反应详情

温度

45 °C

After all the 5-(4-methyl-piperazin-1-yl)-2-nitroaniline had disappeared from the reaction, the solution was purged with N2 for 15 minutes. Next, 440.0 g (2.25 mol) of ethyl 3-ethoxy-3-iminopropanoate hydrochloride was added as a solid. The reaction was stirred at 40-50° C. (internal temperature) until the reaction was complete. The reaction was monitored by following the disappearance of the diamino compound by HPLC. The typical reaction time was 1-2 hours. After the reaction was complete, it was cooled to room temperature and filtered through a pad of Celite filtering material. The Celite filtering material was washed with absolute EtOH (2×250 mL), and the filtrate was concentrated under reduced pressure providing a thick brown/orange oil. The resulting oil was taken up in 850 mL of a 0.37% HCl solution. Solid NaOH (25 g) was then added in one portion, and a precipitate formed. The resulting mixture was stirred for 1 hour and then filtered. The solid was washed with H2O (2×400 mL) and dried at 50° C. in a vacuum oven providing 251.7 g (74.1%) of [6-(4-methyl-piperazin-1-yl)-1H-benzoimidazol-2-yl]-acetic acid ethyl ester as a pale yellow powder.

1. customthe solution was purged with N2 for 15 minutes
2. temperatureit was cooled to room temperature
3. filtrationfiltered through a pad of Celite
4. filtrationfiltering material
5. filtrationThe Celite filtering material
6. washwas washed with absolute EtOH (2×250 mL)
7. concentrationthe filtrate was concentrated under reduced pressure
8. customproviding a thick brown/orange oil
9. customa precipitate formed
10. stirringThe resulting mixture was stirred for 1 hour
11. filtrationfiltered
12. washThe solid was washed with H2O (2×400 mL)
13. customdried at 50° C. in a vacuum oven