| 摘要 |
Gamma-methyl glutamate hydrochloride is prepared by preparing at a temperature not exceeding 10 DEG C. a substantially anhydrous solution containing methanol, glutamic acid hydrochloride and hydrogen chloride having a molar ratio of methanol to glutamic acid hydrochloride of at least 15:1 and a molar ratio of hydrogen chloride to glutamic acid hydrochloride of at least 1:4, maintaining said solution at a temperature in the range - 10 DEG to + 10 DEG C. until the concentration of glutamic acid hydrochloride in the solution falls to 3% or less of its initial value, and treating the solution to terminate the reaction of the methanol with the glutamic acid hydrochloride. The reaction may be terminated by cooling to below -20 DEG C., followed by vacuum or spray-drying to recover gamma-methyl glutamate hydrochloride, or may be terminated by neutralization with an alkali, when free gamma-methyl glutamate is recovered as the product. Subsequent treatment with ethylene dichloride and/or acetone removes dimethyl glutamate impurites. |
