Sodium Bicarbonate → (S)-benzyl 3-(tert-butoxycarbonylamino)-5-ethylidenepiperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a suspension of ethyltriphenylphosphonium bromide (11 eq) in 14 mL of THF was added potassium tert-butoxide (10 eq) at room temperature. The reaction mixture was stirred at that temperature for 20 minutes. Then the reaction was cooled to 0° C., and (S)-benzyl 3-(tert-butoxycarbonylamino)-5-oxopiperidine-1-carboxylate (1 eq) in 7 mL of THF was added to the reaction mixture. The reaction was allowed to warm up room temperature. After being stirred for 40 minutes, the reaction mixture was poured into aq. sodium bicarbonate and extracted with ethyl acetate. The organic layer was separated and washed with brine, then dried over anhydrous MgSO4, filtered, and concentrated in vacuo. The crude residue was purified by flash chromatography (EtOAc:hexanes=2:1) to yield (S)-benzyl 3-(tert-butoxycarbonylamino)-5-ethylidenepiperidine-1-carboxylate. LC/MS (m/z): 261.2 (MH+-100), Rt:1.12 min. HPLC: Rt:4.31 min.

Provenance & Evidence