-ylamino)ethyl)benzamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-(2-oxo-2-(thiazol-2-ylamino)ethyl)benzamide;

(R)-4-(2-((1H-imidazol-2-yl)amino)-2-oxoethyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-(2-(methylamino)-2-oxoethyl)benzamide;

(R)-4-(2-(dimethylamino)-2-oxoethyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-((N-(thiazol-4-ylmethyl)acetamido)methyl)benzamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-((N-(thiazol-4-ylmethyl)methylsulfonamido)methyl)benzamide;

(R)—N-methyl-N-(3-methyl-4-((1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)carbamoyl)benzyl)thiazole-4-carboxamide;

(R)—N-methyl-N-(3-methyl-4-((1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)carbamoyl)benzyl)-1H-imidazole-2-carboxamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-((thiazol-4-ylmethoxy)methyl)benzamide;

(R)-2-methyl-4-((((1-methyl-1H-imidazol-2-yl)methyl)thio)methyl)-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

2-methyl-4-((((1-methyl-1H-imidazol-2-yl)methyl)sulfinyl)methyl)-N—((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

4-methyl-N—((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-6-(1-(thiazol-4-ylmethoxy)ethyl)nicotinamide;

(R)-2-methyl-4-(((1-methyl-1H-imidazol-2-yl)methoxy)methyl)-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

(R)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-(2-((5-methylthiazol-4-yl)amino)-2-oxoethyl)benzamide;

4-(1-hydroxy-2-oxo-2-(thiazol-4-ylamino)ethyl)-2-methyl-N—((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

4-methyl-6-(1-((1-methyl-1H-imidazol-2-yl)methoxy)ethyl)-N—((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)nicotinamide;

2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-4-((thiazol-4-ylmethoxy)methyl)benzamide;

2-methyl-N—((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-4-(2,2,2-trifluoro-1-((thiazol-4-ylmethyl)amino)ethyl)benzamide;

2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-4-(2-oxo-2-(thiazol-4-ylamino)ethyl)benzamide;

(R)-2-methyl-N1-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-N4-(1-(thiazol-4-yl)cyclopropyl)terephthalamide;

(R)-2-methyl-N1-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)-N4-((5-methyloxazol-4-yl)methyl)terephthalamide;

rel-(R)-4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)benzamide, ENT-1;

rel-(R)-4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)benzamide, ENT-2;

4-(2-methoxy-3-(pyridin-2-yl)propyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)benzamide;

4-(2-hydroxy-3-(pyridin-2-yl)propyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)benzamide;

2-methyl-N-(1-(2-(1-(2-(methylsulfonyl)ethyl)-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-4-((thiazol-4-ylmethoxy)methyl)benzamide;

N-(2-(dimethylamino)ethyl)-N-methyl-5-(4-(1-(2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamido)cyclopropyl)quinolin-2-yl)-1H-pyrazole-3-carboxamide;

4-(((5-(hydroxymethyl)thiazol-4-yl)methoxy)methyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)benzamide;

N-(1-(2-(1-(2-(dimethylamino)-2-oxoethyl)-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamide;

N-(1-(2-(1-(2-amino-2-oxoethyl)-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamide;

4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(2-methyl-7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)benzamide;

N-(1-(2-(2-hydroxypropan-2-yl)-7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)-2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamide;

N-(1-(2-hydroxy-7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)-2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamide;

N-(1-(2-(1-(2-(dimethylamino)-2-oxoethyl)-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-2-methyl-4-((pyridin-2-ylmethoxy)methyl)benzamide;

4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methyl-N—((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide;

4-((R*)-2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methyl-N—((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide, ENT-1;

4-((R*)-2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methyl-N—((R)-1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)ethyl)benzamide, ENT-2;

rel-(R)-4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)benzamide, ENT-1;

rel-(R)-4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)benzamide, ENT-2;

rel-(R)-5-(4-(1-(4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methylbenzamido)cyclopropyl)quinolin-2-yl)-N,N-dimethyl-1H-pyrazole-3-carboxamide, ENT-1;

rel-(R)-5-(4-(1-(4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methylbenzamido)cyclopropyl)quinolin-2-yl)-N,N-dimethyl-1H-pyrazole-3-carboxamide, ENT-2;

rel-(R)-4-(2-methoxy-1-(oxazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)benzamide, ENT-1;

rel-(R)-4-(2-methoxy-1-(oxazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclo-propyl)benzamide, ENT-2;

rel-(R)-4-(2-methoxy-1-(oxazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)benzamide, ENT-1;

2-methyl-N-(1-(2-(1-((methylsulfonyl)methyl)-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-4-((thiazol-4-ylmethoxy)methyl)benzamide;

N,N-dimethyl-5-(4-(1-(2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamido)cyclopropyl)quinolin-2-yl)-1H-pyrazole-3-carboxamide;

2-methyl-N-(1-(2-(1-methyl-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-4-((oxazol-4-ylmethoxy)methyl)benzamide;

2-methyl-N-(1-(7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)-4-((oxazol-4-ylmethoxy)methyl)benzamide;

N,N-dimethyl-5-(4-(1-(2-methyl-4-((oxazol-4-ylmethoxy)methyl)benzamido)cyclopropyl)quinolin-2-yl)-1H-pyrazole-3-carboxamide;

N-methyl-5-(4-(1-(2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamido)cyclopropyl)quinolin-2-yl)-1H-pyrazole-3-carboxamide;

2-methyl-N-(1-(2-methyl-7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)-4-((oxazol-4-ylmethoxy)methyl)benzamide;

5-(4-(1-(2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamido)cyclo-propyl)quinolin-2-yl)-1H-pyrazole-3-carboxamide;

N,N-dimethyl-5-(5-(1-(2-methyl-4-((oxazol-4-ylmethoxy)methyl)benzamido)cyclopropyl) quinolin-7-yl)-1H-pyrazole-3-carboxamide;

N,N-dimethyl-5-(5-(1-(2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamido)cyclopropyl)quinolin-7-yl)-1H-pyrazole-3-carboxamide;

rel-(R)-4-(2-methoxy-1-(oxazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclo-propyl)benzamide, ENT-1;

rel-(R)-4-(2-methoxy-1-(oxazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclo-propyl)benzamide, ENT-2;

N-(2-hydroxy-2-methylpropyl)-N-methyl-5-(4-(1-(2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamido)cyclopropyl) quinolin-2-yl)-1H-pyrazole-3-carboxamide;

rel-(R)-5-(5-(1-(4-(2-methoxy-1-(oxazol-4-ylmethoxy)ethyl)-2-methylbenzamido)cyclopropyl)quinolin-7-yl)-N,N-dimethyl-1H-pyrazole-3-carboxamide, ENT-1;

rel-(R)-5-(5-(1-(4-(2-methoxy-1-(oxazol-4-ylmethoxy)ethyl)-2-methylbenzamido)cyclopropyl)quinolin-7-yl)-N,N-dimethyl-1H-pyrazole-3-carboxamide, ENT-1;

rel-(R)-5-(5-(1-(4-(2-methoxy-1-(thiazol-4-ylmethoxy)ethyl)-2-methylbenzamido)cyclopropyl)quinolin-7-yl)-N,N-dimethyl-1H-pyrazole-3-carboxamide, ENT-1;

N,N-dimethyl3-(4-{4-[1-(4-{[(1,3-thiazol-4-yl)methoxy]methyl}-2-toluoylamino)cyclopropyl]-2-quinolyl}-1-pyrazolyl)propionamide;

N,N-dimethyl2-methyl-2-(4-{4-[1-(4-{[(1,3-thiazol-4-yl)methoxy]methyl}-2-toluoylamino)cyclopropyl]-2-quinolyl}-1-pyrazolyl)propionamide;

N-ethyl-N-methyl(4-{4-[1-(4-{[(1,3-thiazol-4-yl)methoxy]methyl}-2-toluoylamino)cyclopropyl]-2-quinolyl}-1-pyrazolyl)acetamide; and

rel-(R)-4-(2-methoxy-1-(oxazol-4-ylmethoxy)ethyl)-2-methyl-N-(1-(2-methyl-7-(1-methyl-1H-pyrazol-4-yl)quinolin-5-yl)cyclopropyl)benzamide, ENT-1;

or a pharmaceutically acceptable salt thereof.

14 . A compound of claim 1 which is selected from the group consisting of:

N-(1-(2-(1-(2-(dimethylamino)-2-oxoethyl)-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamide;

N,N-dimethyl-5-(4-(1-(2-methyl-4-((thiazol-4-ylmethoxy)methyl)benzamido)cyclopropyl) quinolin-2-yl)-1H-pyrazole-3-carboxamide;

N,N-dimethyl-5-(5-(1-(2-methyl-4-((oxazol-4-ylmethoxy)methyl)benzamido)cyclopropyl) quinolin-7-yl)-1H-pyrazole-3-carboxamide; and

N-(1-(2-(1-(2-(dimethylamino)-2-oxoethyl)-1H-pyrazol-4-yl)quinolin-4-yl)cyclopropyl)-2-methyl-4-((pyridin-2-ylmethoxy)methyl)benzamide;

or a pharmaceutically acceptable salt thereof.

15 . A pharmaceutical composition comprising a compound of any one of claims 1 to 14 , or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable excipient.

16 . A method for treating a viral infection, comprising administering to a subject in need thereof a therapeutically effective amount of a compound of any one of claims 1 to 14 , or a pharmaceutically acceptable salt thereof.

17 . A method for treating a viral infection of claim 16 , wherein the compound of any one of claims 1 to 14 , or a pharmaceutically acceptable salt thereof, is administered as a single agent.

18 . A method for treating a viral infection of claim 16 , further comprising administering a therapeutically effective amount of an additional therapeutic agent selected from the list consisting of viral RNA polymerase inhibitors, Mpro inhibitors, nucleoside inhibitors, host factor inhibitors, other PLpro inhibitors and metabolism boosting agents.

19 . A method for treating a viral infection of any one of claims 16 to 18 , wherein said viral infection is a coronavirus infection.

20 . A method for treating a viral infection of claim 19 , wherein said coronavirus infection is COVID-19.

21 . A compound of any one of claims 1 to 14 , for use as a medicament.

22 . A compound of any one of claims 1 to 14 , for use in the treatment of a viral infection.

23 . Use of a compound of any one of claims 1 to 14 for the manufacture of a medicament for the treatment of a viral infection.

24 . A method for the treatment of a disorder mediated by the papain-like protease in a subject, comprising administering to the subject in need thereof a compound of any one of claims 1 to 14 , or a pharmaceutically acceptable salt thereof, in an amount that is effective for treating the disorder.