Substituted pyridopyrimidinonyl compounds useful as t cell activators

A compound of Formula (I):

• or a salt thereof, wherein:
• R1 is H, F, Cl, Br, —CN, —OH, C1-3 alkyl substituted with zero to 4 R1a, C3-4 cycloalkyl substituted with zero to 4 R1a, C1-3 alkoxy substituted with zero to 4 R1a, —NRaRa, —S(O)nRe, or —P(O)ReRe;
• each R1a is independently F, Cl, —CN, —OH, —OCH3, or —NRaRa;
• each Ra is independently H or C1-3 alkyl;
• each Re is independently C3-4 cycloalkyl or C1-3 alkyl substituted with zero to 4 R1a;
• R2 is H, C1-3 alkyl substituted with zero to 4 R2a, or C3-4 cycloalkyl substituted with zero to 4 R2a;
• each R2a is independently F, Cl, —CN, —OH, —O(C1-2 alkyl), C3-4 cycloalkyl, C3-4 alkenyl, or C3-4 alkynyl;
• R4 is —CH2R4a, —CH2CH2R4a, —CH2CHR4aR4d, —CHR4aR4b, or —CR4aR4bR4c;
• R4a and R4b are independently:
• (i) —CN or C1-6 alkyl substituted with zero to 4 substituents independently selected from F, Cl, —CN, —OH, —OCH3, —SCH3, C1-3 fluoroalkoxy, —NRaRa, —S(O)2Re, or —NRaS(O)2Re;
• (ii) C3_6 cycloalkyl, 4- to 10-membered heterocyclyl, phenyl, or 5-to 10-membered heteroaryl, each substituted with zero to 4 substituents independently selected from F, Cl, Br, —CN, —OH, C1-6 alkyl, C1-3 fluoroalkyl, C1-2 bromoalkyl, C1-2 cyanoalkyl, C1-4 hydroxyalkyl, (CH2)1-2O(C1-3 alkyl), C1-4 alkoxy, C1-3 fluoroalkoxy, C1-3 cyanoalkoxy, hydroxyalkyl), —O(CRxRx)1-3O(C1-3 alkyl), C1-3 fluoroalkoxy, —O(CH2)1-3NRcRc, —OCH2CH═CH2, —OCH2C≡CH, —C(O)(C1-4 alkyl), —C(O)OH, —C(O)O(C1-4 alkyl), —NRcRc, —CH2NRaRa, —NRaS(O)2(C1-3 alkyl), —NRaC(O)(C1-3 alkyl), —(CRxRx)0-2NRaC(O)O(C1-4 alkyl), —P(O)(C1-3 alkyl)2, —S(O)2(C1-3 alkyl), —(CRxRx)1-2(C3-4 cycloalkyl), —(CRxRx)1-2(morpholinyl), —(CRxRx)1-2(difluoromorpholinyl), —(CRxRx)1-2(dimethylmorpholinyl), —(CRxRx)1-2(oxaazabicyclo[2.2.1]heptanyl), (CRxRx)1-2(oxaazaspiro[3.3]heptanyl), —(CRxRx)1-2(methylpiperazinonyl), —(CRxRx)1-2(acetylpiperazinyl), —(CRxRx)1-2(piperidinyl), —(CRxRx)1-2(difluoropiperidinyl), —(CRxRx)1-2(methoxypiperidinyl), —(CRxRx)1-2(hydroxypiperidinyl), —O(CRxRx)0-2(C3-6 cycloalkyl), —O(CRxRx)0-2(methylcyclopropyl), —O(CRxRx)0-2((ethoxycarbonyl)cyclopropyl), —O(CRxRx)0-2(oxetanyl), —O(CRxRx)0-2(methylazetidinyl), —O(CRxRx)0-2(tetrahydropyranyl), —O(CRxRx)1-2(morpholinyl), —O(CRxRx)0-2(thiazolyl), cyclopropyl, cyanocyclopropyl, methylazetidinyl, acetylazetidinyl, (tert-butoxycarbonyl)azetidinyl, triazolyl, tetrahydropyranyl, morpholinyl, thiophenyl, methylpiperidinyl, dioxolanyl, pyrrolidinonyl, and Rd;
• or
• (iii) C1-4 alkyl substituted with one cyclic group selected from C3-6 cycloalkyl, 4- to 10-membered heterocyclyl, mono- or bicyclic aryl, or 5-to 10-membered heteroaryl, said cyclic group substituted with zero to 3 substituents independently selected from F, Cl, Br, —OH, —CN, C1-6 alkyl, C1-3 fluoroalkyl, C1-3 alkoxy, C1-3 fluoroalkoxy, —OCH2CH═CH2, —OCH2C≡CH, —NRcRc, —NRaS(O)2(C1-3 alkyl), —NRaC(O)(C1-3 alkyl), —NRaC(O)O(C1-4 alkyl), and C3-6 cycloalkyl;
• or R4a and R4b together with the carbon atom to which they are attached form a C3-6 cycloalkyl or a 3- to 6-membered heterocyclyl, each substituted with zero to 3 Rf;
• each Rf is independently F, Cl, Br, —OH, —CN, C1-6 alkyl, C1-3 fluoroalkyl, C1-3 alkoxy, C1-3 fluoroalkoxy, —OCH2CH═CH2, —OCH2C≡CH, —NRcRc, or a cyclic group selected from C3-6 cycloalkyl, 3- to 6-membered heterocyclyl, phenyl, monocyclic heteroaryl, and bicyclic heteroaryl, each cyclic group substituted with zero to 3 substituents independently selected from F, Cl, Br, —OH, —CN, C1-6 alkyl, C1-3 fluoroalkyl, C1-3 alkoxy, C1-3 fluoroalkoxy, and —NRcRc;
• R4c is C1-6 alkyl or C3-6 cycloalkyl, each substituted with zero to 4 substituents independently selected from F, Cl, —OH, C1-2 alkoxy, C1-2 fluoroalkoxy, and —CN;
• R4d is —OCH3;
• each Rc is independently H or C1-2 alkyl;
• Rd is phenyl substituted with zero to 1 substituent selected from F, Cl, —CN, —CH3, and —OCH3;
• each R5 is independently —CN, C1-6 alkyl substituted with zero to 4 Rg, C2-4 alkenyl substituted with zero to 4 Rg, C2-4 alkynyl substituted with zero to 4 Rg, C3-4 cycloalkyl substituted with zero to 4 Rg, phenyl substituted with zero to 4 Rg, oxadiazolyl substituted with zero to 3 Rg, pyridinyl substituted with zero to 4 Rg, —(CH2)1-2(4- to 10-membered heterocyclyl substituted with zero to 4 Rg), —(CH2)1-2NRcC(O)(C1-4 alkyl), —(CH2)1-2NRcC(O)O(C1-4 alkyl), —(CH2)1-2NRcS(O)2(C1-4 alkyl), —C(O)(C1-4 alkyl), —C(O)OH, —C(O)O(C1-4 alkyl), —C(O)O(C3-4 cycloalkyl), —C(O)NRaRa, or —C(O)NRa(C3-4 cycloalkyl);
• each Rg is independently F, Cl, —CN, —OH, C1-3 alkoxy, C1-3 fluoroalkoxy, —O(CH2)1-2O(C1-2 alkyl), or —NRcRc;
• m is zero, 1, 2, or 3;
• and
• n is zero, 1, or 2.