反应详情

温度

25 °C

A 2-liter, three-necked, round-bottomed flask equipped with a mechanical stirrer and a reflux condenser was dried at 100° C. and cooled to 25° C. under N2. Methanol (260 mL) was added, followed by a solution of sodium methoxide in methanol (25% by weight, 670 mL, 3.10 mol). The resulting solution was cooled to 0° C. Dimethyl methoxymalonate (151 g, 0.930 mol) was added in one portion, followed by formamidine acetate (100 g, 0.96 mol). The temperature was kept below 10° C. The resulting suspension was then stirred at 0° C. for 30 min, and refluxed for 1 h. The resulting suspension was cooled to 0° C. and quenched with concentrated HCl (250 mL) over 30 min, during which time the temperature was kept below 10° C. Stirring was continued at 5° C. for 30 min. The suspension was then filtered. The filter cake was re-suspended in water (1000 mL) and refluxed until a nearly clear solution was obtained. The solution was filtered while hot. The filtrate was cooled to 0-5° C. and stirred for 1 h. The solid precipitate was collected by filtration, washed with cold methanol (500 mL), and dried in a vacuum oven at 50° C. for 1 h to give the title compound (96.2 g, 73% yield) as a white solid. Exact Mass calculated for C5H6N2O3: 142.0, LCMS m/z=143.2 (M+H+); 1H NMR (400 MHz, DMSO-d6) δ 3.63 (s, 3H), 7.81 (s, 1H), 11.75 (br s, 2H).

1. customA 2-liter, three-necked, round-bottomed flask equipped with a mechanical stirrer and a reflux condenser
2. customwas dried at 100° C.
3. additionMethanol (260 mL) was added
4. temperatureThe resulting solution was cooled to 0° C
5. customwas kept below 10° C
6. temperaturerefluxed for 1 h
7. temperatureThe resulting suspension was cooled to 0° C.
8. customquenched with concentrated HCl (250 mL) over 30 min, during which time the temperature
9. customwas kept below 10° C
10. stirringStirring
11. waitwas continued at 5° C. for 30 min
12. filtrationThe suspension was then filtered
13. temperaturerefluxed until a nearly clear solution
14. customwas obtained
15. filtrationThe solution was filtered while hot
16. temperatureThe filtrate was cooled to 0-5° C.
17. stirringstirred for 1 h
18. filtrationThe solid precipitate was collected by filtration
19. washwashed with cold methanol (500 mL)
20. customdried in a vacuum oven at 50° C. for 1 h