反应详情

温度

10 °C

26.8 g (0.20 mole) of L-malic acid and 8.0 g (0.20 mole) of sodium hydroxide are dissolved in 200 ml of water. The solution (pH 4.1) is concentrated under reduced pressure to make the total weight thereof 60 g. The concentrated solution is cooled to 10° C., and the mixture obtained (i.e., the mixture of the concentrated solution and crystals precipitated) is stirred at the same temperature for 4 hours. After stirring, the mixture had a pH of 4.1. The crystalline precipitates are collected by filtration, washed with an aqueous 80% methanol solution, and dried at 35° C. in air for 16 hours. 23.2 g of monosodium L-malate dihydrate are obtained as crystals. The amounts of L-malic acid, sodium and water contained in the product are shown in Table 5. The results set forth in this table indicate that the product obtained is the pure crystals of monosodium L-malate dihydrate.

1. concentrationThe solution (pH 4.1) is concentrated under reduced pressure
2. customthe mixture obtained (i.e.
3. additionthe mixture of the concentrated solution and crystals
4. customprecipitated)
5. stirringAfter stirring
6. customThe crystalline precipitates
7. filtrationare collected by filtration
8. washwashed with an aqueous 80% methanol solution
9. customdried at 35° C. in air for 16 hours