反应详情

温度

95 °C

A solution of 2.56 g (22.7 mmol) of glycinamide hydrochloride (purity 98%) in 200 ml of water is heated to 95° C. and the pH adjusted to 6.6 with Na2CO3 20% w/v in water. Then ethyl 4-oxobutanoate (purity 97%) (7.60 g, 56.6 mmol) are added dropwise during four hours maintaining the temperature at 95° C. and the pH at 6.6 by automated addition (pHstat) of Na2CO3 20% w/v in water. The solution is stirred at 95° C. for 1.5 hours and then concentrated to a small volume under vacuum. The obtained suspension is treated with 50 ml of isopropanol and the solvent is evaporated at atmospheric pressure. This operation is repeated once again. The residue is diluted with 50 ml of isopropanol and the resulting suspension heated to 60° C. and then filtered. The filtrate is concentrated to about 15 ml, cooled to room temperature and stirring continued for about 2 hours. The white precipitate is collected by suction filtration, washed with 4 ml of isopropanol and dried under vacuum at 60° C. for 12 hours, resulting in 1.8 g of crude dimiracetam (12.8 mmol, 55.5%). Recrystallization from isopropanol (10 volumes) affords 1.6 g (50%) of pure dimiracetam (>99.5% as determined from area % HPLC). Melting point: 154° C.

1. concentrationconcentrated to a small volume under vacuum
2. additionThe obtained suspension is treated with 50 ml of isopropanol
3. customthe solvent is evaporated at atmospheric pressure
4. additionThe residue is diluted with 50 ml of isopropanol
5. temperaturethe resulting suspension heated to 60° C.
6. filtrationfiltered
7. concentrationThe filtrate is concentrated to about 15 ml
8. temperaturecooled to room temperature
9. stirringstirring
10. waitcontinued for about 2 hours
11. filtrationThe white precipitate is collected by suction filtration
12. washwashed with 4 ml of isopropanol
13. customdried under vacuum at 60° C. for 12 hours