反应详情

To a solution of 2-chloro-benzooxazole-7-carboxylic acid methyl ester (0.43 g, 2.05 mmol, 1.0 equiv) in acetonitrile (30 mL) was added ethyl 4-amino-1-piperidine carboxylate (0.64 g, 3.08 mmol, 1.5 equiv) and the reaction mixture heated to reflux for 30 min. The solvent was removed under reduced pressure and the crude material purified with column chromatography on silica eluting with dichloromethane/methanol (4:1) to afforded 0.68 g (95%) of the title compound. 1H NMR (300 MHz, DMSO): δ 1.19 (t, J=7.0 Hz, 3H), 1.38-1.51 (m, 2H), 1.95-2.00 (m, 2H), 2.96-3.03 (m, 2H), 3.78-3.81 (m, 1H), 3.89 (s, 3H), 3.82-3.96 (m, 2H), 4.04 (q, J=7.0 Hz, 2H), 7.23 (t, J=7.9 Hz, 1H), 7.50 (dd, J=7.9 Hz, J=1.9 Hz, 2H), 8.34 (d, J=7.3 Hz, 2H). 13C NMR (75 MHz, DMSO): δ 14.54, 31.01, 42.04, 49.71, 52.05, 60.63, 112.36, 119.98, 121.27, 123.51, 144.77, 147.00, 154.57, 162.13, 164.17. MS (ISP): 347.9 [M+H]+.

1. temperaturethe reaction mixture heated
2. temperatureto reflux for 30 min
3. customThe solvent was removed under reduced pressure
4. customthe crude material purified with column chromatography on silica eluting with dichloromethane/methanol (4:1)