Optimisation of novel 4, 8-disubstituted dihydropyrimido[5,4-b][1,4]oxazine derivatives as potent GPR 119 agonists

GPR119 is a promising target for discovery of anti-type 2 diabetes mellitus agents. We described the optimisation of a novel series of pyrimido[5,4-b][1,4]oxazine derivatives as GPR119 agonists. Most designed compounds exhibited good agonistic activities. Among them, compound 10 and 15 demonstrated the potent EC(50) values (13 and 12 nM, respectively) and strong inherent activities. Moreover, significant hypoglycaemic effect of compound 15 was observed by reducing the blood glucose AUC(0–2h) at the dose of 30 mg/kg, which is stronger than Vildagliptin (23.4% reduction vs. 17.9% reduction).