Methanol → N-Cbz-4,4'-bipiperidine

Participants

Reaction Steps

4,4′-Bipiperidine dihydrochloride (2.95 g) was mixed with MeOH (25 ml), and a mixture of benzyl chloroformate (2.2 g) and toluene (5 ml) was added dropwise thereto over 1 hour while keeping the solution neutral by adding a 6M aqueous NaOH solution at the same time. The reaction mixture was stirred at room temperature for 30 minutes and then concentrated under reduced pressure. CHCl3, and a saturated aqueous sodium hydrogen carbonate solution were added to the reaction mixture. The organic layer was dried over Na2SO4 and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (CHCl3/MeOH) to obtain benzyl 4,4′-bipiperidine-1-carboxylate (1.5 g).

Provenance & Evidence