A compound of Formula 1, a stereoisomer thereof or a pharmaceutically acceptable salt of the compound or stereoisomer, wherein: R 1 and R 2 are each independently selected from phenyl, C 3-5 heteroaryl, -OR 4, and -N(R 4)R 5, wherein each phenyl and C 3-5 heteroaryl is independently substituted with from 0 to 3 R a, and each C 3-5 heteroaryl has 5 or 6 ring atoms of which 1 or 2 are heteroatoms independently selected from N, O, and S; each R a is independently selected from halo, -CN, R 3, and R 4; each R 3 is independently selected from - OR 4, -N(R 4)R 5, -NR 4 C R 6, -NR 4 C OR 5, -C OR 4, -C N(R 4)R 5, -C N(R 4) OR 5, -C N(R 4)S 2 R 6, -N(R 4)S 2 R 6, -SR 4, -S R 6, -S 2 R 6, and -S 2 N(R 4)R 5; each R 4 and R 5 is independently selected from (a) C 1-6 alkyl, C 2-6 alkenyl, and C 2-6 alkynyl, each substituted with from 0 to 3 R b, and (b) C 3-8 cycloalkyl-(CH 2) m -, C 2-6 heterocyclyl-(CH 2) m -, C 6-14 aryl-(CH 2) m -, and C 1-9 heteroaryl-(CH 2) m -, each substituted with from 0 to 3 R c; each R 6 is independently selected from (a) C 1-6 alkyl, which is substituted with from 0 to 3 R b, and (b) C 3-8 cycloalkyl-(CH 2) m -, C 2-6 heterocyclyl-(CH 2) m -, C 6-14 aryl-(CH 2) m -, and C 1-9 heteroaryl-(CH 2) m -, each substituted with from 0 to 3 R d; each R b is independently selected from halo, -CN, and R 7; each R c is independently selected from (a) halo, -CN, and R 7, and (b) C 1-6 alkyl, C 2-6 alkenyl, and C 2-6 alkynyl, each substituted with from 0 to 3 R b; each R d is independently selected from (a) halo, -CN, and R 7, and (b) C 1-6 alkyl, which is substituted with from 0 to 3 R b; each R 7 is independently selected from - OR 8, -N(R 8)R 9, -NR 8 C R 9, -NR 8 C OR 9, -C OR 8, -C N(R 8)R 9, -C N(R 8) OR 9, -C N(R 8)S 2 R 9, -N(R 8)S 2 R 9, -SR 8, -S R 8, -S 2 R 8, and -S 2 N(R 8)R 9; each R 8 and R 9 is independently selected from C 1-6 alkyl, C 3-8 cycloalkyl-(CH 2) m -, and C 2-6 heterocyclyl-(CH 2) m -, each substituted with from 0 to 3 substituents independently selected from halo and -CN; and each m is independently selected from 0, 1, 2, 3, and 4; wherein each heteroaryl moiety listed in R 4, R 5, and R 6 independently has from 1 to 4 heteroatoms independently selected from N, O, and S, and each heterocyclyl moiety listed in R 4, R 5, R 6, and R 8 independently has from 1 to 4 heteroatoms independently selected from N, O, and S. R 1 and R 2 are each independently selected from phenyl, C 3-5 heteroaryl, -OR 4, and -N(R 4)R 5, wherein each phenyl and C 3-5 heteroaryl is independently substituted with from 0 to 3 R a, and each C 3-5 heteroaryl has 5 or 6 ring atoms of which 1 or 2 are heteroatoms independently selected from N, O, and S; each R a is independently selected from halo, -CN, R 3, and R 4; each R 3 is independently selected from - OR 4, -N(R 4)R 5, -NR 4 C R 6, -NR 4 C OR 5, -C OR 4, -C N(R 4)R 5, -C N(R 4) OR 5, -C N(R 4)S 2 R 6, -N(R 4)S 2 R 6, -SR 4, -S R 6, -S 2 R 6, and -S 2 N(R 4)R 5; each R 4 and R 5 is independently selected from (a) C 1-6 alkyl, C 2-6 alkenyl, and C 2-6 alkynyl, each substituted with from 0 to 3 R b, and (b) C 3-8 cycloalkyl-(CH 2) m -, C 2-6 heterocyclyl-(CH 2) m -, C 6-14 aryl-(CH 2) m -, and C 1-9 heteroaryl-(CH 2) m -, each substituted with from 0 to 3 R c; (a) C 1-6 alkyl, C 2-6 alkenyl, and C 2-6 alkynyl, each substituted with from 0 to 3 R b, and (b) C 3-8 cycloalkyl-(CH 2) m -, C 2-6 heterocyclyl-(CH 2) m -, C 6-14 aryl-(CH 2) m -, and C 1-9 heteroaryl-(CH 2) m -, each substituted with from 0 to 3 R c; each R 6 is independently selected from (a) C 1-6 alkyl, which is substituted with from 0 to 3 R b, and (b) C 3-8 cycloalkyl-(CH 2) m -, C 2-6 heterocyclyl-(CH 2) m -, C 6-14 aryl-(CH 2) m -, and C 1-9 heteroaryl-(CH 2) m -, each substituted with from 0 to 3 R d; (a) C 1-6 alkyl, which is substituted with from 0 to 3 R b, and (b) C 3-8 cycloalkyl-(CH 2) m -, C 2-6 heterocyclyl-(CH 2) m -, C 6-14 aryl-(CH 2) m -, and C 1-9 heteroaryl-(CH 2) m -, each substituted with from 0 to 3 R d; each R b is independently selected from halo, -CN, and R 7; each R c is independently selected from (a) halo, -CN, and R 7, and (b) C 1-6 alkyl, C 2-6 alkenyl, and C 2-6 alkynyl, each substituted with from 0 to 3 R b; (a) halo, -CN, and R 7, and (b) C 1-6 alkyl, C 2-6 alkenyl, and C 2-6 alkynyl, each substituted with from 0 to 3 R b; each R d is independently selected from (a) halo, -CN, and R 7, and (b) C 1-6 alkyl, which is substituted with from 0 to 3 R b; (a) halo, -CN, and R 7, and (b) C 1-6 alkyl, which is substituted with from 0 to 3 R b; each R 7 is independently selected from - OR 8, -N(R 8)R 9, -NR 8 C R 9, -NR 8 C OR 9, -C OR 8, -C N(R 8)R 9, -C N(R 8) OR 9, -C N(R 8)S 2 R 9, -N(R 8)S 2 R 9, -SR 8, -S R 8, -S 2 R 8, and -S 2 N(R 8)R 9; each R 8 and R 9 is independently selected from C 1-6 alkyl, C 3-8 cycloalkyl-(CH 2) m -, and C 2-6 heterocyclyl-(CH 2) m -, each substituted with from 0 to 3 substituents independently selected from halo and -CN; and each m is independently selected from 0, 1, 2, 3, and 4; wherein each heteroaryl moiety listed in R 4, R 5, and R 6 independently has from 1 to 4 heteroatoms independently selected from N, O, and S, and each heterocyclyl moiety listed in R 4, R 5, R 6, and R 8 independently has from 1 to 4 heteroatoms independently selected from N, O, and S.