Acetic Acid → Benzyl 4-(1-(tert-butoxycarbonyl)piperidin-4-yl)piperazine-1-carboxylate

Participants

Reaction Steps

Combined 1-boc-4-piperidone (10.0 g, 50.2 mmol), benzyl 1-piperazine-carboxylate (19.3 mL, 100.4 mmol), HOAc (4.3 mL, 75.3 mmol) and TEA (7.0 mL, 50.2 mmol) in DCE (150 mL) were stirred at rt. Sodium triacetoxyborohydride was added (16.0 g, 75.3 mmol). The reaction was stirred for 3 h at which point TLC shows starting material is consumed. The reaction was quenched with NaHCO3 and extracted with DCM (3×). Combined organics were dried over MgSO4, filtered and concentrated in vacuo. Diluted crude material with DCM and adsorbed onto a prepacked silica gel solid loading cartridge and purified by column chromatography to give title compound of step A (yield not obtained). 1H NMR (400 MHz, DMSO-d6) δ ppm 7.04-7.52 (m, 5H), 5.02 (s, 2H), 3.74-4.05 (m, 2H), 3.06-3.49 (m, 4H), 2.63 (br. s., 2H), 2.22-2.50 (m, 5H), 1.64 (d, J=12.1 Hz, 2H), 1.07-1.27 (m, 2H), 1.34 (s, 9H).

Provenance & Evidence