Discovery of 4-ethoxy-7H-pyrrolo[2,3-d]pyrimidin-2-amines as potent, selective and orally bioavailable LRRK2 inhibitors

Abstract Inhibition of LRRK2 kinase activity with small molecules has emerged as a potential novel therapeutic treatment for Parkinson’s disease. Herein we disclose the discovery of a 4-ethoxy-7 H -pyrrolo[2,3- d ]pyrimidin-2-amine series as potent LRRK2 inhibitors identified through a kinase-focused set screening. Optimization of the physicochemical properties and kinase selectivity led to the discovery of compound 7 , which exhibited potent in vitro inhibition of LRRK2 kinase activity, good physicochemical properties and kinase selectivity across the kinome. Moreover, compound 7 was able to penetrate into the CNS, and in vivo pharmacology studies revealed significant inhibition of Ser935 phosphorylation in the brain of both rats (30 and 100 mg/kg) and mice (45 mg/kg) following oral administration.