- 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 METHIONINE
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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.
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Page/Page column 15
(2020/07/07)
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- Titanium-Catalyzed Cyano-Borrowing Reaction for the Direct Amination of Cyanohydrins with Ammonia
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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.
- Li, Qing-Hua,Li, Zhao-Feng,Tao, Jing,Li, Wan-Fang,Ren, Li-Qing,Li, Qian,Peng, Yun-Gui,Liu, Tang-Lin
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supporting information
p. 8429 - 8433
(2019/10/14)
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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 0144-0146
(2019/06/24)
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- Clean production method of methionine
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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.
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Paragraph 0039; 0043; 0048; 0053; 0058; 0063; 0067; 0071; 00
(2017/08/25)
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- METHOD FOR PRODUCING METHIONINE
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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.
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Paragraph 0034
(2017/10/10)
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- Prebiotic synthesis of aminooxazoline-5′-phosphates in water by oxidative phosphorylation
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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.
- Fernández-García,Grefenstette,Powner
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supporting information
p. 4919 - 4921
(2017/07/11)
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- Prebiotic selection and assembly of proteinogenic amino acids and natural nucleotides from complex mixtures
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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.
- Islam, Saidul,Bu?ar, Dejan-Kre?imir,Powner, Matthew W.
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p. 584 - 589
(2017/05/31)
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- Inexpensive high-purity D, method for the preparation of L-methionine
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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.
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Paragraph 0049; 0051
(2017/02/24)
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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 production of methionine
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A process for the production of methionine which comprises (a) hydrolyzing the methionine amide in the presence of a catalyst comprising titanium to produce ammonium methioninate, said catalyst having a porosity of from 5 to 1000 nm, a total pore volume of from 0.2 to 0.55 cm3/g and a surface area of from 30 to 150 m2/g, and (b) a second step of recuperating methionine from the ammonium methioninate salt by removing ammonia. Also claimed is an industrial process for the production of methionine incorporating the aforementioned hydrolysis.
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