Citric Acid → Benzyl 4-formylpiperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

N-Methyl-N-methoxy 1-benzyloxycarbonylpiperidin-4-carboxamide (79.9 g, 261 mmol) was azeotroped with toluene (2×200 mL) to remove any water and dissolved in THF (700 mL). The solution was cooled to −60° C., before dropwise addition of a solution of lithium aluminum hydride in TBF (1 M, 100 mL, 100 mmol). The temperature of the reaction mixture was allowed to rise slowly to −30° C. over approx. 1 h. The mixture was transferred by cannula into a rapidly stirred mixture of ethyl acetate (200 mL) and 10% aqueous citric acid (500 mL), cooled to 0° C. After addition was complete, ether (500 mL) was added and the phases separated. The organic layer was washed with 1M HCl, water, saturated sodium bicarbonate solution and brine. After drying over anhydrous sodium sulfate, the solvent was evaporated in vacuo to afford the crude product, used without further purification (59 g).

Provenance & Evidence