反应详情

温度

15 °C

Ethyl malonamate (34.7 g, 0.26 mole) and methanol (100 ml) were placed in a flash equipped with a dropping funnel, a stirrer, and a soda lime trap (to exclude CO2). The flask was cooled to about 15° C. in an ice-water bath. Freshly prepared biguanide (26.3 g, 0.26 mole, in 250 ml methanol) was added, with stirring, over 35 min at 15°-20° C. A white precipitate began to form within 8-9 min. The mixture was allowed to stir overnight at room temperature. It was then cooled to 15° C., and the white precipitate was filtered, washed with cold water to remove sodium sulfate, and finally washed with cold methanol. A crude yield of 32.7 g (76%) was obtained. A pure sample recrystallized from water had a mp of 295°-96° C. (dec.) when placed in a preheated bath at 295° C. Anal. calcd. for C5H8N6O: C, 36.59; H, 4.91; N, 48.76. Found: C, 36.73; H, 5.08; N, 48.51.

1. customto form within 8-9 min
2. stirringto stir overnight at room temperature
3. temperatureIt was then cooled to 15° C.
4. filtrationthe white precipitate was filtered
5. washwashed with cold water
6. customto remove sodium sulfate
7. washfinally washed with cold methanol
8. customA crude yield of 32.7 g (76%) was obtained
9. customA pure sample recrystallized from water
10. customplaced in a preheated bath at 295° C