The synthesis of Futibatinib is as follows:
2 methanesulfonate (25.0 g), water (69 mL), and acetonitrile (158 mL) were placed in a reaction vessel, and a 5N aqueous sodium hydroxide solution (35 mL) was added thereto. A solution prepared by diluting 3-chloropropionyl chloride (6.27 g) with acetonitrile (50 mL) was added over a period of 10 minutes. After completion of the dropwise addition, the mixture was stirred at 30° C. for 30 minutes. The reaction solution was partially taken out and measured by HPLC (condition 3). The peak area of compound B was confirmed to be less than 0.1% of the total peak area. At this stage, the diamide compound and the 3CP diamide compound were not detected in HPLC. Thereafter, a 5N aqueous sodium hydroxide solution (25 mL) was further added, and the mixture was stirred at 30° C. for 4 hours. The reaction solution was partially taken out and measured by HPLC (condition 3). The peak area of the A-1-3CP compound was confirmed to be less than 0.1% of the total peak area. After completion of the reaction, water (550 mL) was added over a period of 2 hours. After completion of the dropwise addition, the internal temperature was adjusted to 25° C., and the mixture was stirred for 1.5 hours. The insoluble matter was collected by filtration and washed with water (125 mL), followed by drying the washed matter at 60° C. under reduced pressure, thereby obtaining the Futibatinib (16.02 g, yield 85.3%).
