- Method for preparing p-xylylene dichloride through ultraviolet-induced catalysis
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The invention relates to a method for preparing p-xylylene dichloride by ultraviolet-induced catalysis, wherein the method comprises the following steps: step 1, adding p-xylene and a catalyst into areaction kettle, and slowly heating to a certain temperature; turning on an ultraviolet lamp, introducing chlorine gas from the bottom (or inserting a gas guide pipe into the bottom), and controllingthe introduction rate of the chlorine gas until a tail gas absorption liquid is slightly bubbled; when the temperature rises to 100 DEG C, heating is stopped, carrying out heat preservation, and introducing chlorine gas at the constant temperature for reaction; and after 5 hours, monitoring the reaction process by gas chromatography to obtain a high-temperature reaction solution; step 2, pre-adding a large amount of water into another kettle with strong stirring, and rapidly adding the reaction solution obtained in the step 1 into the water under strong stirring to form a large amount of whiteprecipitates; step 3, carrying out suction filtration, and rinsing the obtained white solid with water several times. and step 4, drying to obtain the target product p-xylylene dichloride.
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Paragraph 0035-0049
(2021/01/15)
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- NMP-mediated chlorination of aliphatic alcohols with aryl sulfonyl chloride for the synthesis of alkyl chlorides
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NMP-mediated chlorination of aliphatic alcohols has been developed for the synthesis of alkyl chlorides. This facile, efficient and practical approach used simple and readily available aryl sulfonyl chlorides as the chlorination reagent for the construction of C–Cl bond in good to excellent yields with mild conditions and broad substrate scope.
- Zheng, Dagui,Mao, Liu-Liang,Zhu, Xian-Hong,Zhou, An-Xi
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supporting information
p. 2793 - 2800
(2018/11/06)
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- Mild Aliphatic and Benzylic Hydrocarbon C-H Bond Chlorination Using Trichloroisocyanuric Acid
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We present the controlled monochlorination of aliphatic and benzylic hydrocarbons with only 1 equiv of substrate at 25-30 °C using N-hydroxyphthalimide (NHPI) as radical initiator and commercially available trichloroisocyanuric acid (TCCA) as the chlorine source. Catalytic amounts of CBr4 reduced the reaction times considerably due to the formation of chain-carrying ·CBr3 radicals. Benzylic C-H chlorination affords moderate to good yields for arenes carrying electron-withdrawing (50-85%) or weakly electron-donating groups (31-73%); cyclic aliphatic substrates provide low yields (24-38%). The products could be synthesized on a gram scale followed by simple purification via distillation. We report the first direct side-chain chlorination of 3-methylbenzoate affording methyl 3-(chloromethyl)benzoate, which is an important building block for the synthesis of vasodilator taprostene.
- Combe, Sascha H.,Hosseini, Abolfazl,Parra, Alejandro,Schreiner, Peter R.
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p. 2407 - 2413
(2017/03/11)
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- Method for preparing chlorohydrocarbons from alcohols by using aryl sulfonyl chloride as chlorination agent
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The invention provides a method for preparing chlorohydrocarbons from alcohols by using aryl sulfonyl chloride as a chlorination agent. The method comprises the following steps: heating alcohols and aryl sulfonyl chloride in N,N-dialkyl substituted amide to react for 30 minutes, cooling the reaction product to room temperature, adding dichloromethane and water, carrying out extraction and skimming, washing the organic layer with saturated saline water, drying with anhydrous sodium sulfate, steaming to remove the solvent, and carrying out further separation and purification to obtain the chlorohydrocarbons. The method has the characteristics of cheap and accessible chlorination agent, simple technical process, short reaction time and the like, can obtain high reaction under the condition that the aryl sulfonyl chloride consumption is approximate to the stoichiometric quality, and can remove the reaction byproduct aryl sulfonic acid from the reaction mixture.
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Paragraph 0021; 0022
(2017/01/17)
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- Improved Halogenation of Methyl Aromatics and Methyl Heteroaromatics: Unexpected Reactivity of Tetrahalogeno-diphenylglycolurils
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1,3,4,6-Tetrachloro (TCDGU) and 1,3,4,6-tetrabromo-3α,6α-diphenylglycolurils smooth halogen oxidizers have been exploited in a new direction as reagents for free radical substitution toward some N-halosuccinimide nonreactive bis-heterocycles. An unexpected selectivity and reactivity were observed with methyl benzenes, methyl heterocycles, and methyl-bis-heterocycles of interest. A chemometric study has been performed to optimize five independent factors of the chlorination reaction with TCDGU. The predictive model was established either for the halogenation conversion and the ratio of monochlorination.
- Moretti, Florian,Poisson, Guillaume,Marsura, Alain
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p. 173 - 183
(2016/05/19)
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- Preparation method of p-xylylene dichloride
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The invention relates to a preparation method of p-xylylene dichloride and belongs to the technical field of organic chemical synthesis. The preparation method of the p-xylylene dichloride comprises the following steps: under the irradiation of an LED light source, carrying out reaction on p-xylene, an ionic liquid catalyst and chlorine in a solvent, so as to obtain a p-xylylene dichloride reaction liquid, then cooling and separating the p-xylylene dichloride reaction liquid, so as to obtain a p-xylylene dichloride crude product, and carrying out reduced pressure distillation on the p-xylylene dichloride crude product, so as to obtain the p-xylylene dichloride. The obtained p-xylylene dichloride has a melting point of 98-101 DEG C and the purity not less than 99%; the preparation method of the p-xylylene dichloride has the characteristics that the reaction speed is high, the yield is high and a solvent can be recycled, thereby being applicable to industrial production.
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Paragraph 0022; 0044; 0045; 0046; 0047; 0048; 0049-0051
(2016/10/07)
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- 1, 4-bis(chloromethyl)benzene synthesis technology
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The invention relates to a 1, 4-bis(chloromethyl)benzene synthesis technology and belongs to the technical field of organic chemical synthesis. The technology comprises that under LED light source irradiation, p-xylene and chlorine undergo a reaction in the presence of an ionic liquid catalyst to produce a 1, 4-bis(chloromethyl)benzene reaction solution, the 1, 4-bis(chloromethyl)benzene reaction solution is cooled and separated so that a 1, 4-bis(chloromethyl)benzene crude product is obtained, and the 1, 4-bis(chloromethyl)benzene crude product is subjected to vacuum rectification so that 1, 4-bis(chloromethyl)benzene is obtained. The 1, 4-bis(chloromethyl)benzene has a melting point of 98-101 DEG C and purity of 99% or more. The 1, 4-bis(chloromethyl)benzene synthesis technology is free of any solvent, guarantees high product purity, has the characteristics of high conversion rate, fast reaction rate and low cost and is suitable for industrial production.
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Paragraph 0043; 0044; 0045; 0046; 0047; 0048; 0049; 0050
(2016/10/24)
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- An experimental and theoretical study on imidazolium-based ionic liquid promoted chloromethylation of aromatic hydrocarbons
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The chloromethylation of aromatic hydrocarbons proceeded efficiently using the reusable imidazolium-based ionic liquid as promoter. Mild reaction conditions, enhanced rates, improved yields, recyclability of ionic liquids, and reagents' reactivity which is different from that in conventional organic solvents are the remarkable features observed in ionic liquids. The ionic liquids were recycled in three subsequent runs with no decrease in activity. In addition, the results of calculations with the Gaussian 98 suite of program are in good accordance with the experimental outcomes.
- Wang, Yun,Xi, Yanli
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p. 2196 - 2199
(2014/03/21)
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- Preparation of sensors on oligo- or poly (ethylene glycol) films on silicon surfaces
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A sensor that includes a) a silicon (Si) substrate having a surface; and b) a monolayer of oligoethylene glycol (OEG) bonded to the surface via silicon-carbon bonds. Regions of the OEG monolayer distal to the surface are functionalized with a ligand serving as a recognition element for a bioanalyte. The ligand is covalently bonded in these regions as a cycloadduct of a 1,3-dipolar cycloaddition reaction. A method of making a silicon surface that recognizes a biological specimen includes 1) hydrosilylating with a mixture that includes an oligoethylene glycol (OEG) substituted with an alkene at one end of the OEG and capped at the opposing end of the OEG and an oligoethylene glycol (OEG) substituted with an alkene at one end of the OEG and an alkyne having a protecting group at the opposing end of the OEG and 2) removing the protecting group from the alkyne; and 3) reacting the alkyne with a reagent in a 1,3-dipolar cycloaddition. The reagent in the 1,3-dipolar cycloaddition includes a portion capable of being recognized by a biological specimen.
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Page/Page column
(2013/05/08)
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- Efficient dichloromethylation of some aromatic hydrocarbons catalyzed by a new ionic liquid [C12minPEG800]br under homogeneous catalysis in aqueous media
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A series of new imidazolium-type ionic liquids based on polyethylene glycol have been prepared. The new recyclable temperature-dependant phase-separation system comprised of [C12minPEG800]Br and methylcyclohexane was also developed and successfully applied to the dichloromethylation of some aromatic hydrocarbons to prepare dichloromethyl-substituted hydrocarbons in excellent yields. The ionic liquid could be excellent recycled without any apparent loss of catalytic activity and little loss of weight even after 8 times recycling.
- Hu,Liu,Lu,Lu,Ge,Zhang
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experimental part
p. 131 - 141
(2012/01/03)
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- Facile synthesis of hypercrosslinked resin via photochlorination of p-xylene and succedent alkylation polymerization
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A combination of photochlorination of p-xylene and succedent Friedel-Crafts alkylation polymerization was firstly used in the preparation of the hypercrosslinked adsorptive resin. The data of GC-MS and GC showed that a series of chlorizates were produced when p-xylene was photochlorinated. Hypercrosslinked resins could be synthesized by copolymerization, self-polymerization of chlorizates or post crosslinking reaction. The chemical structure and micromorphology of the porous resins were characterized by BET, FT-IR, SEM and elementary analysis (EA). The results showed that the novel adsorptive resins possess high BET surface near to 1038 m2/g and large pore volumes range from 0.5 to 1.2 cm3/g.
- Bai, Ling Ling,Zhou, Yong Hao,Wang, Xiu Li,Yuan, Si Guo,Wu, Xian Li
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experimental part
p. 1115 - 1118
(2012/06/01)
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- Synthesis, characterization and property studies on a dinuclear copper(II) complex with dipyridine derivate and acetylacetone
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A dinuclear copper(II) complex of [Cu2(aceace) 4(dipyph)] [aceace = acetylacetone, dipyph = 1,4-di(4-pyridylethene- 2-yl-)benzene] has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction. It crystallizes in the monoclinic system, space group P21/c, with lattice parameters a = 7.9584(16) A, b = 18.594(4) A, c = 15.063(4) A, β = 120.97(2)° and Mr = 807.85 (C40H44Cu2N2O8), Z = 2. Each of the Cu2+ ion adopts a square pyramid geometry and coordinates with four oxygen atoms from two aceace ligands and one nitrogen atom from dipyph bidentate ligand. Magnetic measurement shows that the Weiss constant and Curie constant for the title compound are -0.22 K and 0.1154 emu·K/mol, respectively. Thermal stability data indicate that the title complex undergoes two steps decomposition and the residue is Cu 2O4. In the potential range of -1.5 ～ 0.8 V, the title complex represents an irreversible electrochemical process.
- Zhao, Pu Su,Guo, Zhi Yan,Sui, Jing,Wang, Jing,Jian, Fang Fang
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scheme or table
p. 49 - 52
(2011/11/06)
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- [emim]BF4-promoted chloromethylation of aromatic hydrocarbons
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The chloromethylation of aromatic hydrocarbons proceeded efficiently using the reusable ionic liquid [emim]BF4 as promoter. The reactions were completed in 5 h at 70°C with good yields and easy workup. Copyright Taylor & Francis Group, LLC.
- Wang, Yun,Shang, Zhi-Cai,Wu, Tian-Xing
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p. 3053 - 3059
(2007/10/03)
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- Scope and Limitations of a New Highly Selective Synthesis of Unsymmetrical Monomers for the Synthesis of Precursors toward Poly(arylenevinylene)s
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In our laboratory a precursor route to poly(p-phenylenevinylene) derivatives is developed in which unsymmetrically substituted p-xylene derivatives, possessing a benzylic sulfinylalkyl group, are used as monomers. Because of this unsymmetry, we were forced to investigate thoroughly the synthesis of these sulfoxides, as we start from symmetric and readily accessible molecules, namely, bis(halomethyl)-p-xylene derivatives. In a former publication, a new extremely effective route for the production of these unsymmetrically substituted sulfinyl monomers was presented. This paper expands upon these previously reported results. To examine the scope and limitations of this elegant route, this new method was applied to the synthesis of various derivatives not included in the initial work.
- van der Borght, Michael,Vanderzande, Dirk,Adriaensens, Peter,Gelan, Jan
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p. 284 - 289
(2007/10/03)
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- Highly Selective Route for Producing Unsymmetrically Substituted Monomers toward Synthesis of Conjugated Polymers Derived from Poly(p-phenylene vinylene)
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A new convenient route for producing unsymmetrically substituted sulfinyl monomers of precursor polymers toward poly(p-phenylene vinylene) is described. Upon treating a symmetrical bissulfonium salt with a thiolate anion, an unexpected high selectivity for the monosubstituted thioethers (90%) is obtained. Optimization of the reaction conditions showed that the stoichiometry of the reactants in this reaction is important to ensure the high selectivity and to prevent unwanted side reactions. Reaction of equimolar amounts of reagents at ambient temperature gave the best results. A mechanism consistent with these results, supported by UV-vis experiments, is presented. Selective oxidation of the thioethers yielded the sulfinyl monomers. By using this new route, it was possible to increase the overall yield by a factor of 2, as compared to the route previously used to obtain these compounds.
- Van Breemen, Albert J. J. M.,Vanderzande, Dirk J. M.,Adriaensens, Peter J.,Gelan, Jan M. J. V.
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p. 3106 - 3112
(2007/10/03)
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- Amino Acids, 9 - Reactions of 5-Oxoproline Derivatives with Phosphorus Pentachloride - Synthesis of Chloro-pyrrole-2-carboxylic Acid Derivatives
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N-Benzyl-4,5-dichloro-1H-pyrrole-2-carboxylic esters 6 are formed from N-benzyl-5-oxoproline esters 5 and PCl5 via differently chlorinated intermediates.The N-benzhydryl- L-3 and N-acyl-5-oxoproline esters L-4, on the other hand, suffer cleavage of the N-substituent in the course of this reaction sequence to give L-4,4,5-trichloro-3,4-dihydro-2H-pyrrole-2-carboxylic esters 18, which are dehydrohalogenated in the presence of base, yielding 4,5-dichloro-1H-pyrrole-2-carboxylic esters 20.These reactions provide the best access to 4,5-dichloro-1H-pyrrole-2-carboxylic acid derivatives which, in turn, can serve as precursors in the synthesis of pyoluteorin type compounds.
- Effenberger, Franz,Mueller, Wolfgang,Isak, Heinz
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