A compound of formula, or a salt thereof: wherein: R 1 is optionally substituted with one or more R W, wherein each R W is independently selected from the group consisting of C 1-10 alkyl, C 1-10 haloalkyl, halogen, -CN, - OR A, -C 1-10 alkylene-OR A, -CO-R A, -C 1-10 alkylene-CO-R A, -CO-OR A, -C 1-10 alkylene-CO-OR A, - CO-NHR A, -C 1-10 alkylene-CO-NHR A, -NR B R C, -C 1-10 alkylene-NR B R C, -NH-CO-C 1-4 alkyl, -C 1 - 10 alkylene-NH-CO-C 1-4 alkyl, phenyl, and phenyl substituted with 1, 2, 3, or 4 R D groups; R 2 is C 1-10 alkyl, C 1-10 haloalkyl, halogen, -CN, -OR A, -C 1-4 alkylene-OR A, -CO-R A, -C 1 - 4 alkylene-CO-R A, -CO-OR A, -C 1-4 alkylene-CO-OR A, -CO-NHR A, -C 1-4 alkylene-CO-NHR A, - NR B R C, -C 1-4 alkylene-NT B R C, -NH-CO-C 1-4 alkyl, -C 1-4 alkylene-NH-CO-C 1-4 alkyl, phenyl, phenyl substituted with 1, 2, 3, or 4 R D groups, -C≡C-R A, or -C≡C-C 1-4 alkylene-OR A, or two R 2 together with the carbon atoms of the moiety to which they are attached form a 5- or 6-membered fused ring; R 3 is C 1-10 alkyl, C 1-10 haloalkyl, halogen, -CN, -OR A, -C 1-4 alkylene-OR A, -CO-R A, -CO-OR A, or -CO-NHR A, or two R 3 together with the carbon atoms of the moiety to which they are attached form a 5- or 6-membered fused ring; R 4 is H or C 1-4 alkyl; p is 0, 1, 2, 3, or 4; q is 0, 1, 2, 3, or 4; R A at each occurrence is independently H, C 1-4 alkyl, or C 1-4 haloalkyl; R B and R C at each occurrence are independently H or C 1-4 alkyl, or R B and R C together with the N atom to which they are attached form a 5- or 6-membered heterocycle; and R D at each occurrence is independently C 1-4 alkyl, -OC 1-4 alkyl, -CN, or halogen, wherein the compound is not N-phenyl-2-(phenylsulfonamido)benzamide. R 1 is optionally substituted with one or more R W, wherein each R W is independently selected from the group consisting of C 1-10 alkyl, C 1-10 haloalkyl, halogen, -CN, - OR A, -C 1-10 alkylene-OR A, -CO-R A, -C 1-10 alkylene-CO-R A, -CO-OR A, -C 1-10 alkylene-CO-OR A, - CO-NHR A, -C 1-10 alkylene-CO-NHR A, -NR B R C, -C 1-10 alkylene-NR B R C, -NH-CO-C 1-4 alkyl, -C 1 - 10 alkylene-NH-CO-C 1-4 alkyl, phenyl, and phenyl substituted with 1, 2, 3, or 4 R D groups; R 2 is C 1-10 alkyl, C 1-10 haloalkyl, halogen, -CN, -OR A, -C 1-4 alkylene-OR A, -CO-R A, -C 1 - 4 alkylene-CO-R A, -CO-OR A, -C 1-4 alkylene-CO-OR A, -CO-NHR A, -C 1-4 alkylene-CO-NHR A, - NR B R C, -C 1-4 alkylene-NT B R C, -NH-CO-C 1-4 alkyl, -C 1-4 alkylene-NH-CO-C 1-4 alkyl, phenyl, phenyl substituted with 1, 2, 3, or 4 R D groups, -C≡C-R A, or -C≡C-C 1-4 alkylene-OR A, or two R 2 together with the carbon atoms of the moiety to which they are attached form a 5- or 6-membered fused ring; R 3 is C 1-10 alkyl, C 1-10 haloalkyl, halogen, -CN, -OR A, -C 1-4 alkylene-OR A, -CO-R A, -CO-OR A, or -CO-NHR A, or two R 3 together with the carbon atoms of the moiety to which they are attached form a 5- or 6-membered fused ring; R 4 is H or C 1-4 alkyl; p is 0, 1, 2, 3, or 4; q is 0, 1, 2, 3, or 4; R A at each occurrence is independently H, C 1-4 alkyl, or C 1-4 haloalkyl; R B and R C at each occurrence are independently H or C 1-4 alkyl, or R B and R C together with the N atom to which they are attached form a 5- or 6-membered heterocycle; and R D at each occurrence is independently C 1-4 alkyl, -OC 1-4 alkyl, -CN, or halogen, wherein the compound is not N-phenyl-2-(phenylsulfonamido)benzamide.