Hepatitis C virus inhibitors

1. A compound of formula (I)

or a pharmaceutically acceptable salt thereof, wherein

p is 1 or 2;

is a single or double bond;

R 1 is selected from

wherein “ ” denotes the point of attachment to the parent molecular moiety;

m is 0, 1, or 2;

n is 0, 1, 2, 3, 4, 5, or 6;

X 1 is selected from N, CH, and CR a ; wherein when X 1 is N then one of X 2 and X 3 is selected from N, CH, and CR a and the other is selected from CH and CR a ; and wherein when X 1 is selected from CH and CR a , then X 2 is selected from CH and CR a and X 3 is N;

X 2′ is selected from CH and CR a ;

each R a is independently selected from alkenyloxy, alkoxy, alkoxyalkoxy, alkyl, benzodioxanyl, carboxamido, carboxy, carboxyalkoxy, cyano, cycloalkylalkoxy, cycloalkyloxy, deuteroalkoxy, dialkylamino, halo, haloalkyl, haloalkoxy, haloalkoxycarbonyl, hydroxy, morpholinyl, phenyl, piperazinyl, pyrazolyl, and pyridinyl, pyrrolidinyl, wherein the morpholinyl, the phenyl, the piperazinyl, the pyridinyl, and the pyrrolidinyl are optionally substituted with one or two groups independently selected from alkoxy, alkyl, alkylsulfonyl, halo, haloalkoxy, haloalkyl, and morpholinyl; and wherein two adjacent R a groups, together with the carbon atoms to which they are attached, can optionally form a ring selected from dioxanyl, dioxolanyl, morpholinyl, pyranyl, and phenyl, wherein the ring is optionally substituted with one or two groups independently selected from alkyl and halo; provided that no more than one additional ring is formed;

R b is selected from alkoxyalkyl and alkyl;

R x is selected from methyl and ethyl;

R y and R z are independently selected from hydrogen and hydroxy; provided that when - - - - - is a double bond, R y and R z are each hydrogen;

R 2 is selected from hydrogen, alkyl, halo, haloalkoxy, haloalkyl, and hydroxyalkyl; and

R 3 is selected from hydrogen, alkoxyalkoxycarbonyl, alkoxycarbonyl, alkylaminocarbonyl, alkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylcarbonyl, cycloalkyloxycarbonyl, deuteroalkoxycarbonyl, deuterohaloalkoxycarbonyl, dialkylaminocarbonyl, dialkylaminocarbonylcarbonyl, haloalkoxycarbonyl, haloalkylaminocarbonyl, haloalkylcarbonyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl, phenylcarbonyl, and phenyloxycarbonyl, wherein the cycloalkyl part of the cycloalkylalkoxycarbonyl, the cycloalkylcarbonyl, and the cycloalkyloxycarbonyl, the heterocyclyl part of the heterocyclylcarbonyl and the heterocyclyloxycarbonyl, and the phenyl part of the phenylcarbonyl and the phenyloxycarbonyl, is optionally substituted with one, two, or three groups independently selected from alkyl, alkylamino, alkylcarbonyl, cycloalkyl, dialkylamino, halo, haloalkoxy, and haloalkyl; wherein the heterocycle and the heterocyclyl part of the heterocyclylcarbonyl and the heterocyclyloxycarbonyl is a four-, five-, or six-membered ring containing one heteroatom selected from oxygen and nitrogen and optionally an oxo group.

2. A compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein m is 1.

3. A compound of claim 1 , or a pharmaceutically acceptable salt thereof, wherein - - - - - is a double bond.

4. A compound of claim 3 , or a pharmaceutically acceptable salt thereof, wherein R x is methyl.

5. A compound of formula (II)

or a pharmaceutically acceptable salt thereof, wherein

n is 0, 1, 2, 3, 4, 5, or 6;

X 1 is selected from N, CH, and CR a ; wherein when X 1 is N then one of X 2 and X 3 is selected from N, CH, and CR a and the other is selected from CH and CR a ; and wherein when X 1 is selected from CH and CR a , then X 2 is selected from CH and CR a and X 3 is N;

R a is selected from methyl and ethyl;

each R 1 is independently selected from alkoxy, alkyl, carboxamido, carboxy, cyano, cycloalkyloxy, dialkylamino, halo, haloalkyl, haloalkoxy, phenyl, and pyridinyl, wherein the phenyl and the pyridinyl are optionally substituted with one or two groups independently selected from alkoxy, alkyl, halo, haloalkoxy, and haloalkyl;

R 2 is selected from hydrogen, alkyl, halo, and haloalkyl; and

R 3 is selected from alkoxycarbonyl, alkylcarbonyl, haloalkoxycarbonyl, haloalkylcarbonyl, and phenylcarbonyl, wherein the phenyl is optionally substituted with one or two groups independently selected from alkyl and halo.

6. A compound of formula (III)

or a pharmaceutically acceptable salt thereof, wherein

n is 0, 1, 2, 3, 4, 5, or 6;

each R 1 is independently selected from alkoxy, alkyl, carboxamido, carboxy, cyano, cycloalkyloxy, dialkylamino, halo, haloalkyl, haloalkoxy, and phenyl, wherein the phenyl is optionally substituted with one or two groups independently selected from alkoxy, alkyl, halo, haloalkoxy, and haloalkyl;

R 2 is selected from hydrogen, alkyl, halo, and haloalkyl; and

R 3 is selected from alkoxycarbonyl, alkylcarbonyl, haloalkoxycarbonyl, haloalkylcarbonyl, and phenylcarbonyl, wherein the phenyl is optionally substituted with one or two groups independently selected from alkyl and halo;

or a pharmaceutically acceptable salt thereof.

7. A composition comprising a compound of claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

8. A method of treating an HCV infection in a patient, comprising administering to the patient a therapeutically effective amount of a compound of claim 1 , or a pharmaceutically acceptable salt thereof.