Ethyl isonipecotate (50 g, 0.31 mol) was dissolved in toluene (150 mL) in a round
bottom flask, charged with potassium carbonate (60 g, 0.43
mol) and stirred for 15 min. Benzyl chloride (42 g, 0.31 mol)
was charged and the reaction mass was refluxed for 4 h at
100 °C. Upon completion of the reaction as marked by TLC
(hexane:ethyl acetate; 2:1), the reaction mass was cooled to
room temperature and quenched with water (100 mL), stirred
and the organic phase was separated. The aqueous phase was
again extracted with toluene (100 mL). Combined organic
phase was washed twice with saturated brine solution (50 mL).
Remove toluene in vacuo to obtain Ethyl N-benzylpiperidine-4-carboxylate
( 6.97 g, 91 %) as a yellow liquid.
