A potent, selective glucagon receptor antagonist 9m, N-[(4-{(1 S)-1-[3-(3, 5-dichlorophenyl)- 5-(6-methoxynaphthalen-2-yl)-1 H-pyrazol-1-yl] ethyl} phenyl) carbonyl]-β-alanine, was discovered by optimization of a previously identified lead. Compound 9m is a reversible and competitive antagonist with high binding affinity (IC50 of 6.6 nM) and functional cAMP activity (IC50 of 15.7 nM). It is selective for glucagon receptor relative to other family B ...