20 results about "Methoxide" patented technology

The present invention relates to a process for preparing at least one alkali metal methoxide by reactive distillation in at least one reaction column. At the lower end of the reaction column(s), the respective alkali metal methoxide dissolved in methanol is withdrawn. The methanol / water mixture obtained at the top of the reaction column(s) is separated by distillation in a rectification column.The vapours obtained at the upper end of the rectification column are compressed in at least two stages and the energy of the vapours compressed in each case is advantageously transferred to bottoms and side streams of the rectification column. This allows particularly efficient use of the energy of the compressed vapours in the process according to the invention. In addition, the energy in the product stream of alkali metal methoxide which is obtained at the lower end of the reaction column(s) is advantageously transferred to the vapour streams from the rectification column, especially before these vapours are subjected to compression.The energy from the compressed vapour may additionally be used for operation of the reaction column(s) or for operation of a reaction column in which a process for transalcoholization of alkali metal alkoxides is performed.

A method for controlling a reactive distillation column for effecting a transalcoholisation reaction, comprising feeding a metal methoxide into the reactive distillation column via a side feed; feeding a reactant alcohol into a lower part of the reactive distillation column; withdrawing methanol from the top of the reactive distillation column; and withdrawing a solution of a product metal alkoxide in the reactant alcohol from the bottom of the reactive distillation column; wherein the method comprises a process control scheme selected from: Scheme A: establishing a signal S1 which is responsive to a temperature in the rectifying section disposed above the feed of the metal methoxide; and manipulating in response to the signal S1 the feed amount of the reactant alcohol; Scheme B: establishing a signal S1 which is responsive to a temperature in the rectifying section disposed above the feed of the metal methoxide; and manipulating in response to the signal S1 the heat supplied to the bottom of the reactive distillation column. The invention also relates to a method for controlling a reactive distillation column for effecting a transalcoholisation reaction, comprising feeding a metal methoxide into the reactive distillation column via a side feed; feeding a reactant alcohol into a lower part of the reactive distillation column; causing an auxiliary alcohol to be present in the reactive distillation column; and optionally replenishing the auxiliary alcohol via a side feed located above the feed of the reactant alcohol and below the top of the column; withdrawing methanol from the top of the reactive distillation column; and withdrawing a solution of a product metal alkoxide in the reactant alcohol from the bottom of the reactive distillation column; wherein the method comprises a process control scheme selected from: Scheme C: establishing a signal S2 which is responsive to a temperature at a point located between the feed of the metal methoxide and the bottom of the reactive distillation column; and manipulating in response to the signal S2 the feed amount of the reactant alcohol; Scheme D: establishing a signal S2 which is responsive to a temperature at a point located between the feed of the metal methoxide and the bottom of the reactive distillation column; and manipulating in response to the signal S2 the heat supplied to the bottom of the reactive distillation column. The methods of the invention allow for improved controlling of a reactive distillation column for effecting a transalcoholisation reaction.

This invention provides a composite photocatalytic nanomaterial for visible light-driven degradation of microplastics and its preparation method. First, through reverse precipitation, the reactant of TaCl5 and methanol (tantalum methoxide) undergoes stepwise hydrolysis in the presence of ammonia as a precipitant, converting it into Ta hydroxide. The Ta hydroxide is then subjected to high-temperature heat treatment to obtain Ta2O5. Ta2O5 is further co-calcined with melamine to generate black Ta3N5. Next, ammonium molybdate and thiourea are used as catalysts to generate MoS2. x The reaction raw materials were used to prepare MoS2 by a hydrothermal method. x Furthermore, by adding an appropriate amount of polyvinylpyrrolidone, the final generated MoS₂ was influenced. x The morphology gives it a three-dimensional spherical structure; finally, through hydrothermal reaction, Ta3N5 and MoS3 with a mass ratio of 1.75:3.8 are combined. x The dispersion was subjected to a hydrothermal reaction at 160℃ to finally prepare Ta3N5 / MoS x Composite photocatalytic nanomaterials. The preparation process is simple and easy to operate. Furthermore, Ta3N5 / MoS... x Composite photocatalytic nanomaterials exhibit exceptionally good degradation and reduction effects on polyethylene-ethyl acrylate under photocatalytic conditions.

The present application relates to the technical field of biodiesel preparation, and particularly relates to an integrated heat and power comprehensive biodiesel preparation system, which comprises a solar drying system, a zeolite activation system, a catalyst preparation system and a biodiesel preparation system. The solar drying system is used for cleaning eggshells, drying the cleaned eggshells and conveying the eggshells to the catalyst preparation system. The zeolite activation system is used for activating zeolite, improving the adsorption performance and ion exchange performance of the zeolite, recycling waste heat and conveying the activated zeolite to the catalyst preparation system. The catalyst preparation system is used for preparing calcium methoxide solid base catalyst. The solar drying system and the zeolite activation system are connected to the catalyst preparation system. The biodiesel preparation system is used for preparing biodiesel. The catalyst preparation system and the biodiesel preparation system are connected. The catalyst is prepared by using waste eggshells and methanol. Two wastes are recycled and utilized. High-temperature calcination and soaking are combined, so that the activation process of the zeolite is sufficient and thorough.

In a first aspect, the invention relates to an integrated process for simultaneously preparing n mixtures P(i) comprising alkali metal methoxide and methanol and for preparing solid alkali metal methoxide A(i)OMe, comprising providing n reactive distillation columns K(i); providing n aqueous liquid streams H(i), a given stream H(i) comprising a dissolved alkali metal hydroxide A(i)OH, wherein n is an integer with n≥2 and i=1…n; and providing a rectification column D; wherein the process comprises preparing the one or more alkali metal methoxides in the n reactive distillation column K(i) under reactive distillation conditions from the n streams H(i) and n streams G(i) comprising methanol, thereby obtaining n top streams W(i) comprising methanol and water; and obtaining n bottoms streams P(i) comprising alkali metal methoxide A(i)OMe and methanol; the process further comprising (a) subjecting at least a part of at least one of the n bottoms streams P(i) comprising alkali metal methoxide A(i)OMe and methanol in a separation unit SU to a solid separation, obtaining a residue enriched in alkali metal methoxide A(i)OMe compared to P(i), preferably containing solid alkali metal methoxide A(i)OMe, and a stream MR(i) comprising methanol; and (b) feeding at least a part of the stream comprising methanol MR(i) obtained in (a) to at least one reactive distillation column K(i) and / or feeding at least a part of the stream comprising methanol MR(i) obtained in (a) to rectification column D. A second aspect of the invention is directed to a chemical production unit for carrying out the process according to the first aspect of the invention. In a third aspect, the invention relates to a use of the chemical production unit according to the second aspect of the invention or of a process according to the first aspect of the invention for simultaneously producing n mixtures P(i) comprising alkali metal methoxide and methanol, n being an integer with n≥2 and i=1…n, wherein either at least 2 of the mixtures P(i) comprise different alkali metal methoxides A(i)OMe, and / or at least 2 of the mixtures P(i) comprise the same alkali metal alkoxide A(i)OMe at different concentrations.

The present invention relates to an integrated method for simultaneously preparing at least two mixtures comprising alkali metal methoxides and methanol in at least two parallel reactive distillation columns, wherein a methanol feed stream is provided using a rectification column, which is subsequently used as a methanol source for the reactive distillation column, and wherein the overhead feed stream of the reactive distillation column is used as a methanol source for the rectification column.

The invention discloses a high performance liquid detection method for purity of (1S, 4R)-4-amino-2-cyclopentene-1-methanol hydrochloride, which comprises the following steps of: preparing a solution sample by adopting a chromatographic column taking octadecylsilane chemically bonded silica as a filling agent and taking acetonitrile-a buffer solution containing 50mmoL / L sodium dihydrogen phosphate and 10mmoL / L sodium octanesulfonate in a volume ratio of (13: 87)-(17: 83) as a mobile phase; and calculating the purity of the sample according to a peak area normalization method. The method can effectively separate each component in a short time, and has the characteristics of simplicity and convenience in operation, high analysis efficiency and stable result.

The invention discloses a preparation method of 2 '-methoxy cytidine, and belongs to the technical field of synthesis of medical intermediates. Cytidine 1 is used as a raw material and forms a ring with sulfonyl chloride in an organic solvent to obtain an intermediate 2; reacting the intermediate 2 in an organic solvent at a high temperature to obtain epoxy cytidine 3; and finally reacting the epoxy cytidine 3 with magnesium methoxide to obtain the 2 '-methoxy cytidine. The synthesis steps are mild in overall condition, high in selectivity, less in side reaction, simple in refining method and high in operation feasibility; meanwhile, raw materials are cheap and easy to obtain, and the method is more suitable for industrial production compared with an existing route and has obvious cost advantages.

The invention relates to the technical field of chemical synthesis methods of aspartame, in particular to a preparation method for producing aspartame by recycling coupling mother liquor, which comprises the following steps: pre-adjusting the pH value of the aspartame coupling mother liquor in the existing production process by using a 32% sodium hydroxide solution, and then forming a water phase system with L-phenylalanine; the method comprises the following steps: feeding N-formyl-alpha-L-aspartic anhydride and a 32% sodium hydroxide solution step by step for coupling reaction, removing formyl through 36% hydrochloric acid, recycling coupling mother liquor, esterifying an intermediate through methanol hydrochloric acid to form hydrochloride, desalting a sodium carbonate solution, and washing and refining to obtain an aspartame finished product. According to the method, an organic solvent is replaced by a water-phase reaction medium, closed-loop recycling of the coupling mother liquor is achieved, wastewater discharge is reduced, high-quality aspartame can be prepared, and the method has the advantages of being high in product yield, excellent in quality, efficient, environmentally friendly and low in cost.

The application discloses a toughened CPVC power cable protection pipe and a preparation method thereof, and relates to the technical field of polymer materials.The application comprises the following components in terms of weight parts: functionalized cage silsesquioxane 40-42 parts; composite modified magnesium hydroxide 80-85 parts; double-shell modifier 28-30 parts; stannic methoxide 30-31 parts; calcium stearate 3-3.5 parts; stearic acid 2-2.5 parts; antioxidant 2-3 parts; rutile titanium dioxide 15-16 parts; chlorinated polyethylene 55-60 parts; polyethylene wax 4-5 parts; ultraviolet absorber 1-1.5 parts; and chlorinated polyvinyl chloride 780-800 parts.The introduction of the functionalized cage silsesquioxane, the composite modified magnesium hydroxide, the double-shell modifier, the stannic methoxide and other raw materials effectively improves the flame-retardant capacity, the smoke suppression, the impact resistance at low temperature, the aging resistance and the heat resistance of the CPVC power cable protection pipe.

Provided is a process for depolymerization of a poly(C2-C4 alkylene terephthalate), which comprises contacting a poly(C2-C4 alkylene terephthalate) with methanol and a catalyst chosen from potassium carbonate, sodium carbonate, magnesium methoxide, 1,8-diazabicyclo[5.4.0]undec-7-ene, and triazabicyclodecene, at a temperature sufficient to effect said depolymerization. The process of the invention can be carried out a substantially lower temperature and requires less methanol than necessary for zinc acetate-catalyzed reactions, and is sufficiently robust to tolerate lower-quality poly(C2-C4 alkylene terephthalate) scrap feeds.

The application provides a method for synthesizing sandalwood ether from melonal, comprising the following steps: melonal is subjected to etherification reaction with methanol under the action of a catalyst to obtain methoxymelonal, and a metal methoxide reagent is added to the methoxymelonal to obtain sandalwood ether. The synthesis route is novel and short, melonal which is cheap and easy to obtain is used as a raw material, sandalwood ether product is obtained through two-step reactions of etherification and Grignard addition, and the method has the advantages of high reaction yield, less waste, simple operation and the like, and is easy to scale up. Compared with the traditional route of using dihydromyrcene, the method does not involve high-pressure hydrogenation and does not produce methoxymethyl chavicol by-product, and the route yield is significantly improved.

The invention discloses a preparation method and application of a biomass shell derived mesoporous cobalt-based NiCo (OH) 2 nanodisk. The preparation method comprises the following steps: preparing a calcium oxide precursor by taking waste biomass calcium as a raw material, reacting in methanol by taking nitrogen as a shielding gas to obtain a reaction intermediate calcium methoxide, and then adding cobalt chloride hexahydrate and nickel chloride hexahydrate for ion exchange to obtain the two-dimensional mesoporous NiCo (OH) 2 nano material. The nano material prepared by the preparation method disclosed by the invention shows excellent photocatalytic CO2 reduction performance, and the CO yield is excellent. Meanwhile, the preparation process is simple and convenient, industrial batch production can be achieved, and optimization of environmental benefits can be taken into account while economic value is created.

The present invention relates to a method for producing at least one alkali metal methoxide by reactive distillation in at least one reaction column. The respective alkali metal methoxide dissolved in methanol is removed at the bottom of the reaction column. The methanol / water mixture obtained at the top of the reaction column is separated by distillation in a rectification column. The energy of the vapor obtained at the top of the rectification column is transferred to a liquid or gaseous heat transfer medium, which is compressed in at least two stages. The energy of each compressed heat transfer medium is advantageously transferred to the bottom stream and a side stream of the rectification column. This allows for particularly energy-efficient use of the vapor energy in the process according to the invention. The energy of the compressed heat transfer medium can additionally be used for operating the reaction column or for operating a reaction column in which a process for alcohol exchange of alkali metal alkoxides is carried out.

A method for production of at least one sphingolipid of formula (1), or a composition thereof. The method comprising reacting at least one lysosphingolipid of formula (2), or a salt thereof: with a compound of formula (3): wherein W, R1, R2, R3, and R4 are as defined as for the sphingolipid of formula (1), and wherein, said reacting is performed in the presence of a base of formula (4): wherein n is 1, 2, or 3; m is 1 or 2; X is selected from Na+, K+, NH4 +, Mg2+, or Ca2+; Y is selected from OH-, CO3 2-, HCO3 -, PO4 3-, methoxide, acetate, citrate, or succinate.

The present invention relates to a method for producing at least one alkali metal methoxide by reactive distillation in at least one reaction column. At the bottom of the reaction column, the respective alkali metal methoxide dissolved in methanol is withdrawn. The methanol / water mixture obtained at the top of the reaction column is separated by distillation in a rectification column. The vapor obtained at the top of the rectification column is compressed in at least two stages, and the energy of each compressed vapor is advantageously transferred to the bottom stream and the side stream of the rectification column. This allows the method according to the invention to use the energy of the compressed vapor particularly efficiently. Furthermore, the energy of the alkali metal methoxide product stream obtained at the bottom of the reaction column is advantageously transferred to the vapor stream from the rectification column, which is then subjected, in particular, to compression. The energy of the compressed vapor can further be used to operate the reaction column or to operate a reaction column in which a process for alcohol exchange of alkali metal alkoxides is carried out.

According to the present invention, a polymer (C) is obtained by adding a metal methoxide to a polymer (B) that has a hydroxyl group, and subsequently devolatilizing the methanol. A polymer (D) is obtained by reacting an epoxy compound (G1) that has a carbon-carbon unsaturated bond. No metal methoxide is added after the step for obtaining the polymer (D). Subsequently, a halogenated hydrocarbon compound (G2) that has a carbon-carbon unsaturated bond is reacted so as to obtain a polymer (A). The addition amount of the metal methoxide is 1.05-1.35 equivalents with respect to the hydroxyl group of the polymer (B), and the addition amount of the compound (G2) is 4.0 equivalents or less with respect to the hydroxyl group of the polymer (B). A hydrosilane compound that has a reactive silicon group may be additionally reacted with the polymer (A).

The application provides a preparation method and application of 3-methoxy-4-chlorobenzaldehyde, and the preparation method comprises the following steps: (1) mixing and reacting p-chlorobenzaldehyde with a bromination reagent and an additive to obtain 3-bromo-4-chlorobenzaldehyde; (2) mixing and reacting the 3-bromo-4-chlorobenzaldehyde with a methoxide and a catalyst to obtain the 3-methoxy-4-chlorobenzaldehyde. The preparation method provided by the application starts from inexpensive p-chlorobenzaldehyde as a raw material, compared with the existing process, the reaction material is inexpensive and easy to obtain, the reaction yield is high, and the reaction condition is gentle.

The present invention relates to a process for producing at least one alkali metal methoxide by reactive distillation in at least one reaction column. At the lower end of the reaction column(s), the respective alkali metal methoxide dissolved in methanol is withdrawn. The methanol / water mixture obtained at the top of the reaction column(s) is separated by distillation in a rectification column. The energy from the vapour obtained at the top of the rectification column is transferred to a liquid or gaseous heat transfer medium, and the gaseous heat transfer medium obtained as a result is compressed in at least two stages. The energy from the respectively compressed heat transfer medium is advantageously transferred to the bottom stream and sidestream from the rectification column. This enables particularly energy-efficient use of the energy from the vapour in the process of the invention. The energy from the compressed heat transfer medium may additionally be used for operation of the reaction column(s) or for operation of a reaction column in which a process for transalcoholization of alkali metal alkoxides is conducted.

The present invention relates to a novel and efficient process for the production of 2-methoxymalonate of formula (I) by reacting malonate of formula (II) with a methoxide of formula (III) under specific conditions by a nucleophilic substitution reaction.