N-substituted-dioxocyclobutenylamino-3-hydroxy-picolinamides useful as CCR6 inhibitors

A method of treating a condition comprising administering to a subject in need thereof a therapeutically effective amount of a compound of Formula (IIA) or Formula (IIB):

• or a pharmaceutically acceptable salt thereof,
• wherein:
• R1 and R2 are each independently H or (C1-C6)alkyl, or R1 and R2 taken together with the nitrogen atom to which they are attached form a 4-, 5-, or 6-membered heterocycle containing one N heteroatom and optionally 1 or 2 additional heteroatoms selected from the group consisting of O, N, and S, wherein the heterocycle is optionally substituted with 1, 2, or 3 (C1-C4)alkyl groups;
• R3 is H, (C1-C6)alkyl, (C1-C4)alkylcarbonyl, —C(═O)CH═CHCO2H, —SO2NH2, —CH2OC(=O)(C1-C4)alkyl, —CH2OP(=O)(OH)2, or —C(═O)NRARB, wherein the (C1-C4)alkylcarbonyl is optionally substituted with —CO2H or —NH2, wherein the —CH2OC(=O)(C1-C4)alkyl is optionally substituted with —NH2, and wherein RA and RB are independently H or (C1-C6)alkyl;
• R4 is H, (C1-C4)alkyl, (C3-C4) cycloalkyl, (C3-C4) cycloalkyl (C1-C4)alkyl, or halo(C1-C4)alkyl;
• R5 and R6 are each independently H, deuterium, (C2-C4)alkenyl, (C1-C4)alkoxy, (C1-C4)alkyl, (C1-C4)alkyl-d1-9, (C3-C4) cycloalkyl, (C3-C4) cycloalkyl (C1-C4)alkyl, cyano, halogen, halo(C1-C4)alkoxy, halo(C1-C4)alkyl, or hydroxy (C1-C4)alkyl;
• and
• B is
• R7 is —F, —CN, (C1-C3)alkyl, (C1-C3)alkyl-d1-7, or halo(C1-C3)alkyl;
• R8 at each occurrence is independently deuterium, —F, —Cl, —Br, or —I, or two R8s attached to the same carbon atom form a (C3-C5) cycloalkyl group;
• and
• n is 0, 1, 2, 3, or 4,
• wherein the condition is selected from the group consisting of psoriasis, ulcerative colitis, Crohn's disease, inflammatory bowel disease, psoriatic arthritis, and rheumatoid arthritis.