反应详情

A mixture of tert-butyl 4-(3-hydroxybenzylidene)piperidine-1-carboxylate (0.300 g, Example 57, Step 3), 2-bromopyridine (0.253 mL, 1.50 equiv), cesium carbonate (1.13 g, 2.01 equiv), and tetrakis(acetonitrile)copper(I) hexafluorophosphate (0.048 g, 0.075 equiv) in toluene (9 mL, 0.2 M) was heated to reflux for 12 hours. Additional tetrakis(acetonitrile)copper(I) hexafluorophosphate (0.02 g) and 2-bromopyridine (0.1 mL) were added, and the reaction was heated an additional 6 hours. After cooling to room temperature, the reaction was filtered through Celite, washing the Celite with dichloromethane. The filtrate was concentrated and purified on 60 g silica gel using a gradient eluent consisting of 0-10% ethyl acetate/dichloromethane over 60 minutes to give the title compound as a white solid. 0.483 g, 76% yield. 1H NMR (400 MHz, CDCl3) δ ppm 1.45 (9H, s), 2.29 (2H, br. S.), 2.45 (2H, t, J=5.5 Hz), 3.37 (2H, t, J=5.4 Hz), 3.47 (2H, t, J=5.7 Hz), 6.32 (1H, s), 6.76-7.13 (5H, m), 7.32 (1H, t, J=7.7 Hz), 7.67 (1H, t, J=6.5 Hz), 8.18 (1H, br. s.).

1. temperaturewas heated
2. temperatureto reflux for 12 hours
3. temperaturethe reaction was heated an additional 6 hours
4. filtrationthe reaction was filtered through Celite
5. washwashing the Celite with dichloromethane
6. concentrationThe filtrate was concentrated
7. custompurified on 60 g silica gel using a gradient eluent