845909-49-1

Ethyl 4-fluoropiperidine-4-carboxylate, HCl

General procedure for the synthesis of ethyl 4-fluoro-4-piperidinecarboxylate hydrochloride from ethyl N-Boc-4-fluoro-4-piperidinecarboxylate: To a solution of tert-butyl 4-chloro-4-tert-butyl-4-fluoro-piperidine-1,4-dicarboxylate (15 g, 54.48 mmol, 1.00 eq.) in methylene chloride (150 mL), a solution of 4 M hydrogen chloride in dioxane (100 mL) was added. The reaction mixture was stirred at 25 °C overnight. Upon completion of the reaction, the mixture was concentrated under reduced pressure to afford 11 g (95% yield) of ethyl 4-fluoropiperidine-4-carboxylate hydrochloride as a white solid.

[1] Patent: US2018/79742, 2018, A1. Location in patent: Paragraph 0328; 0329
[2] Patent: US2012/88750, 2012, A1. Location in patent: Page/Page column 34; 35
[3] Patent: US2018/258076, 2018, A1. Location in patent: Paragraph 0506