反应详情

To (R)-tert-butyl 2-(2,5-difluorophenyl)pyrrolidine-1-carboxylate (23.9 g, 84.4 mmol) was added 4N HCl in dioxane (56.2 mL). After stirring at ambient temperature for 2 hours, ether (200 mL) was added and the mixture was stirred for 10 minutes. The resulting slurry was filtered, yielding the title compound hydrochloride salt as a white solid (17.2 g). To obtain the free base, the HCl salt product was dispersed in a mixture of EtOAc (200 mL) and NaOH solution (100 mL, 2 N aq.) The layers were separated and the aqueous layer was extracted with EtOAc. The combined organic extracts were filtered and concentrated to give the desired product as a liquid (13.2 g, 85% yield).

1. stirringthe mixture was stirred for 10 minutes
2. filtrationThe resulting slurry was filtered