A compound of Formula: or a salt thereof, wherein: R 1 is H, Cl, Br, -CN, C 1-4 alkyl, C 2-3 alkenyl, C 1-3 alkoxy, -C OH, -C O(C 1-3 alkyl), -C NR a R a, -NR a R a, -NR a C O(C 1-4 alkyl), or -NR a C NR a (C 1-4 alkyl); each R a is independently H or C 1-2 alkyl; R 2 is C 1-6 alkyl, C 1-4 cyanoalkyl, C 1-4 fluoroalkyl, C 2-4 alkenyl, -(CH 2) 1-3 CH=CF 2, C 3-5 alkynyl, -(CH 2) 1-4 O(C 1-3 alkyl), -(CH 2) 1-4 O(CH 2) 1-3 O(C 1-3 alkyl), -(CH 2) 1-3 C (C 1-3 alkyl), -(CH 2) 1-3 C O(C 1-3 alkyl), -(CH 2) 1-3 R b, -(CH 2) 1-3 OR b, or -(CH 2) 1-3 OCH 2 R b; R b is C 3-6 cycloalkyl or dioxanyl, each substituted with zero to 2 substituents independently selected from F, -CN, -CH 3, and -OCH 3; R 3 is H, F, Cl, Br, -CN, C 1-3 alkyl, C 1-3 fluoroalkyl, -NO 2, -C (C 1-3 alkyl), -C O(C 1-3 alkyl), or -C (C 1-3 fluoroalkyl); R 4 is: (a) 2,3-dihydro-1H-indenyl substituted with zero to 2 substituents independently selected from F, Cl, -OH, C 1-2 alkyl, C 1-2 fluoroalkyl, C 1-2 alkoxy, and -OCH 2 CH=CH 2; or (b) -CH 2 Ry, -C(CH 3) 2 Ry, -CHR x R y, -CH 2 CH R x, -CH(CH 3)(CH 2 CH 2 OCH 3), or C 3-6 cycloalkyl substituted with fluorophenyl; R x is C 1-6 alkyl, C 1-3 hydroxyalkyl, C 1-2 aminoalkyl, C 3-6 cycloalkyl, or phenyl substituted with zero to 2 substituents independently selected from F, Cl, -OH, C 1-3 alkyl, C 1-2 fluoroalkyl, C 1-2 alkoxy, -OCH 2 CH=CH 2, and -OCH 2 C≡CH; R y is 1,3-benzodiazolyl, indazolyl, indolyl, indolinyl, naphthalenyl, oxoindolinyl, pyridinyl, pyrimidinyl, or phenyl, each substituted with zero to 3 substituents independently selected from F, Cl, Br, -OH, -CN, C 1-6 alkyl, C 1-3 fluoroalkyl, C 1-3 alkoxy, C 1-3 fluoroalkoxy, -OCH 2 CH=CH 2, -OCH 2 C≡CH, -OCH 2 (cyanopyridinyl), -NR c R c, -NR a S 2 (C 1-3 alkyl), -NR a C (C 1-3 alkyl), -NR a C O(C 1-4 alkyl), -NR a C R d, -NR a C NR a R d, and R d; each R c is independently H or C 1-2 alkyl; and R d is phenyl substituted with zero to 1 substituent selected from Cl, -CH 3, and -OCH 3. R 1 is H, Cl, Br, -CN, C 1-4 alkyl, C 2-3 alkenyl, C 1-3 alkoxy, -C OH, -C O(C 1-3 alkyl), -C NR a R a, -NR a R a, -NR a C O(C 1-4 alkyl), or -NR a C NR a (C 1-4 alkyl); each R a is independently H or C 1-2 alkyl; R 2 is C 1-6 alkyl, C 1-4 cyanoalkyl, C 1-4 fluoroalkyl, C 2-4 alkenyl, -(CH 2) 1-3 CH=CF 2, C 3-5 alkynyl, -(CH 2) 1-4 O(C 1-3 alkyl), -(CH 2) 1-4 O(CH 2) 1-3 O(C 1-3 alkyl), -(CH 2) 1-3 C (C 1-3 alkyl), -(CH 2) 1-3 C O(C 1-3 alkyl), -(CH 2) 1-3 R b, -(CH 2) 1-3 OR b, or -(CH 2) 1-3 OCH 2 R b; R b is C 3-6 cycloalkyl or dioxanyl, each substituted with zero to 2 substituents independently selected from F, -CN, -CH 3, and -OCH 3; R 3 is H, F, Cl, Br, -CN, C 1-3 alkyl, C 1-3 fluoroalkyl, -NO 2, -C (C 1-3 alkyl), -C O(C 1-3 alkyl), or -C (C 1-3 fluoroalkyl); R 4 is: (a) 2,3-dihydro-1H-indenyl substituted with zero to 2 substituents independently selected from F, Cl, -OH, C 1-2 alkyl, C 1-2 fluoroalkyl, C 1-2 alkoxy, and -OCH 2 CH=CH 2; or (b) -CH 2 Ry, -C(CH 3) 2 Ry, -CHR x R y, -CH 2 CH R x, -CH(CH 3)(CH 2 CH 2 OCH 3), or C 3-6 cycloalkyl substituted with fluorophenyl; (a) 2,3-dihydro-1H-indenyl substituted with zero to 2 substituents independently selected from F, Cl, -OH, C 1-2 alkyl, C 1-2 fluoroalkyl, C 1-2 alkoxy, and -OCH 2 CH=CH 2; or (b) -CH 2 Ry, -C(CH 3) 2 Ry, -CHR x R y, -CH 2 CH R x, -CH(CH 3)(CH 2 CH 2 OCH 3), or C 3-6 cycloalkyl substituted with fluorophenyl; R x is C 1-6 alkyl, C 1-3 hydroxyalkyl, C 1-2 aminoalkyl, C 3-6 cycloalkyl, or phenyl substituted with zero to 2 substituents independently selected from F, Cl, -OH, C 1-3 alkyl, C 1-2 fluoroalkyl, C 1-2 alkoxy, -OCH 2 CH=CH 2, and -OCH 2 C≡CH; R y is 1,3-benzodiazolyl, indazolyl, indolyl, indolinyl, naphthalenyl, oxoindolinyl, pyridinyl, pyrimidinyl, or phenyl, each substituted with zero to 3 substituents independently selected from F, Cl, Br, -OH, -CN, C 1-6 alkyl, C 1-3 fluoroalkyl, C 1-3 alkoxy, C 1-3 fluoroalkoxy, -OCH 2 CH=CH 2, -OCH 2 C≡CH, -OCH 2 (cyanopyridinyl), -NR c R c, -NR a S 2 (C 1-3 alkyl), -NR a C (C 1-3 alkyl), -NR a C O(C 1-4 alkyl), -NR a C R d, -NR a C NR a R d, and R d; each R c is independently H or C 1-2 alkyl; and R d is phenyl substituted with zero to 1 substituent selected from Cl, -CH 3, and -OCH 3.