Novel Pyrimidines as Multitarget Protein Tyrosine Kinase Inhibitors for the Treatment of Idiopathic Pulmonary Fibrosis (IPF)

Abstract A new class of pyrimidine derivatives were identified as potent protein tyrosine kinase (PTK) inhibitors for the treatment of idiopathic pulmonary fibrosis (IPF). Most of these small‐molecule inhibitors displayed strong enzymatic activity against BTK and JAK3 kinases at concentrations lower than 10 nM. The representative compound N ‐(3‐((5‐chloro‐2‐(4‐((1‐morpholino)acetylamino)phenylamino)‐4‐pyrimidinyl)amino)phenyl)acrylamide ( 6 a ) also exhibited high inhibitory potency toward both BTK and JAK kinase families, as well as ErbB4, at a concentration of 10 nM, achieving rates of inhibition higher than 57 %. Additionally, in vivo biological evaluations showed that 6 a can remarkably decrease the severity of IPF disease. All these investigations suggested that the multi‐PTK inhibitor 6 a may serve as a promising agent for the treatment of IPF.