3198-47-8Relevant articles and documents
SALT-FREE PRODUCTION OF METHIONINE FROM METHIONINE NITRILE
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Page/Page column 14, (2020/08/22)
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.
PROCESS FOR THE PREPARATION OF METHIONINE
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Page/Page column 19, (2020/12/30)
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).
METHOD FOR PRODUCING METHIONINE
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Page/Page column 15, (2020/07/07)
The present invention pertains to a method for producing methionine or salts or derivatives thereof from hydrogen cyanide (HCN), the method comprising a step of producing 2-hydroxy-4-(methylthio)butyronitrile (MMP-CN), or a crude product mixture comprising MMP-CN, by contacting a hydrogen cyanide (HCN) process gas mixture prepared according to the Andrussow process from methane, ammonia and oxygen, with 3-methylmercaptopropionaldehyde (MMP), wherein the HCN process gas mixture is obtained from the crude HCN process gas mixture by adjusting the amount of ammonia to between 20 % (v/v) and 60% (v/v) of the amount of the ammonia in the crude HCN process gas mixture.
Titanium-Catalyzed Cyano-Borrowing Reaction for the Direct Amination of Cyanohydrins with Ammonia
Li, Qing-Hua,Li, Zhao-Feng,Tao, Jing,Li, Wan-Fang,Ren, Li-Qing,Li, Qian,Peng, Yun-Gui,Liu, Tang-Lin
supporting information, p. 8429 - 8433 (2019/10/14)
α-Aminonitrile was an important building block in natural products and key intermedia in organic chemistry. Herein, the direct amination of cyanohydrins with the partner of ammonia to synthesis N-unprotected α-aminonitriles is developed. The reaction proceeds via titanium-catalyzed cyano-borrowing reaction, which features high atom economy and simple operation. A broad range of ketone or aldehyde cyanohydrins was tolerated with ammonia, and the N-unprotected α-aminonitriles were synthesis with moderate to high yields under mild reaction conditions.
METHOD FOR PRODUCING alpha-AMINO ACID
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Paragraph 0144-0146, (2019/06/24)
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.
Clean production method of methionine
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Paragraph 0039; 0043; 0048; 0053; 0058; 0063; 0067; 0071; 00, (2017/08/25)
The present invention belongs to the technical field of organic compound production, separation and purification, and particularly relates to a clean production method of methionine. According to the method, 2-amino-4-methylthiobutyronitrile is subjected to hydrolysis by using calcium hydroxide and/or barium hydroxide to prepare methionine calcium/barium, the calcium/barium salt of the byproduct 2,2'-bis-(2-methylthioethyl)iminodiacetic acid is insoluble in water so as to easily separate and purify the methionine calcium/barium and the insoluble byproduct, then the methionine calcium/barium aqueous solution is neutralized by using carbon dioxide to produce the insoluble calcium carbonate/barium and other insoluble precipitates at a high temperature so as to achieve the methionine separation purpose, and the calcium carbonate/barium salt is subjected to calcination to decompose into the carbon dioxide and the oxides, wherein the carbon dioxide and the oxides can be recycled. Compared with the method in the prior art, the method of the present invention has characteristics of low methionine loss rate, high product purity, simple operation, low cost, no low-value inorganic salt production, no emission of a lot of acidic and odor wastewater, and green environmental protection.
METHOD FOR PRODUCING METHIONINE
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Paragraph 0034, (2017/10/10)
A method for producing methionine involves contacting 2-amino-4-(methylthio)butanenitrile with water in the presence of an oxide catalyst containing cerium. The 2-amino-4-(methylthio)butanenitrile may be 2-amino-4-(methylthio)butanenitrile, produced by contacting 2-hydroxy-4-(methylthio)butanenitrile with ammonia water or 2-amino-4-(methylthio)butanenitrile, produced by contacting 3-(methylthio)propionaldehyde with hydrocyanic acid and ammonia water.
Prebiotic selection and assembly of proteinogenic amino acids and natural nucleotides from complex mixtures
Islam, Saidul,Bu?ar, Dejan-Kre?imir,Powner, Matthew W.
, p. 584 - 589 (2017/05/31)
A central problem for the prebiotic synthesis of biological amino acids and nucleotides is to avoid the concomitant synthesis of undesired or irrelevant by-products. Additionally, multistep pathways require mechanisms that enable the sequential addition of reactants and purification of intermediates that are consistent with reasonable geochemical scenarios. Here, we show that 2-aminothiazole reacts selectively with two- and three-carbon sugars (glycolaldehyde and glyceraldehyde, respectively), which results in their accumulation and purification as stable crystalline aminals. This permits ribonucleotide synthesis, even from complex sugar mixtures. Remarkably, aminal formation also overcomes the thermodynamically favoured isomerization of glyceraldehyde into dihydroxyacetone because only the aminal of glyceraldehyde separates from the equilibrating mixture. Finally, we show that aminal formation provides a novel pathway to amino acids that avoids the synthesis of the non-proteinogenic α,α-disubstituted analogues. The common physicochemical mechanism that controls the proteinogenic amino acid and ribonucleotide assembly from prebiotic mixtures suggests that these essential classes of metabolite had a unified chemical origin.
Prebiotic synthesis of aminooxazoline-5′-phosphates in water by oxidative phosphorylation
Fernández-García,Grefenstette,Powner
supporting information, p. 4919 - 4921 (2017/07/11)
RNA is essential to all life on Earth and is the leading candidate for the first biopolymer of life. Aminooxazolines have recently emerged as key prebiotic ribonucleotide precursors, and here we develop a novel strategy for aminooxazoline-5′-phosphate synthesis in water from prebiotic feedstocks. Oxidation of acrolein delivers glycidaldehyde (90%), which directs a regioselective phosphorylation in water and specifically affords 5′-phosphorylated nucleotide precursors in upto 36% yield. We also demonstrated a generational link between proteinogenic amino acids (Met, Glu, Gln) and nucleotide synthesis.
Inexpensive high-purity D, method for the preparation of L-methionine
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Paragraph 0049; 0051, (2017/02/24)
The invention is directed at the field of chemical engineering and provides a cheap preparation method for high purity D,L-methionine. The preparation method comprises the following steps: preparing a hydrocyanic acid gas mixture by using an Andrussow process; fully reacting the hydrocyanic acid gas mixture with methylthiopropionaldehyde under the catalysis of base so as to prepare a 2-hydroxy-4-methylthiobutyronityile system; reacting the 2-hydroxy-4-methylthiobutyronityile system with ammonia under the conditions of heating and pressurization and carrying out pressure reduction and deamination so as to obtain 2-amino-4-methylthiobutyronityile; and subjecting 2-amino-4-methylthiobutyronityile to acidolysis with inorganic acid so as to obtain D,L-methionine. According to the invention, raw materials used in the method are cheap and easily available, the intermediate 2-hydroxy-4-methylthiobutyronityile has stable properties, prepared 2-amino-4-methylthiobutyronityile has high yield and high purity, and D,L-methionine obtained after continued production has the advantages of high yield, high purity, great bulk density and low total production cost.