Allosteric agonists and positive allosteric modulators of Glucagon-like peptide 1 receptor

A compound of formula:

• wherein:
• each occurrence of R1 is independently selected optionally substituted C1-C6 alkyl;
• R2 and R3 are each independently selected from the group consisting of H and optionally substituted C1-C6 alkyl;
• R4 is selected from the group consisting of —NH2, —NH(C1-C6 alkyl), —N(C1-C6 alkyl)(C1-C6 alkyl), and optionally substituted C1-C6 alkoxy, or
• R2 is absent and R3 and R4 combine with ═C(XR′)—N(R″)—* to form a ring,
• wherein the bond marked as * is with the carbonyl group in the compound;
• X is selected from the group consisting of O, S, and NR;
• R is H;
• each occurrence of R′ is independently selected from the group consisting of H, optionally substituted C1-C6 alkyl, (CH2)nC(═O)R5, and (CH2CH2O)nC(═O)R5, wherein each n is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10;
• each occurrence of R5 is independently selected optionally substituted phenyl;
• each occurrence of R″ is independently selected from the group consisting of hydrogen, —NH2, —NH(C1-C6 alkyl), and —N(C1-C6 alkyl)(C1-C6 alkyl);
• wherein each optional substituent is independently selected from the group consisting of fluorine, chlorine, bromine, iodine, —CN, —NH2, —OH, —NH(CH3), —N(CH3)2, —CH3, —CH2CH3, —CH(CH3)2, —CF3, —CH2CF3, —OCH3, —OCH2CH3, —OCH(CH3)2, —OCF3, —OCH2CF3, —S(═O)2—CH3, —C(═O)NH2, —C(═O)—NHCH3, —NHC(═O)NHCH3, —C(═O)CH3, and —C(═O)OH;
• or a salt, solvate, stereoisomer, geometric isomer, or tautomer thereof.