tert-Butyl piperazine-1-carboxylate → HCID 89650458, compound

Participants

Reaction Steps

A mixture of 2-bromo-5-fluoro-benzaldehyde (3.00 g, 14.8 mmol), piperazine-1-carboxylic acid tert-butyl ester (2.75 g, 14.8 mmol) and sodium triacetoxyborohydride (4.38 g, 20.7 mmol) was prepared in DCE (80 mL) and stirred at RT for 3 hours. The reaction mixture was diluted with DCM (100 mL), and then washed with a mixture of saturated aqueous solution of Na2CO3 (100 mL) and water (50 mL). The aqueous layer was extracted with DCM (100 mL). The organic layers were combined, dried (Na2SO4) and concentrated under vacuum. After purification by filtration through a silica pad (EtOAc), the title compound was obtained as a white powder (5.12 g, 93%). 1H NMR (300 MHz, CDCl3) δ 7.48 (dd, J=8.8, 5.3 Hz, 1H), 7.26 (dd, J=9.6, 3.1 Hz, 1H), 6.85 (ddd, J=8.8, 7.8, 3.1 Hz, 1H), 3.56 (s, 2H), 3.49-3.42 (m, 4H), 2.50-2.42 (m, 4H), 1.46 (s, 9H). HPLC (max plot) 94.1%; Rt 2.73 min. UPLC/MS: (MS+) 373.1 and 375.1 ([M+H]+).

Provenance & Evidence