Claims
- 1. In a method for the preparation of a sodium salt of N-(phosphonoacetyl)-L-aspartic acid by reacting L-aspartic acid, dibenzyl ester p-toluenesulfonate with triethylamine, followed by the addition of phosphonoacetyl chloride to produce the N-(phosphonoacetyl)-L-aspartic acid moiety in the form of the dibenzyl ester, wherein the carboxyl groups of the N-(phosphonoacetyl)-L-aspartic acid are esterified, adding cyclohexylamine under anhydrous conditions to produce the cyclohexylamine salt of said dibenzyl ester, reacting said cyclohexylamine salt with sodium hydroxide to produce L-aspartic acid, N-(phosphonoacetyl)-, tetrasodium salt, and reacting said tetrasodium salt with acetic acid to produce L-aspartic acid, N-(phosphonoacetyl)-, disodium salt, the improvement which comprises subjecting the obtained disodium salt to a water-ethanol washing procedure, employing 92.+-.1% by volume aqueous ethanol, said washing procedure being carried out at a temperature of from about 26.degree. to about 28.degree. C., thereby reducing impurities, including acetic acid, sodium acetate and ethanol, to an acceptable level.
Government Interests
The invention described herein was made in the course of work under a grant or award from the Department of Health, Education and Welfare.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3417098 |
Anatol |
Dec 1968 |
|
4016148 |
Ratcliffe et al. |
Apr 1977 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
1488426 |
Jun 1967 |
FRX |
Non-Patent Literature Citations (1)
Entry |
Vogel, "Practical Organic Chemistry" (1948), pp. 122-131. |