反应详情

温度

95 °C

Iron powder (167 g, 2990 mmol), water (60 mL), and concentrated hydrochloric acid (3 mL, ˜36 mmol) were added consecutively to a solution of 4-chloro-2-nitrobenzaldehyde (55.7 g, 300 mmol) in EtOH (600 mL). After stirred (mechanically) at 95° C. for 10 min, another aliquot of concentrated hydrochloric acid (2 mL, ˜24 mmol) was added. Stirring was continued at 95° C. for another 80 min. 1-Pyridin-2-ylethanone (33 mL, 294.1 mmol) and solid KOH (50.5 g, 900 mmol) were then added in portions with caution. The resulting mixture was stirred at 95° C. for 4 h. After cooled to rt, the reaction was diluted with dichloromethane (500 mL) and filtered through a Celite pad. The filtrate was concentrated to approximately 100 mL. The desired precipitated product was collected by filtration; 1H-NMR (CDCl3, 400 MHz) δ 7.37-7.40 (m, 1H), 7.51 (dd, J=2.0, 8.8 Hz, 1H), 7.79 (d, J=8.4 Hz, 1H), 7.89 (dt, J=1.6, 8.0 Hz, 1H), 8.19 (s, 1H), 8.26 (d, J=8.8 Hz, 1H), 8.57 (d, J=8.8 Hz, 1H), 8.64 (d, J=8.4 Hz, 1H), 8.74-8.75 (m, 1H); MS (ES+): m/z 241 (MH+, 35Cl), 243 (MH+, 37Cl); HPLC: tR=3.95 min (OpenLynx, polar—5 min).

1. stirringStirring
2. waitwas continued at 95° C. for another 80 min
3. stirringThe resulting mixture was stirred at 95° C. for 4 h
4. temperatureAfter cooled to rt
5. filtrationfiltered through a Celite pad
6. concentrationThe filtrate was concentrated to approximately 100 mL
7. customThe desired precipitated product
8. filtrationwas collected by filtration
9. customHPLC: tR=3.95 min (OpenLynx, polar—5 min)