A compound of formula I where: R 1 is CO 2 R 5 or CONR 6 R 7; R 2 is furanyl, pyrrolyl, thienyl, pyrazolyl, isoxazolyl, isothiazolyl, imidazolyl, oxazolyl, thiazolyl, oxadiazolyl, triazolyl, or tetrazolyl, and is substituted with 0-2 substituents selected from oxo, amino, alkylthio, alkyl, and haloalkyl, and 1 substituent selected from CO 2 R 5, CON(R 12) 2, and COR 13; R 3 is hydrogen, halo, alkyl, alkenyl, hydroxy, benzyloxy, or alkoxy; R 4 is cycloalkyl; R 5 is hydrogen or alkyl; R 6 is hydrogen, alkyl, alkylSO 2, cycloalkylSO 2, haloalkylSO 2, (R 9)(R 10)NSO 2, or (R 11)SO 2; R 7 is hydrogen or alkyl; R 8 is hydrogen, alkyl, cycloalkyl, (cycloalkyl)alkyl, alkylcarbonyl, cycloalkylcarbonyl, haloalkylcarbonyl, alkoxycarbonyl, alkylSO 2, cycloalkylSO 2, haloalkylSO 2, aminocarbonyl, (alkylamino)carbonyl, (dialkylamino)carbonyl, benzyl, benzyloxycarbonyl, or pyridinyl; R 9 is hydrogen or alkyl; R 10 is hydrogen or alkyl; R 11 is azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, homopiperidinyl, homopiperazinyl, or homomorpholinyl, and is substituted with 0-1 alkyl substituents; R 12 is hydrogen, alkyl, alkoxyalkyl, aminoalkyl, (alkylamino)alkyl, (dialkylamino)alkyl, or (R 11)alkyl; R 13 is azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, homopiperidinyl, homopiperazinyl, or homomorpholinyl, and is substituted with 0-3 substituents selected from alkyl, alkoxyalkyl, amino, alkylamino, dialkylamino, R 11, aminoalkyl, (alkylamino)alkyl, (dialkylamino)alkyl, (R 11)alkyl, or CO 2 R 5; or R 13 is or or R 13 is or R 13 is a [4.3.0] or [3.3.0] bicyclic diamine attached to the carbonyl through one nitrogen, and is substituted with 0-2 R 8 substituents; or R 13 is or R 14 is hydrogen, alkyl, cycloalkyl, (cycloalkyl)alkyl, aminoalkyl, (alkylamino)alkyl, (dialkylamino)alkyl, or benzyl; R 15 is is hydrogen, alkyl, cycloalkyl, (cycloalkyl)alkyl, aminoalkyl, (alkylamino)alkyl, (dialkylamino)alkyl, or benzyl; or NR 14 R 15 taken together is azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, N-(alkyl)piperazinyl, morpholinyl, thiomorpholinyl, homopiperidinyl, or homomorpholinyl; R 16 is hydrogen or alkyl; R 17 is hydrogen, alkyl, or cycloalkyl; and X is methylene, a bond, or absent; or a pharmaceutically acceptable salt thereof. R 1 is CO 2 R 5 or CONR 6 R 7; R 2 is furanyl, pyrrolyl, thienyl, pyrazolyl, isoxazolyl, isothiazolyl, imidazolyl, oxazolyl, thiazolyl, oxadiazolyl, triazolyl, or tetrazolyl, and is substituted with 0-2 substituents selected from oxo, amino, alkylthio, alkyl, and haloalkyl, and 1 substituent selected from CO 2 R 5, CON(R 12) 2, and COR 13; R 3 is hydrogen, halo, alkyl, alkenyl, hydroxy, benzyloxy, or alkoxy; R 4 is cycloalkyl; R 5 is hydrogen or alkyl; R 6 is hydrogen, alkyl, alkylSO 2, cycloalkylSO 2, haloalkylSO 2, (R 9)(R 10)NSO 2, or (R 11)SO 2; R 7 is hydrogen or alkyl; R 8 is hydrogen, alkyl, cycloalkyl, (cycloalkyl)alkyl, alkylcarbonyl, cycloalkylcarbonyl, haloalkylcarbonyl, alkoxycarbonyl, alkylSO 2, cycloalkylSO 2, haloalkylSO 2, aminocarbonyl, (alkylamino)carbonyl, (dialkylamino)carbonyl, benzyl, benzyloxycarbonyl, or pyridinyl; R 9 is hydrogen or alkyl; R 10 is hydrogen or alkyl; R 11 is azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, homopiperidinyl, homopiperazinyl, or homomorpholinyl, and is substituted with 0-1 alkyl substituents; R 12 is hydrogen, alkyl, alkoxyalkyl, aminoalkyl, (alkylamino)alkyl, (dialkylamino)alkyl, or (R 11)alkyl; R 13 is azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, homopiperidinyl, homopiperazinyl, or homomorpholinyl, and is substituted with 0-3 substituents selected from alkyl, alkoxyalkyl, amino, alkylamino, dialkylamino, R 11, aminoalkyl, (alkylamino)alkyl, (dialkylamino)alkyl, (R 11)alkyl, or CO 2 R 5; or R 13 is or or R 13 is or R 13 is a [4.3.0] or [3.3.0] bicyclic diamine attached to the carbonyl through one nitrogen, and is substituted with 0-2 R 8 substituents; or R 13 is or R 14 is hydrogen, alkyl, cycloalkyl, (cycloalkyl)alkyl, aminoalkyl, (alkylamino)alkyl, (dialkylamino)alkyl, or benzyl; R 15 is is hydrogen, alkyl, cycloalkyl, (cycloalkyl)alkyl, aminoalkyl, (alkylamino)alkyl, (dialkylamino)alkyl, or benzyl; or NR 14 R 15 taken together is azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, N-(alkyl)piperazinyl, morpholinyl, thiomorpholinyl, homopiperidinyl, or homomorpholinyl; R 16 is hydrogen or alkyl; R 17 is hydrogen, alkyl, or cycloalkyl; and X is methylene, a bond, or absent; or a pharmaceutically acceptable salt thereof.