Development of an improved and facile synthesis route of the FGFR inhibitor erdafitinib

A facile and practical synthetic route for erdafitinib has been developed. In this route, the key intermediate N1-(3,5-dimethoxyphenyl)-N2-isopropylethane-1,2-diamine (12) was prepared from readily available staring materials, 3,5-dimethoxyaniline (5) and 2-bromoethylamine hydrobromide (16), through a novel two-step process with an overall yield of 70%. Erdafitinib was subsequently synthesized from compound 12 and 7-bromo-2-(1-methyl-1H-pyrazol-4-yl)quinoxaline (4) in 80% yield and 99% purity. This alternative procedure offers an economical and efficient route to produce erdafitinib.