- Method for synthesizing symmetric oxalate by using dimethyl oxalate and alcohols in one step
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The invention relates to a method for synthesizing symmetric oxalate, in particular to a method for synthesizing the symmetric oxalate by using dimethyl oxalate and alcohols in one step. The symmetricoxalate is synthesized by using the dimethyl oxalate and the high carbon alcohols such as ethanol, propanol, butanol and pentanol as reaction raw materials and by adopting a one-step synthesis method. A catalyst used in the method is a mesoporous-microporous composite multifunctional basic catalyst, and has the advantages that mesopores significantly improve the mass transfer efficiency, while micropores significantly enlarge the specific surface area of a carrier and improve the dispersion of an active center. 10% MgO-5% Al2O3-8% Fe2O3/Na-meso-Y is used as the catalyst, the raw material ethanol and the dimethyl oxalate are enabled to be subjected to reaction under the atmospheric pressure at the temperature of 100 DEG C under the condition that the space velocity is 2 h-1, wherein the molar ratio of the raw material ethanol to the dimethyl oxalate is equal to 20 to 1; the selectivity of the product diethyl oxalate is stabilized to be about 82%, and the steady state operation is performed for 1000h; the catalytic activity and the product selectivity are basically unchanged. The whole reaction path has the characteristics of being short in synthetic route, simple in process flow and high in raw material conversion rate and product selectivity, and enabling the catalyst to be stable and non-deactivated.
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Paragraph 0039; 0040
(2019/01/06)
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- Method for synthesizing diisoamyl oxalate by using particle immobilized catalyst
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The invention relates to a method for synthesizing diisoamyl oxalate by using a particle immobilized catalyst, comprising: using oxalic acid and isoamyl alcohol as materials, adding an immobilized catalyst prepared by particle tangling forming process, and synthesizing in a reactor, diisoamyl oxalate; after reacting, removing the particle immobilized catalyst online without cooling, and rectifying and purifying a product; or separating and recycling residual excessive isoamyl alcohol in a reaction liquid, and removing the particle immobilized catalyst.The method has the advantages that the step of removing the catalyst from the reaction liquid is simplified, post-treatment cost is reduced, and conditions are provided for removing the catalyst online without cooling; side reactions in reaction later stage and separation phase are inhibited, product quality is improved, and activity of the catalyst is protected; reaction catalytic activity is high, the catalyst is reusable, the product is easy to separate, the production process is simplified, and production cost is lowered.
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Paragraph 0015; 0016; 0017
(2016/11/02)
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- Environment-friendly production method of diisopentyl oxalate without adding water-carrying agent
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The invention relates to an environment-friendly production method of diisopentyl oxalate without adding a water-carrying agent.Oxalic acid and isoamyl alcohol serve as raw materials, an esterification reaction is performed under the action of a catalyst, reactant isoamyl alcohol and water form azeotrope, the azeotrope is condensed and subjected to water diversion, the isoamyl alcohol subjected to water diversion is recycled, isoamyl alcohol and diisopentyl oxalate are separated after a reaction ends, and the diisopentyl oxalate product is obtained.The environment-friendly production method of diisopentyl oxalate has the advantages that by means of the azeotropic characteristic of isoamyl alcohol and water, no water-carrying agent needs to be additionally added, pollution of newly-added substances is avoided, production links are simplified, production cost is reduced, an esterification reaction is easy, and separation and purification of the product are easy; meanwhile, water in the product is separated through a membrane separation method, the process is environmentally friendly, and environment-friendly production of the whole technological process of diisopentyl oxalate is achieved.
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Paragraph 0021; 0022; 0023
(2016/12/01)
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- Esterification in dry media using ferric perchlorate adsorbed on silica gel
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Adsorption of Fe(ClO4)3(H2O)6 onto chromatographic grade silica gel in the presence of alcohol ( to be used for esterification ) produces a supported reagent, Fe(ClO4)3(ROH)6/SiO2. This reagent, has been found effective for the rapid and high yield of esters, on grinding in the presence of carboxylic acids using pestle and mortar in the solid state.
- Parmar, Anupama,Kaur, Jatinder,Goyal, Rita,Kumar, Baldev,Kumar, Harish
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p. 2821 - 2826
(2007/10/03)
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