3052-50-4Relevant articles and documents
Method for preparing diacid diester compound under catalysis of deep eutectic solvent
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Paragraph 0055-0058, (2021/05/19)
The invention belongs to the technical field of organic synthesis, and discloses a method for preparing a diacid diester compound through catalysis of a deep eutectic solvent, wherein the deep eutectic solvent takes ammonium salt and ferric salt as hydrogen acceptors, takes p-toluenesulfonic acid as a hydrogen donor, takes diacid or anhydride of the diacid and an alcohol compound as raw materials, and adopts a one-pot method to prepare the diacid diester compound; and under the catalysis of the deep eutectic solvent, the esterification reaction is performed to generate the diester product. The selected deep eutectic solvent has characteristics of environmental protection, easy preparation, cheap components and easy recovery; the preparation method has characteristics of simple operation, simple separation, no water-carrying agent, repeated use of the deep eutectic solvent, and high diester yield.
Dichloro Butenediamides as Irreversible Site-Selective Protein Conjugation Reagent
Abegg, Daniel,Adibekian, Alexander,Afonso, Cláudia F.,Bernardes, Gon?alo J. L.,Corzana, Francisco,Laserna, Victor,Martin, Esther M.,Ravn, Peter
supporting information, p. 23750 - 23755 (2021/10/01)
We describe maleic-acid derivatives as robust cysteine-selective reagents for protein labelling with comparable kinetics and superior stability relative to maleimides. Diamide and amido-ester derivatives proved to be efficient protein-labelling species with a common mechanism in which a spontaneous cyclization occurs upon addition to cysteine. Introduction of chlorine atoms in their structures triggers ring hydrolysis or further conjugation with adjacent residues, which results in conjugates that are completely resistant to retro-Michael reactions in the presence of biological thiols and human plasma. By controlling the microenvironment of the reactive site, we can control selectivity towards the hydrolytic pathway, forming homogeneous conjugates. The method is applicable to several scaffolds and enables conjugation of different payloads. The synthetic accessibility of these reagents and the mild conditions required for fast and complete conjugation together with the superior stability of the conjugates make this strategy an important alternative to maleimides in bioconjugation.
A Br?nsted acidic, ionic liquid containing, heteropolyacid functionalized polysiloxane network as a highly selective catalyst for the esterification of dicarboxylic acids
Rajabi, Fatemeh,Wilhelm, Christian,Thiel, Werner R.
supporting information, p. 4438 - 4444 (2020/08/10)
A Br?nsted acidic, ionic liquid containing, heteropolyanion functionalized polysiloxane network was formed by self-condensation of dodecatungstophosphoric acid and a zwitterionic organosilane precursor containing both imidazolinium and sulfonate groups. The resulting hybrid material POS-HPA-IL was investigated as a catalyst for the selective esterification of dicarboxylic acids.
An empirical model for stereochemical control in the cyclization of cyclopropanetricarboxylic acid esters
Tanaka, Kento,Manabe, Hitomi,Irie, Raku,Oikawa, Masato
, p. 1314 - 1323 (2019/09/18)
Here, we report an empirical model for diastereoselective cyclopropanation of fumarate/maleate diesters with chloroacetate, sulfonium ylide, or ammonium ylide. With symmetrical fumarate/maleate diesters, cyclopropanation was found to proceed with a high level of diastereoselectivity in favor of the chiral isomer. In contrast, production of the meso isomer was observed in 3848% diastereoselectivity when unsymmetrical fumarate/maleate was employed. An improved synthesis of (N-desmethy)dysibetaine CPa in both racemic and enantiomeri-cally pure forms was furthermore achieved. Configurational analysis by experimental and calculated 13C NMR data is also reported.
Preparation method of chlorantraniliprole
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Paragraph 0028-0030; 0041-0043; 0054-0056, (2020/01/08)
The invention relates to the technical field of synthesis processes of insecticides, and discloses a preparation method of chlorantraniliprole, which comprises the following steps: 1) adding 4-8 partsof maleic anhydride and 4-8 parts of methanol into a single-necked bottle, stirring the mixture, heating to 50 DEG C, and carrying out heat preservation reaction for 0.5-1.5 hours to obtain monomethyl maleate; and 2) cooling 80-120 parts of a hydrogen bromide-glacial acetic acid solution to 0 DEG C, then dropwise adding 3-5 parts of the monomethyl maleate, after addition is completed, carrying out heat preservation and stirring for 3-7 min, so that a large amount of a yellow viscous substance appears, and the monomethyl 3-bromomaleate can be prepared. The invention discloses a preparation method of chlorantraniliprole. The maleic anhydride, 2,3-dichloropyridine and 2-amino-3-methylbenzoic acid are adopted as starting materials to synthesize the target compound chlorantraniliprole througha convergent reaction. The structure is determined through HNMR, the route is mild in reaction condition, easy and convenient to operate and separate, raw materials are easy to obtain, special equipment is not needed, industrial production is easy to achieve, the action mechanism is novel and unique, and wide application and development prospects are achieved.
Synthesis of α,β-unsaturated esters of perfluoropolyalkylethers (PFPAEs) based on hexafluoropropylene oxide units for photopolymerization
Bonneaud, Céline,Decostanzi, Mélanie,Burgess, Julia,Trusiano, Giuseppe,Burgess, Trevor,Bongiovanni, Roberta,Joly-Duhamel, Christine,Friesen, Chadron M.
, p. 32664 - 32671 (2018/10/15)
α,β-unsaturated esters are usually synthesized for polymer applications. However, the addition of maleate (cis-configuration) to a fluorinated moiety is challenging due to its potential isomerization during esterification. Various synthetic routes were attempted and led to very low conversion or side-products. The immiscibility of both reagents combined with an easy isomerization or attack on the double bond were potential explanations. In this paper, the synthesis of maleates oligo(hexafluoropropylene oxide) is reported by Steglich esterification and the reaction conditions are discussed depending on the molecular weight of the fluorinated moieties. After UV-curing, hydrophobic polymers were obtained by copolymerization with vinyl ethers by electron acceptor-donor systems.
AN IMPROVED PROCESS FOR THE SYNTHESIS OF DIMETHYL FUMARATE
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Paragraph 0027, (2017/05/10)
The present invention describes an improved process for the industrial scale production of dimethyl fumarate. The process involves a one-pot ring opening reaction of maleic anhydride to monomethyl maleate and isomerization into the corresponding monomethyl fumarate in presence of a Lewis acid. Finally the mono methyl fumarate was converted into the dimethyl fumarate by an acid catalyzed esterification reaction.
Synthesis process of dimethyl maleate
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Paragraph 0010, (2017/07/01)
The invention discloses a synthesis process of dimethyl maleate. The synthesis process comprises steps as follows: maleic anhydride and methanol are subjected to a reaction in a mono-esterification reaction kettle at the temperature of 70-100 DEG C, and monomethyl maleate is generated; monomethyl maleate enters a catalytic esterification tower from a tower, methanol steam enters the catalytic esterification tower from the position below upper liquid level of each layer of tower plate and is contacted with monomethyl maleate and a solid catalyst on the tower plate, and dimethyl maleate is generated. With the adoption of continuous production, energy utilization rate is increased by full use of waste heat of the esterification reaction; with the adoption of multiple methanol steam inputs, methanol steam is distributed on each tower plate, each tower plate forms one small reactor in a boiling state, the contact area of monomethyl maleate and methyl alcohol is increased, the contact time of monomethyl maleate and methyl alcohol is prolonged, the problem of uneven distribution of methanol in the tower due to liquefied reflow of the methyl alcohol steam in a rising process is solved, the reaction efficiency and the esterification rate are increased, the methanol utilization rate is increased, the production cost is reduced while the yield is increased, and the synthesis process is suitable for industrial application.
PROCESS FOR CARRYING OUT A REACTION IN A REACTION COLUMN
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Page/Page column 14-15, (2016/10/11)
A process for carrying out a reaction in a reaction column, said process comprising: providing a first reactant to the reaction column in the liquid phase; contacting said first reactant with an excess of a second reactant such that reaction takes place within the reaction column to form a low boiling product and a high boiling product, at least a portion of said second reactant being provided to the reaction column in the vapour phase; recovering an overhead stream from at, or near, the top of the reaction column, said overhead stream comprising unreacted second reactant and the low boiling product; and recovering a bottoms stream from at, or near, the bottom of the reaction column comprising the high boiling product; wherein at least a portion of the heat required to vaporise the second reactant provided to the reaction column in the vapour phase is provided by heat exchange in a heat exchanger with a hot stream generated within the process other than a hot stream generated within the reaction column.
PROCESS FOR THE PREPARATION OF DIALKYL SUCCINATE FROM MALEIC ANHYDRIDE
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Page/Page column 11; 12, (2015/05/05)
A process for the production of dialkyl succinate from a feedstock comprising maleic anhydride, said process comprising the steps of providing the feed in the liquid phase to a reactor operated at a temperature of at least about 150°C; contacting said feed with hydrogen at a pressure of at least about 300 psig in the presence of an acid tolerant catalyst and an alkanol wherein at least some of the carbon carbon double bonds of the maleic anhydride are hydrogenated to form succinic acid and that the heat generated promotes esterification to dialkyl succinate acid in situ; and recovering a stream comprising dialkyl succinate from the reactor.
