摘要:
A process for obtaining dry crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a water content of about 2 wt. % to about 6 wt. % based on the weight of the wet crystals is disclosed. This process comprises exposing wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester, having a water content not greater than 50 wt. % based on the weight of the wet crystals and obtained by the crystallization of .alpha.-L-aspartyl-L-phenylalanine methyl ester from an unagitated solution of .alpha.-L-aspartyl-L-phenylalanine methyl ester, to a flow of air having a temperature of 80.degree. C. to 200.degree. C.
摘要:
The present invention discloses a method to separate each component from a mixed solution of organic solvents obtained during the production of .alpha.-L-aspartyl-L-phenylalanine methyl ester, which is useful as a sweetener, namely, a mixed solution of acetic acid and toluene or a mixed solution of acetic acid, toluene and formic acid, recovering each component with a high recovery ratio with as small number of operations as possible. The method rationalizes the process and is highly valuable in practical use.When each component is separated and recovered from a mixed solution containing acetic acid and toluene as the main components, acetic acid and toluene are separated by azeotropic distillation using water as an azeotropic solvent, and when each component is separated and recovered from a mixed solution containing acetic acid, toluene and formic acid as the main components, (a) the mixed solution is distilled and formic acid is recovered from the top of the column and a mixed solution of acetic acid and toluene is recovered from the bottom of the column; and (b) the mixed solution obtained from the bottom is distilled by using water as an azeotropic solvent and toluene is recovered from the top of the column and acetic acid is recovered from the bottom of the column.
摘要:
Granules of .alpha.-L-aspartyl-L-phenylalanine methyl ester, containing IB crystals of the ester and having a grain size of from 100 to 1400 .mu.m have improved water solubility.
摘要:
A method for the solid-liquid separation of a suspension of .alpha.-L-aspartyl-L-phenylalanine methyl ester (.alpha.-APM) or its hydrochloride salt (.alpha.-APM.HCl), wherein an aqueous suspension of .alpha.-L-aspartyl-L-phenylalanine methyl ester or its hydrochloride salt is subjected to continuous separation by vacuum filtration.
摘要:
A crystalline L-alpha-aspartyl-L-phenyl-alanine methyl ester product is disclosed. The product is obtained by crystallizing the ester from an aqueous solution, by cooling. The initial concentration of ester in the aqueous solution used provides at least 10 grams of precipitated solid phase per liter of solution. The solution is cooled through conductive heat transfer without effecting forced flow to form a sherbet-like pseudo solid phase.
摘要:
A method for dissolving crystalline L-alpha-aspartyl-L-phenyl alanine methyl ester product is disclosed. The product is obtained by crystallizing the ester from an aqueous solution, by cooling. The initial concentration of ester in the aqueous solution used provides at least 10 grams of precipitated solid phase per liter of solution. The solution is cooled through conductive heat transfer without effecting forced flow to form a sherbet-like pseudo solid phase
摘要:
A crystalline L-.alpha.-aspartyl-L-phenylalanine methyl ester product and the process for obtaining the same are disclosed. This product is obtained by adjusting the initial concentration of L-.alpha.-aspartyl-L-phenylalanine methyl ester in an aqueous solution so that the amount of precipitated solid, formed after cooling said solution, is about 10 grams or more of precipitate per liter of solvent. The solution is then cooled through conductive heat transfer, without causing forced flow, to obtain a sherbet-like pseudo solid phase.
摘要:
A crystalline L-alpha-aspartyl-L-phenyl-alanine methyl ester product is disclosed. The product is obtained by crystallizing the ester from an aqueous solution, by cooling. The initial concentration of ester in the aqueous solution used provides at least 10 grams of precipitated solid phase per liter of solution. The solution is cooled through conductive heat transfer without effecting forced flow to form a sherbet-like pseudo solid phase.
摘要:
A method for dissolving crystalline L-alpha-aspartyl-L-phenyl-alanine methyl ester product is disclosed. The product is obtained by crystallizing the ester from an aqueous solution, by cooling. The initial concentration of ester in the aqueous solution used provides at least 10 grams of precipitated solid phase per liter of solution. The solution is cooled through conductive heat transfer without effecting forced flow to form a sherbet-like pseudo solid phase.
摘要:
A process for crystallizing L-alpha-aspartyl-L-phenylalanine methyl ester from its aqueous solution by cooling, which comprises adjusting the initial concentration of the ester so that the amount of a precipitated solid phase to be formed after cooling becomes about 10 grams or more per liter of the solvent, cooling the solution through conductive heat transfer through a cooled surface to form an apparently sherbet-like pseudosolid phase without causing forced flow by mechanical stirring or the like, and optionally further cooling the system after formation of the pseudosolid phase, is disclosed along with various apparatuses which may be used to carry out the invention.