2343-25-1

600 g of 2-ethynyl-4-fluoroaniline and 4 L of water were added to the reaction flask, and then 476 g of hydrochloric acid (concentration: 35%) was added, and thereaction was carried out at 50 ??C for 36 hours.After the reaction, the temperature is lowered to 20-25 ??C, the reaction solution is adjusted to pH 8-9 with 50% sodium hydroxide solution, thetemperature is controlled to not exceed 30 ??C during pH adjustment, and the filter cake is washed with 1 L of water and decompressed at 50 ??C. After drying for 12 h, 622 g of pale yellow solid was obtained, yield91.4%.HPLC purity was 99.2%.

[1] Patent: WO2013/50527, 2013, A1. Location in patent: Page/Page column 45; 46