77-76-9Relevant articles and documents
Pressure Stabilization and Solvation Thermodynamics of a Hemiketal Reaction Intermediate
Gift, Alan D.,Ben-Amotz, Dor
, p. 11459 - 11462 (2000)
This work reports the first pressure stabilization of a hemiketal intermediate, 2-methoxy-2 propanol, formed in the reaction of acetone and methanol, observed using Raman spectroscopy. Acetone dissolved in methanol is found to undergo a two-step reaction, with the ketal 2,2-dimethoxy-propane as the final product and the hemiketal observed as an intermediate. In a more dilute stoichiometric mixture of acetone and methanol in liquid tetrahydrofuran (THF), quantitative formation of the hemiketal is observed at pressures above 2 GPa. The complete set of reaction thermodynamic functions (ΔH0, ΔV0, ΔS0, ΔG0, ΔU0, ΔA0) is obtained for the hemiketal formation reaction in THF as a function of temperature and pressure and compared with previous measurements of ΔH0, ΔS0, and ΔG0 for acetone dissolved in methanol. Comparisons with quantum calculations for the isolated reactant and product species are used to completely quantitate the effects of solvation on the hemiketal formation reaction.
On the origin of nitrogen-containing promoters in the cobalt-catalyzed methoxycarbonylation of epoxides
He, Jianghua,He, Lin,Li, Zhen,Liu, Jianhua,Liu, Mengli,Wang, Fang,Xia, Chungu,Yun, Dong,Zeng, Bo
, (2021/07/26)
The detailed promotion mechanism of nitrogenous compounds in the cobalt-catalyzed methoxycarbonylation of epoxides has not been studied to date. Herein, we present the intrinsic correlation between nitrogenous promoters and activity and selectivity in the alkoxycarbonylation of epoxides by a comprehensive in situ IR spectroscopy and DFT studies. In situ IR spectroscopy confirmed the acid-base neutralization of the nitrogenous promoters and HCo(CO)4, resulting in reduction of the acidity of the catalyst. With the reduced acid-derived activity for formation of ethers as by-products, the selectivity of desired esters was increased. DFT calculations showed that a nitrogenous base could facilitate the methanolysis of cobalt-acyl species with lowered activation energy, which is considered to be the rate-determining step in the catalytic cycle. As a result, the reaction activity towards carbonylation was also improved by nitrogenous promoters. The present studies will provide new insights to the long-term confusing problems in epoxides carbonylation.
Preparation method of 2, 2-dimethoxypropane
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Paragraph 0026; 0027; 0028; 0029; 0030; 0031; 0032, (2019/01/24)
The invention discloses a preparation method of 2, 2-dimethoxypropane. The method adopts methanol and acetone as the raw materials, utilizes a metal oxide modified SO4/SnO2 catalyst to catalyze reaction, and includes the reaction steps of: a) subjecting methanol and acetone to preheating vaporization by a preheater respectively, and controlling the preheating temperature at 65-95DEG C; b) letting the vaporized methanol and acetone enter the reactor respectively, and contacting the vaporized methanol and acetone with the metal oxide modified SO4/SnO2 catalyst for catalytic reaction in the reactor at a temperature of 83-95DEG C so as to obtain a crude product containing 2, 2-dimethoxypropane and unreacted methanol and acetone. Specifically, the metal oxide is one of or a mixture of several of Fe2O3, Al2O3 and Ga2O3. The method adopted by the invention is carried out at high temperature, solves the problem of long reaction time at low temperature, has high single conversion rate,and does not introduce new impurities are introduced in the subsequent concentration process.
Method for preparing 2,2-dimethoxy propane
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Paragraph 0032; 0034; 0035; 0036; 0037; 0039-0041, (2019/04/02)
The invention relates to a method for preparing 2,2-dimethoxy propane. The method comprises the following steps: co-boiling methanol and acetone in a multi-tower serial connected tower type reactor tocarry out a condensation reaction, controlling the reaction pressure of the tower type reactor at 700Pa to 2.0KPa and a tower kettle reaction temperature at 2-18 DEG C, collecting generated azeotropefrom a tower top, and separating, so as to obtain 2,2-dimethoxy propane. By adopting the method, synthesis and separation of the 2,2-dimethoxy propane are simultaneously carried out in the tower typereactor, and complex aftertreatment of products can be avoided.
2,2-dimethoxypropane production method
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Paragraph 0024-0037, (2019/10/23)
The invention discloses a 2,2-dimethoxypropane production method. Methanol and acetone are used as raw materials, strong acid cation exchange resin serves as a catalyst, super absorbent resin serves as a dehydrating agent, and a product is obtained through reduced pressure rectification. The super absorbent resin can be recycled after hot air drying, and a mixture of a small quantity of methanol,acetone and 2,2-dimethoxypropane and water after drying can be separated through pressurized condensation, the separated water can be discharged directly, and the separated mixture of methanol, acetone and 2,2-dimethoxypropane are returned to a fixed bed reactor to continue to participate in reaction. The method is simple in process, high in continuity and low in cost, the total yield of productsis high and is greater than 65%, high quality is achieved while the purity is higher than 99%, and a high industrial application value is achieved.
Hyper-Cross-Linked Polyacetylene-Type Microporous Networks Decorated with Terminal Ethynyl Groups as Heterogeneous Acid Catalysts for Acetalization and Esterification Reactions
Sekerová, Lada,Lhotka, Miloslav,Vysko?ilová, Eli?ka,Faukner, Tomá?,Slováková, Eva,Brus, Ji?í,?erveny, Libor,Sedlá?ek, Jan
, p. 14742 - 14749 (2018/09/25)
Heterogeneous catalysts based on materials with permanent porosity are of great interest owing to their high specific surface area, easy separation, recovery, and recycling ability. Additionally, porous polymer catalysts (PPCs) allow us to tune catalytic activity by introducing various functional centres. This study reports the preparation of PPCs with a permanent micro/mesoporous texture and a specific surface area SBET of up to 1000 m2 g?1 active in acid-catalyzed reactions, namely aldehyde and ketone acetalization and carboxylic acid esterification. These PPC-type conjugated hyper-cross-linked polyarylacetylene networks were prepared by chain-growth homopolymerization of 1,4-diethynylbenzene, 1,3,5-triethynylbenzene and tetrakis(4-ethynylphenyl)methane. However, only some ethynyl groups of the monomers (from 58 to 80 %) were polymerized into the polyacetylene network segments while the other ethynyl groups remained unreacted. Depending on the number of ethynyl groups per monomer molecule and the covalent structure of the monomer, PPCs were decorated with unreacted ethynyl groups from 3.2 to 6.7 mmol g?1. The hydrogen atoms of the unreacted ethynyl groups served as acid catalytic centres of the aforementioned organic reactions. To the best of our knowledge, this is first study describing the high activity of hydrogen atoms of ethynyl groups in acid-catalyzed reactions.
Hierarchical porous organic polymer as an efficient metal-free catalyst for acetalization of carbonyl compounds with alcohols
Kim, Joong-Jo,Lim, Cheang-Rae,Reddy, Benjaram M.,Park, Sang-Eon
, p. 43 - 50 (2018/04/05)
An efficient melamine-porous organic polymer (M-POP) as N-functionalized organic polymer catalyst was synthesized with melamine and terephthalaldehyde by a facile microwave-assisted method. The synthesized M-POP exhibited a high specific surface area with hierarchical pore structure of both mesoporosity and microporosity. The rich N-moieties namely, C[dbnd]N and N–H from the melamine precursor were found to show hydrogen-bonding ability with various organic molecules such as carbonyl compounds. This was illustrated in the acetalization of aldehydes and ketones with methanol or ethylene glycol under mild conditions as a metal-free H-bonding catalyst with high product selectivity. The superior catalytic performance of M-POP was attributed to the availability of a large number of H-bonding sites both as H-donor and H-acceptor between the reactants and the catalyst.
A 2, 2 - dimethoxy propane preparation method (by machine translation)
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Paragraph 0014; 0016; 0017; 0019; 0020; 0022; 0025, (2019/01/08)
The invention discloses 2, 2 - dimethoxy propane synthesis in the technical field of a 2, 2 - dimethoxy propane preparation method, this invention adopts the indirect method for the preparation of 2, 2 - dimethoxy propane, step (1) the propylene glycol and acetone reaction, to produce 2, 2, 4 - trimethyl - 1, 3 dioxolane, in order to water-free ferric sulfate as a catalyst, not only high catalytic efficiency, and insoluble in the reaction system, as compared with the other soluble strong catalyst, its reaction is apt to separation, the reaction operation is simplified, and can be recycled, petroleum ether as a sub-agent, through the return water diversion, the water generated by the reaction out of the system the outer, right to in order to facilitate the reaction, the reaction is more fully, at the same time shorten the reaction time, step (2) adopting the step (1) product 2, 2, 4 - trimethyl - 1, 3 dioxolane and methanol reaction, the preparation of 2, 2 - dimethoxy propane, in order to water-free three-aluminum chloride as the catalyst, catalytic effect, and finally to the preparations 2, 2 - dimethoxy propane and higher yield at the same time the preparation time is short. (by machine translation)
PROCESS OF PRODUCTION OF SPECIFIC ACETALS AND KETALS
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Page/Page column 22, (2016/08/10)
The present invention relates to a method to produce specific acetals and ketals. The acetals and ketals, which are produced by the process according to the present invention are the ones of formula (I) wherein R is H or C1-, -C4 -alkyl, and R1 is C1-, -C4 -alkyl, and R2 is C1-, -C6 -alkyl. Surprisingly, it was found that the use of the specific ionic liquids and the use of a low reaction temperature (below room temperature) allows producing acetals and ketals of formula (I) in excellent yield in the absence of HCI as well as in the absence of any anhydrous calcium sulfate (or compounds having the same purpose).
Method for synthesizing 2,2-dialkoxyl propane
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Paragraph 0026, (2017/05/25)
The invention provides a method for synthesizing 2,2-dialkoxyl propane and co-produced 2-alkoxyl propane. Acetone, alcohol and tetraethyl orthosilicate serve as the raw materials and can be highly selectively synthesized into 2,2-dialkoxyl propane under certain conditions or react to generate 2,2-dialkoxyl propane and 2-alkoxyl propane at the same time. The method has the advantages that the synthesis process is simple, safe and environmentally friendly, product separation is easy, energy consumption is low, and product purity and yield are high.
