- STORAGE-STABLE FORM OF 3-METHYLTHIOPROPIONALDEHYDE
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A chemical compound of formula (I), and specific compositions including 3-methylthiopropionaldehyde, 3-methylthiopropane-1,1-diol, a compound of formula I and water, and processes for producing same and also the use of same may be used for the production of 2-hydroxy-4-(methylthio)butyronitrile, methionine hydantoin, methionine. Protected forms may be used for the storage and/or transport of 3-methylthiopropionaldehyde.
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Paragraph 0058-0059
(2021/11/13)
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- SALT-FREE PRODUCTION OF METHIONINE FROM METHIONINE NITRILE
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The invention refers to the use of a particulate catalyst containing 60.0 to 99.5 wt.% ZrO2 stabilised with an oxide of the element Hf and at least one oxide of the element M, wherein M = Ce, Si, Ti, or Y, for the hydrolysis reaction of methionine amide to methionine, wherein the median particle size x50 of the particulate catalyst is in the range of from 0.8 to 9.0 mm, preferably of from 1.0 to 7.0 mm. The invention also refers to a process for preparing methionine comprising a step of contacting a solution or suspension comprising methionine amide and water with said particulate catalyst to provide a reaction mixture comprising methionine and/or its ammonium salt from which methionine can be isolated.
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Page/Page column 14
(2020/08/22)
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- PROCESS FOR THE PREPARATION OF METHIONINE
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The present invention relates to a process for the preparation of methionine comprising the step of contacting a solution or suspension comprising 2-amino-4-(methylthio)butanenitrile and/or 2-amino- 4-(methylthio)butaneamide with water in the presence of a catalyst to give a methionine comprising mixture, wherein the catalyst comprises CeO2 comprising particles, wherein the CeO2 comprising particles have a BET surface area of from 175 to 300 +/- 10% m2/g measured according to DIN ISO 9277-5 (2003), a mean maximum Feret diameter xFmax, mean of from 3 +/- 10% to 40 +/- 10% nm and a mean minimum Feret diameter xFmin, mean of from 2 +/- 10% to 30 +/- 10% nm, both measured according to DIN ISO 9276-6 (2012).
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Page/Page column 19
(2020/12/30)
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- METHOD FOR PRODUCING alpha-AMINO ACID
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The present invention relates to a method for producing a specified α-amino acid, the method including allowing a specified α-amino acid amide and water to react with each other in the presence of a zirconium compound which contains zirconium and at least one metal element selected from the group consisting of lithium, nickel, copper, zinc, cesium, barium, hafnium, tantalum, cerium, and dysprosium.
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Paragraph 0147-0149
(2019/06/24)
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- Carbohydrates as efficient catalysts for the hydration of α-amino nitriles
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Directed hydration of α-amino nitriles was achieved under mild conditions using simple carbohydrates as catalysts exploiting temporary intramolecularity. A broadly applicable procedure using both formaldehyde and NaOH as catalysts efficiently hydrated a variety of primary and secondary susbtrates, and allowed the hydration of enantiopure substrates to proceed without racemization. This work also provides a rare comparison of the catalytic activity of carbohydrates, and shows that the simple aldehydes at the basis of chemical evolution are efficient organocatalysts mimicking the function of hydratase enzymes. Optimal catalytic efficiency was observed with destabilized aldehydes, and with difficult substrates only simple carbohydrates such as formaldehyde and glycolaldehyde proved reliable.
- Chitale, Sampada,Derasp, Joshua S.,Hussain, Bashir,Tanveer, Kashif,Beauchemin, André M.
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supporting information
p. 13147 - 13150
(2016/11/09)
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- Process for the preparation of alpha-amino acids by hydrolysis of hydantoins at elevated pressure and elevated temperature
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A process for the preparation of α-amino acids by hydrolysis of hydantoins in the presence of water and at least one metallic oxide under conditions such that all the starting materials are completely dissolved in the water as a result of high pressure and high temperature and only one further phase is present in the reactor in addition to the metallic oxide phase.
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- α-Aminonitrile hydration in the presence of hydrogen peroxide in aqueous basic medium
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α-Aminonitriles are hydrated into α-aminoamides in the presence of hydrogen peroxide in sodic or ammoniacal basic medium. While the hydration mechanism is close to the mechanism described previously in the case of aromatic nitrites, we showed that, in weakly basic conditions, the amine function of α-aminonitrile is competitively oxidized via a peroxyimidic acid by an intramolecular process. In the case of 2-aminopropanenitrile, this reaction leads to pyruvamide oxime. Furthermore, the study of structurereactivity relationships in the hydration of aliphatic and aromatic monofunctional nitriles and α-aminonitriles showed that the reactivity of the substrates towards hydroperoxide onion, which mostly depends on inductive effects of the substituents, is sufficiently enhanced to allow hydration of tertiary α-aminonitriles with low steric hindrance and regioselective hydration of dissymmetric α-aminodinitriles. Eisevier,.
- Taillades, Jacques
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- Process for the chemical catalytic hydrolysis of an α-aminonitrile or of one of the salts thereof
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A process for the chemical catalytic hydrolysis of an α-aminonitrile or of one of the salts thereof, characterized in that an aqueous solution containing at least one carbonyl derivative is reacted with the said α-amine nitrile or with one of the salts thereof in the presence of hydroxide ions.
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