Benzylamine → tert-Butyl 4-(benzylamino)-3,3-difluoropiperidine-1-carboxylate

To a solution of 1-tert-butyloxycarbonyl-3,3-difluoro-4-oxopiperidine (Synthonix, 0.100 g, 0.426 mmol, 1.0 eq) in dichloromethane (1.5 mL) was added benzylamine (0.070 mL, 0.638 mmol, 1.5 eq) followed by sodium triacetoxyborohydride (0.180 g, 0.851 mmol, 2.0 eq). The reaction was stirred at room temperature for 16 hours before adding Rochelle's salt (2 mL) and stirring for 1 hour. The reaction mixture was partitioned between NaHCO3 (50 mL) and CH2Cl2 (50 mL). The aqueous phase was extracted with CH2Cl2 (2×50 mL). The combined organics were washed with brine (50 mL), dried (Na2SO4) and concentrated under reduced pressure. MPLC (30→70% EtOAc-hexane) yielded the title compound (0.045 g, 32%) as a colourless oil; 1H nmr (CDCl3) δ 7.33 (4H, m, 4H of C6H5), 7.27 (1H, m, 1H of C6H5), 4.02 (1H, m), 3.92 (2H, s, CH2C6H5), 3.76 (1H, m), 3.32 (1H, ddd, J 21.5, 14.0, 4.5 Hz), 3.11 (1H, m), 2.97 (1H, m), 1.90 (1H, m), 1.67-1.59 (1H, m), 1.46 (9H, s, C(CH3)3); 19F nmr (CDCl3) δ −109.0 (dd, J 243.0, 115.5 Hz), −119.5 (d, J 251.0 Hz); m/z: 327 [M+H]+.

1. stirringstirring for 1 hour
2. customThe reaction mixture was partitioned between NaHCO3 (50 mL) and CH2Cl2 (50 mL)
3. extractionThe aqueous phase was extracted with CH2Cl2 (2×50 mL)
4. washThe combined organics were washed with brine (50 mL)
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated under reduced pressure

ORD record

ord-0f8c86515221457e9262098db43b3201

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266856B2