反应详情

The title compound (0.21 g, 98%) was prepared as a white foam from (±)-1,1-dimethylethyl 4-[1-({5-[4-(methylsulfonyl)phenyl]-2-pyrazinyl}oxy)ethyl]-1-piperidinecarboxylate (Example 160, 0.22 g, 0.48 mmol) and TFA (0.37 mL) in CH2Cl2 (16 mL) then diisopropylethylamine (1.25 mL) and isopropyl chloroformate (1.0M in toluene, 0.57 mL, 0.57 mmol) in a manner similar to Example 74. The crude material was purified by chromatography on a silica gel column eluted with 50% EtOAc/hexanes to afford (±)-1-methylethyl 4-[1-({5-[4-(methylsulfonyl)phenyl]-2-pyrazinyl}oxy)ethyl]-1-piperidinecarboxylate as a white foam. 1H NMR (400 MHz, CDCl3): δ 8.53 (d, 1H, J=1.0 Hz), 8.24 (d, 1H, J=1.2 Hz), 8.10 (d, 2H, J=8.5 Hz), 8.02 (d, 2H, J=8.6 Hz), 5.15-5.05 (m, 1H), 4.89 (septet, 1H, J=6.3 Hz), 4.30-4.15 (m, 2H), 3.07 (s, 3H), 2.75-2.65 (m, 2H), 1.85-1.65 (m, 3H), 1.40-1.25 (m, 5H), 1.22 (d, 6H, J=6.3 Hz); LRMS (ESI), m/z 448 (M+H).

1. customThe crude material was purified by chromatography on a silica gel column
2. washeluted with 50% EtOAc/hexanes