78-85-3Relevant articles and documents
IMPROVED SAFE METHOD FOR TANDEM C-4 OXIDATION TO METHACRYLIC ACID
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Page/Page column 14-17, (2021/10/11)
The present invention relates to an improved process for the production of methacrylates, in particular methacrylic acid and/or methyl methacrylate (MMA). Furthermore, the present invention relates to a process and specific embodiments of this process for the safe and efficient production of these products from C-4-based raw materials, in particular those based on isobutylene or tert-butanol as raw materials. With this novel process, it is possible to operate such processes for a longer period of time without any safety or cleaning related shutdowns. This makes it possible to carry out such processes as simple, economic and environmentally friendly as possible.
Supported Rb- or Cs-containing HPA catalysts for the selective oxidation of isobutane
Dumeignil, Franck,Katryniok, Benjamin,Paul, Sébastien,Zhang, Li
, (2021/10/29)
Silica-supported catalysts based on Keggin-type heteropolyacids (HPAs) containing rubidium or cesium as counter cations have been prepared by the impregnation method and evaluated in the selective oxidation of isobutane to methacrolein and methacrylic acid. The catalysts were characterized by various techniques such as XRD, N2 physisorption, TGA, Raman spectroscopy, H2-TPR, and NH3-TPD in order to study their thermal stability, structural, and textural properties, acidity and reducibility. It was evidenced that the reducibility of the Keggin type HPAs was improved by supporting the active phase on SiO2. A loading of 40 wt% was the optimum for the selective oxidation of isobutane (IBAN) to methacrylic acid (MAA). The selectivities to MAA and methacrolein (MAC) at given conversion were increased when Cs+ was used as counter cation compared to Rb+. The same trend was observed for mono- and di-vanado-substituted phosphomolybdic acid, whereby the performance followed the order: CsV1/SiO2 > RbV1/SiO2 > CsV2/SiO2 > RbV2/SiO2. The density of acid sites was correlated to the catalytic activity, which underlines the importance of the acid sites for alkane activation.
SYSTEMS AND METHODS FOR REGIOSELECTIVE CARBONYLATION OF 2,2-DISUBSTITUTED EPOXIDES FOR THE PRODUCTION OF ALPHA,ALPHA-DISUBSTITUTED BETA-LACTONES
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Paragraph 0082, (2021/01/29)
Provided are methods of producing carbonyl compounds (e.g., carbonyl containing compounds) and catalysts for producing carbonyl compounds. Also provided are methods of making polymers from carbonyl compounds and polymers formed from carbonyl compounds. A method may produce carbonyl compounds, such as, for example α,α-disubstituted carbonyl compounds (e.g., α,α-disubstituted β-lactones). The polymers may be produced from α,α-disubstituted β-lactones, which may be produced by a method described herein.
MMA preparation method with isobutene including saturated hydrocarbon
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Paragraph 0033-0035; 0048, (2020/08/26)
The present invention relates to a method for preparing methyl methacrylate, including the steps of: (1) separating isobutene containing saturated hydrocarbons(n-butane and iso-butane) from flow of C4 cuts including butadiene, n-butene and isobutene through a catalytic distillation process; (2) producing methacrolein from the thus separated isobutene through primary oxidation reaction; (3) producing methacrylic acid from the thus produced methacrolein through secondary oxidation reaction; and (4) carrying out esterification of the thus produced methacrylic acid with methanol. It is possible to minimize introduction of nitrogen by virtue of high heat capacity and to reduce the size of a reactor and generation of gas in the rear end, thereby saving investment and cost and providing high cost-efficiency.(AA) Naptha steam cracker C4 mixture(BB) Butadiene(CC) Extractive distillation(DD) 2-butene(EE) Reactive distillation(FF) Isobutene, nandamp;iso-butane(GG) Produce methyl methacrylate(HH) Methyl methacrylateCOPYRIGHT KIPO 2020
PROCESS FOR PRODUCING METHYL METHACRYLATE
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Paragraph 0181-0222, (2020/10/03)
The present invention relates to a method for producing methyl methacrylate. According to the present invention, provided is a method for producing methyl methacrylate, which is capable of securing the safety of a process, while improving the catalyst life and increasing the production amount of methyl methacrylate.
PROCESS FOR PRODUCING METHACRYLIC ACID OR METHACRYLIC ACID ESTERS
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Page/Page column 16-17, (2020/03/02)
The present invention relates to a process for producing methacrylic acid or methacrylic acid esters. The present invention is directed to a new process for the production of methacrylic acid or alkyl methacrylate starting from Acrolein, which is available from glycerol or propane.
Catalytic synthesis of methacrolein: Via the condensation of formaldehyde and propionaldehyde with l-proline
Yu, Jiayuan,Jensen, Anker Degn,Wang, Lei,Li, Chunshan,Zhang, Suojiang
supporting information, p. 4222 - 4230 (2020/07/14)
Methacrolein (MAL) is an important chemical for the manufacture of methyl methacrylate and a key monomer in many polymerization reactions. In this study, l-proline was investigated as the catalyst for the aldol condensation of formaldehyde and propionaldehyde to produce MAL. The catalytic activity of the reaction system was closely related to the competition between the main reaction synthesizing MAL and the side reaction producing 2-methyl-2-pentenal, which could be modified by adjusting the operating parameters. The influences of several operating conditions, including temperature, reaction time and water content, on the catalytic performance of the system were systematically studied via a series of single-factor experiments, and the optimized reaction conditions were obtained. The mechanistic investigation via ESI-MS indicated that the reaction pathway followed the Mannich route. Experimental and theoretical kinetic analyses of the l-proline-catalyzed aldol condensation reaction were performed, and the reaction orders of the reactants were obtained by regression. The results showed that l-proline was an efficient catalyst for the production of MAL via aldol condensation under mild conditions.
Nickel-Catalyzed Asymmetric Reductive 1,2-Carboamination of Unactivated Alkenes
He, Jun,Xue, Yuhang,Han, Bo,Zhang, Chunzhu,Wang, You,Zhu, Shaolin
supporting information, p. 2328 - 2332 (2020/01/08)
Starting from diverse alkene-tethered aryl iodides and O-benzoyl-hydroxylamines, the enantioselective reductive cross-electrophilic 1,2-carboamination of unactivated alkenes was achieved using a chiral pyrox/nickel complex as the catalyst. This mild, modular, and practical protocol provides rapid access to a variety of β-chiral amines with an enantioenriched aryl-substituted quaternary carbon center in good yields and with excellent enantioselectivities. This process reveals a complementary regioselectivity when compared to Pd and Cu catalysis.
CONTINUOUS PROCESS FOR PREPARING METHACROLEIN
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Page/Page column 9-10, (2020/03/15)
The present invention relates to a continuous process for preparing methacrolein by a Mannich condensation reaction of formaldehyde with propanal, in which a methacrolein polymerisation inhibitor is introduced during the production process and a part thereof is recycled back into the reactor where the Mannich condensation reaction is carried out.
Catalyst-controlled regioselective carbonylation of isobutylene oxide to pivalolactone
Hubbell, Aran K.,Lamb, Jessica R.,Klimovica, Kristine,Mulzer, Michael,Shaffer, Timothy D.,MacMillan, Samantha N.,Coates, Geoffrey W.
, p. 12537 - 12543 (2020/11/10)
Poly(pivalolactone) (PPVL) is a crystalline polyester with attractive physical and mechanical properties; however, prohibitively expensive syntheses of pivalolactone have thwarted efforts to produce PPVL on an industrial scale. Therefore, we developed a class of highly regioselective sandwich-type catalysts for the carbonylation of isobutylene oxide. These sterically encumbered complexes install carbon monoxide at the substituted epoxide carbon, generating a high level of contrasteric selectivity (up to >99:1). Further catalyst development improved catalyst solubility and reproducibility while maintaining high regioselectivity. In addition, a dibasic ester solvent extended catalyst lifetimes and suppressed side product formation. This contrasteric carbonylation of isobutylene oxide offers a route to sought-after pivalolactone and, therefore, PPVL.