Potassium Carbonate → tert-Butyl 3-ethynylpiperidine-1-carboxylate

Participants

Reaction Steps

A solution of 1-BOC-3-formylpiperidine (1.46 g, 6.85 mmol) and (diazomethyl) phosphonic acid dimethyl ester (1.79 g, 11.94 mmol) in 50 mL methanol was stirred at ice-bath for 10 min, K2CO3 (1.96 g, 14.2 mmol) was added to the above mixture and stirred at ice-bath for 2 hrs, then stirred at rt overnight. The mixture was evaporated in vacuo, to the residue was added EtOAc and water, the organic layer was separated and water layer was extracted with EtOAc (100 mL×3). The combined organic layers were washed with water and brine successively, dried with Na2SO4, filtered, and the filtrate was evaporated in vacuo to give 1.44 g product as colorless oil (100.0%). 1H NMR (300 MHz, CDCl3) δ: 3.90 (1 H, brs), 3.70-3.75 (1 H, m), 2.95-3.02 (2 H, m), 2.40-2.47 (1 H, m), 2.05 (1 H, d, J=2.1 Hz), 1.94-1.99 (1 H, m), 1.69-1.73 (1 H, m), 1.50-1.63 (2 H, m), 1.46 (9 H, s).

Provenance & Evidence