Discovery of furan-2-carbohydrazides as orally active glucagon receptor antagonists

Furan-2-carbohydrazides were found as orally active glucagon receptor antagonists. Starting from the hit compound 5, we successfully determined the structure activity relationships of a series of derivatives obtained by modifying the acidity of the phenol. We identified the ortho-nitrophenol as a good scaffold for glucagon receptor inhibitory activity. Our efforts have led to the discovery of compound 7l as a potent glucagon receptor antagonist with good bioavailability and satisfactory long half-life.