1202759-91-8

A solution of tert-butyl 3-((5-fluoro-2-((4-(2-methoxyethoxy)phenyl)amino)pyrimidin-4-yl)amino)phenylcarbamate (1.2 g) in dichloromethane (DCM, 10 mL) was sequentially added to a 25 mL three-necked round-bottomed flask (RBF) equipped with a magnetic stirrer. Trifluoroacetic acid (TFA, 6.0 mL) was added dropwise to the reaction mixture at 0 °C. The reaction mixture was stirred at 0 °C for 45 min. The reaction process was monitored by thin layer chromatography (TLC) using ethyl acetate: hexane (7:3) as the mobile phase. After completion of the reaction, the reaction mixture was quenched in water and neutralized with sodium bicarbonate. The mixture was extracted with dichloromethane. The organic layer was washed with brine, dried over anhydrous sodium sulfate and concentrated to dryness at 40 °C under reduced pressure to afford 0.94 g N4-(3-aminophenyl)-5-fluoro-N2-(4-(2-methoxyethoxy)phenyl)pyrimidine-2,4-diamine, which was used in the next reaction without further purification.

[1] Patent: US2014/179720, 2014, A1. Location in patent: Paragraph 0380; 0382
[2] Patent: US2015/174128, 2015, A1. Location in patent: Paragraph 0716
[3] Patent: WO2009/158571, 2009, A1. Location in patent: Page/Page column 190; 192