Diethyl Ether → tert-Butyl 4-(hydrazinecarbonyl)piperidine-1-carboxylate

Participants

Reaction Steps

Carbonyl diimidazole (3.57 g, 22 mmol) was added to a solution of 1-(tert-butoxycarbonyl)-piperidine-4-carboxylic acid (4.59 g, 20 mmol) in methylene chloride (50 mL) and stirred for two hours until gas evolution ceased. Then hydrazine (0.8 mL, ˜26 mmol) was added to the reaction and the reaction was stirred at room temperature for another two hours. The reaction was diluted with more methylene chloride and washed with sat'd aqueous NaHCO3. The organic layer was dried over anhydrous Na2SO4, filtered and the solvent evaporated to give a viscous residue. Trituration with diethyl ether afforded tert-butyl 4-(hydrazinocarbonyl)-piperidine-1-carboxylate as an off-white solid. NMR (CDCl3): δ6.77 (1H, br s), 4.15 (2H, br s), 3.90 (2H, v br s), 2.75 (2H, b s), 2.22 (1H, m), 1.78 (2H, br d, J=11.9 Hz), 1.66 (2H, br q, J=12.2 Hz, J=27.5 Hz), 1.47 (9H, s).

Provenance & Evidence