反应详情

温度

0 °C

Then, 19 g (87.4 mmol) of ethyl 5-amino-2-chloro-4-fluorobenzoate was dissolved in 120 ml of hydrochloric acid, followed by cooling to 0° C., to which a solution of 6.3 g (91.7 mmol) of sodium nitrite dissolved in 10 ml of water was added dropwise at 10° C. or lower. The mixture was stirred at 0° C. for 30 minutes and then cooled to −30° C., into which a solution of 58 g (0.31 mol) of anhydrous tin (II) chloride dissolved in 40 ml of hydrochloric acid was poured, followed by further stirring at 0° C. for 3 hours. The precipitated crystals were collected by filtration and then dried, which afforded 13.6 g (50.7 mmol) of crude ethyl 2-chloro-4-fluoro-5-hydrazinobenzoate hydrochloride.

1. additionwas added dropwise at 10° C.
2. additionwas poured
3. stirringby further stirring at 0° C. for 3 hours
4. filtrationThe precipitated crystals were collected by filtration
5. customdried