Ajinomoto Co., Ltd.

Tokyo Shibaura Denki Kabushiki Kaisha

Toyoto Hijiya

Tadashi Takemoto

Toshihide Yukawa

Chiaki Mochizuki

Teruo Yonekawa

Tetsuo Yamatani

Kenichi Mori

Toru Ikeda

Hideo Takeda

Kiichiro Tanaka

Naoko Sugiyama

Koji Shibuya

Kunisuke Izawa

Hiroshi Takeuchi

Kazutaka Nagashima

Satoji Takahashi

Takayoshi Torii

Ryoichiro Nakamura

Eriko Ono

Kunio Hisamitsu

Hajime Kamada

Yusuki Amino

The present invention provides a novel crystal of alanine alkyl ester sulfonate having low hygroscopicity and low corrosiveness, which can be produced industrially economically. The present invention provides crystals of alanine alkyl ester sulfonates represented by formula (1): wherein Ris a methyl group or an ethyl group, provided that when Ris a methyl group, Ris an ethylphenyl group or a dimethylphenyl group; and when Ris an ethyl group, Ris a methyl group, a phenyl group, a chlorophenyl group, an ethylphenyl group, or a dimethylphenyl group.

Crystal of amino acid ester salt and process for producing the same

An N-9-position alkylated form is selectively precipitated by subjecting a mixture containing the N-9-position alkylated form and an N-7-position alkylated form of 2-amino-6-halopurine to a crystallization step using a mixed solvent of an organic solvent and water. Then, this N-9-position alkylated form is reduced to give famciclovir. By this method of the present invention, famciclovir known as an antiviral agent, and an intermediate compound therefor can be efficiently produced.

Production method of famciclovir and production and crystallization method of intermediate therefor

Spherical aggregate crystals of a phosphoric acid/lysine/magnesium composite salt represented by formula (1):

Aggregate crystals of phosphoric acid/lysine/magnesium composite salt

A process for optical resolution of a racemic substituted benzylamine is provided that involves reacting the racemic substituted benzylamine in a solvent with an optically active N-acyl-phenylalanine, -aspartic acid, or -glutamic acid, and separating the diastereomers formed by making use of the difference in the mutual solubilities of the two diastereomer salts which are generated therein.

Adduct salts of novel substituted benzylamines and a process for

Phosphoric acid-amino acid-polyvalent metal composite salt and ruminant

An economical process for producing .alpha.-L-aspartyldipeptide amide derivatives useful as sweeteners, by using amino protecting groups which can be removed by hydrolysis under acidic conditions, resulting in conversion of a .beta.-carboxyl acid ester to a carboxylic acid.

Process for producing .alpha.-l-aspartyldipeptide amide derivatives

L-amino acid amides are converted to the corresponding D-amino acid amides. An amide formed from an L-amino acid and an optically active (S)-.alpha.-alkylbenzylamine is subjected to dehydration condensation with an aryl aldehyde to form a Schiff's base, which is racemized at the amino acid moiety in the presence of a base to yield an N-allylidene-D-amino acid-(S)-amide. The less-soluble diastereomer N-allylidene-D-amino acid-(S)-amide is crystallized from the reaction mixture and recovered by means of solid/liquid separation. The N-allylidene form is readily hydrolyzed into the amino acid-(S)-amide and the starting aldehyde.

Method of preparing D-amino acid-N-(S)-.alpha.-alkylbenzylamide

To produce optically active .alpha.-arylalkylamine from optically impure .alpha.-arylalkylamine. Optically impure .alpha.-arylalkylamine is mixed with optically active N-acyl-aspartic acid or glutamic acid in a solvent and the resulting two types of diastereomer salts are optically resolved utilizing difference in solubility.

Addition salt of acyl-amino acid and .alpha.-aryl amine and process for

The present invention provides crystals of L-phenylalanine monomethyl sulfate which have low solubility compared to L-tyrosine and D-phenylalanine. The L-phenylalanine monomethylsulfate crystals are obtained by subjecting a solution containing monomethyl sulfuric acid and phenylalanine to crystallization. Further, the present invention also provides a process for recovering L-phenylalanine from a water layer by neutralizing the esterified reaction, extracting an ester of L-phenylalanine therefrom with an organic solvent, and recovering remaining L-phenylalanine in the water layer as L-phenylalanine monomethylsulfate. L-phenylalanine monomethyl sulfate is obtained by esterifying L-phenylalanine and methanol in the presence of sulfuric acid, neutralizing the esterified solution with a base in the presence of water, extracting the produced L-phenylalanine methyl ester from the neutralized solution with an organic solvent, and then crystallized the resultant water layer under acidic condition.

Method for recovering L-phenylalanine

The present invention provides a method of preparing L-aspartyl-D-.alpha.-aminoalkane carboxylic acid-(S)-N-.alpha.-alkylbenzylamide which is less expensive and more efficient than previous methods using N-protected-L-aspartic anhydride.

Method of preparing L-aspartyl-D-.alpha.-aminoalkane carboxylic

A process for improving the yield of crystallization of L-phenylalanine monomethyl sulfate from an aqueous solution containing L-phenylalanine and monomethyl sulfate, by adding an effective crystallization improving amount of a salt of an inorganic or organic acid with an alkali metal, an alkaline earth metal or ammonium, to the aqueous solution.

Process for crystallization of L-phenylalanine monomethyl sulfate using

Addition of a reaction mixture obtained by the mineral acid hydrolysis of at least one side flow generated from the production of .alpha.-L-aspartyl-L-phenylalanine methyl ester to a crystallization slurry containing L-phenylalanine while maintaining the pH of the slurry at 3-8 by adding aqueous alkali affords crystallized L-phenylalanine having a low water content in a high yield.

Process for recovering L-phenylalanine

Disclosed herein is a process for separating N-protected-.alpha.-L-aspartyl-L-phenylalanine, more particularly a process for selectively separating N-protected-.alpha.-L-aspartyl-L-phenylalanine from a solution of N-protected-.alpha.-L-aspartyl-L-phenylalanine containing at least N-protected-.alpha.-L-aspartyl-D-phenylalanine as impurity.

Process for separation of N-protected-.alpha.-L-aspartyl-L-phenylalanines

Tripeptide sweeteners represented by formula (I)

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Kawasaki, Japan

Toyoto Hijiya