反应详情

Freshly prepared biguanide (6.1 g, 0.06 mole) in methanol (700 ml) was placed in a flask equipped with a stirrer and a soda lime trap to exclude CO2. IV (25.0 g, 0.06 mole) was added all at once through a powder funnel. After the solution was stirred for 10 min at room temperature, a white precipitate began to form. After being stirred for 7.5 h, the mixture was allowed to stand overnight. The crystals were filtered and washed with fresh methanol. They were then slurried with water (250 ml), filtered again, and washed with methanol. A crude yield of 21.9 g (81%) was obtained. It was recrystallized by dissolving 21.8 g in 80 ml of hot DMF (125° C.) and then adding 9 ml of water dropwise. When the solution cooled, white crystals separated. A second crop of crystals was obtained from the filtrate. The total recovery was 15.5 g, a yield of 57% based on the theoretical yield of 27.2 g. An analytical sample with mp of 250°-51° C. was obtained by recrystallizing again from hot DMF and finally washing with cold methanol. Anal. calcd. for C10H9Br3N6 : C, 26.52; H, 2.00; Br, 52.93; N, 18.55. Found: C, 26.52; H, 2.02; Br, 52.71; N, 18.59.

1. customequipped with a stirrer and a soda lime trap
2. customto form
3. stirringAfter being stirred for 7.5 h
4. waitto stand overnight
5. filtrationThe crystals were filtered
6. washwashed with fresh methanol
7. filtrationfiltered again
8. washwashed with methanol
9. customA crude yield of 21.9 g (81%) was obtained
10. customIt was recrystallized
11. dissolutionby dissolving 21.8 g in 80 ml of hot DMF (125° C.)
12. additionadding 9 ml of water dropwise
13. temperatureWhen the solution cooled
14. customwhite crystals separated
15. customA second crop of crystals was obtained from the filtrate
16. customAn analytical sample with mp of 250°-51° C. was obtained
17. customby recrystallizing again from hot DMF
18. washfinally washing with cold methanol