646-06-0Relevant articles and documents
Comparative Analysis of Electronic States of Saturated Dioxa and Dithia Heterocycles and Their Radical Cations
Momose, Takamasa,Tanimura, Ryuji,Ushida, Kinimori,Shida, Tadamasa
, p. 5582 - 5586 (1987)
ESR spectra of the radical cations of 1,3-dioxa- and 1,3-dithiacyclopentanes and their 2-methylated derivatives were studied both experimentally and theoretically.The orbital interaction analysis based on the localized orbital indicates that the order of the two highest occupied molecular orbitals is reversed between the dioxa and the dithia systems.It is concluded that the reversal is caused by the interaction of the orbital localized on the methylene C-H bonds of carbon atom 2 with the "out of plane" lone-pair MO composed of the lone-pair orbitals on the oxygen and the sulfur atoms.The use of the usual canonical orbital and the internally consistent SCF orbital proposed by Davidson as the base is discussed comparatively.
Biomass alcoholysis method for petroleum-based plastic POM
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Paragraph 0030-0051, (2021/05/01)
The invention discloses a biomass alcoholysis method for petroleum-based plastic POM. According to the method, simple biomass derivative alcohol and the petroleum-based plastic POM are allowed to generate a cyclic acetal product through dehydration condensation under catalytic conditions; low reaction cost and high added value are realized, and only water is byproduced and is easy to separate; and an obtained product has high added value, can be used for preparing organic solvents such as lignin and chromatographic analysis solvents, metal surface treatment agents or medical intermediates and monomers, realizes green, efficient and low-cost recovery, and has a high practical application value.
Efficient Plastic Waste Recycling to Value-Added Products by Integrated Biomass Processing
Beydoun, Kassem,Klankermayer, Jürgen
, p. 488 - 492 (2020/01/24)
The industrial production of polymeric materials is continuously increasing, but sustainable concepts directing towards a circular economy remain rather elusive. The present investigation focuses on the recycling of polyoxymethylene polymers, facilitated through combined catalytic processing of polymer waste and biomass-derived diols. The integrated concept enables the production of value-added cyclic acetals, which can flexibly function as solvents, fuel additives, pharmaceutical intermediates, and even monomeric materials for polymerization reactions. Based on this approach, an open-loop recycling of these waste materials can be envisaged in which the carbon content of the polymer waste is efficiently utilized as a C1 building block, paving the way to unprecedented possibilities within a circular economy of polyoxymethylene polymers.
Ruthenium-Catalyzed Synthesis of Cyclic and Linear Acetals by the Combined Utilization of CO2, H2, and Biomass Derived Diols
Beydoun, Kassem,Klankermayer, Jürgen
supporting information, p. 11412 - 11415 (2019/07/18)
Herein a transition-metal catalyst system for the selective synthesis of cyclic and linear acetals from the combined utilization of carbon dioxide, molecular hydrogen, and biomass derived diols is presented. Detailed investigations on the substrate scope enabled the selectivity of the reaction to be largely guided and demonstrated the possibility of integrating a broad variety of substrate molecules. This approach allowed a change between the favored formation of cyclic acetals and linear acetals, originating from the bridging of two diols with a carbon-dioxide based methylene unit. This new synthesis option paves the way to novel fuels, solvents, or polymer building blocks, by the recently established “bio-hybrid” approach of integrating renewable energy, carbon dioxide, and biomass in a direct catalytic transformation.
A method for preparing 1, 3 - oxa naphthenic (by machine translation)
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Paragraph 0085; 0086-0090, (2019/05/16)
The invention discloses a 1, 3 - oxa naphthenic preparation method, the method comprises: diol, poly formaldehyde in water and ionic liquid catalyst in the presence of a cyclization reaction, containing the reaction product of the compound; wherein said diol is ethylene glycol or diethylene glycol; when the diol is ethylene glycol when, the target compound is 1, 3 - dioxolo; when the diol is diethylene glycol when, the target compound is 1, 3, 6 - heterocyclic octane; the ionic liquid catalyst comprises a cation and anion, the cation is selected from the isoquinoline kind of positive ion, quinoline kind of positive ion and benzimidazole in at least one of the kind of positive ion. The method of the invention the kind of positive ion cation is isoquinoline, quinoline kind of positive ion or benzimidazole kind of positive ion of the ionic liquid as catalyst to prepare 1, 3 - oxa naphthenic, mild reaction conditions, high product yield, catalyst is environment-friendly. (by machine translation)
Photocatalytic Synthesis of 1,3-Dioxacyclanes from Diols and Primary Alcohols Effected by a System FeCl3–NaNO2/O2(Air)
Makhmutov
, p. 1710 - 1714 (2019/02/14)
Diols and primary alcohols were subjected to the action of a system FeCl3–NaNO2/O2 (air) under mercury lamp irradiation to synthesize unsubstituted and 2-methyl-1,3-dioxacyclanes: 1,3-dioxolane, 1,3-dioxepane, 1,3-dioxocane, 2-methyl-1,3-dioxolane, 2-methyl-1,3-dioxepane, 2-methyl-1,3-dioxocane. The probable mechanism of the photocatalytic synthesis of 1,3-dioxacyclanes was described by an example of 2-methyl-1,3-dioxolane.
Preparation method of cyclic acetal
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Paragraph 0028; 0029; 0030; 0031; 0032; 0033; 0035, (2017/08/29)
The invention discloses a preparation method of cyclic acetal. The method is characterized in that long-chain polyhydroxy compounds and small-molecular aldehydes are used as the substrates, long-chain weak-polarity molecules are used as the solvent, and the aldehydes are condensed with the hydroxyl groups at two ends of the polyhydroxy compounds under the effect of a catalyst to form the intramolecular cyclic acetal. Compared with a traditional acetal preparation method, the method has the advantages that the property differences of the solvent, reactants and the substrates are utilized to allow the aldehydes to be easy to react with the hydroxyl groups, and the cyclic acetal proportion in the product is high; the conversion rate of the aldehyde compounds reaches above 80%, and the selectivity of the cyclic acetal can reach above 80%.
Preparation method of 1,3-dioxolane
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Paragraph 0016; 0017; 0018; 0019; 0020; 0021; 0022-0045, (2017/08/29)
The invention discloses a preparation method of 1,3-dioxolane. The preparation method comprises the steps of carrying out a reaction by taking ethylene glycol and polyformaldehyde as raw materials and adding right amount of N86 type ionic liquid catalyst; drying the obtained product with solid caustic soda, rectifying, adding right amount of antioxidant and evenly mixing to obtain the target product 1,3-dioxolane. The preparation method has the advantages of being less in consumption of the catalyst, short in reaction time, low in reaction temperature, high in product purity, and the like.
PROCESS FOR REMOVING FORMALDEHYDE FROM A COMPOSITION COMPRISING GLYCOLALDHEDYDE
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Page/Page column 15, (2014/09/16)
A process for reducing the percentage by weight of formaldehyde present in a composition comprising glycolaldehyde, wherein formaldehyde is transformed into one or more formaldehyde acetal(s) and removed from the reactive distillation reaction solution by reactive distillation in the presence of at least one alcohol and a catalyst.
Reactions of cyclic boric acids esters with paraformaldehyde
Brusilovskii, Yu. E.,Kuznetsov
experimental part, p. 542 - 544 (2011/06/22)
Reactions of five- and six-membered cyclic esters of boric acids with paraformaldehyde lead to the corresponding 1,3-dioxacycloalkanes. It is shown that trans-isomers of 2,4,5-substituted 1,3,2-dioxaborinanes react faster than their cis-isomers.
