Hexane → Ethyl N-Boc-4-fluoropiperidine-4-carboxylate

Participants

Reaction Steps

A solution of 1-tert-butyl 4-ethyl piperidine-1,4-dicarboxylate (1.50 g, 5.81 mmol) in THF (25.0 mL) was cooled to −78° C. followed by drop wise addition of LDA (1.80 M in THF, 6.50 mL, 11.62 mmol) and the mixture stirred at the same temperature for 45 min followed by addition of N-fluorobenzenesulphonimide (3.60 g, 11.62 mmol) at −78° C. The temperature of the reaction was slowly raised to rt and left to stir for 5-6 h. The reaction was then cooled to 0° C. and quenched by drop wise addition of saturated NH4Cl solution (50 mL), extracted with EtOAc (3×100 mL) and the combined organics was washed with brine, dried (Na2SO4), filtered and concentrated under reduced pressure. The crude residue was purified over 100-200 M silica-gel using 2% EtOAc:hexane to obtain the product as an orange viscous liquid (1.0 g, 63% yield). MS: 276.27 [M+H]+.

Provenance & Evidence