- Direct synthesis of diphenyl carbonate from phenol and carbon dioxide over Ti-salen-based catalysts
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Various metal-salen catalysts were prepared for use in the direct synthesis of diphenyl carbonate (DPC) from phenol and carbon dioxide. We found that metal-salen complexes containing titanium as central metal species retained suitable Lewis acid property for the reaction. It was revealed that the catalytic activity of Ti-salen complexes could be controlled by introducing appropriate substituents into salen ligand. Insertion of phosphonium salts into para-position of aromatic aldehyde of salen ligand enhanced solubility of the catalyst in the methanol-phenol solution, and tert-butyl substituent in the salen ligand induced selective formation of DPC due to steric effect. In addition, introduction of various bridging groups into salen ligand caused change in electronic property of central metal atom. Among the catalysts tested, Ti-(t-butyl)salphen(PPh3) Cl showed the best catalytic performance at 100 °C and 60 bar. The catalytic system utilizing Ti-(t-butyl)salphen(PPh3) Cl catalyst was then optimized by conducting the reaction at various reaction temperatures and pressures.
- Kang, Ki Hyuk,Jun, Jin Oh,Han, Seung Ju,Kwon, Kihyeok,Kwon, O-Sung,Jang, Boknam,Song, In Kyu
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- Ti functionalized hierarchical-pore UiO-66(Zr/Ti) catalyst for the transesterification of phenyl acetate and dimethyl carbonate
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Titanates are frequently used as precursors to prepare transesterification catalysts with TiIV species. Unfortunately, it is challenging to control the dispersity of TiIV active sites on supports. Herein, a series of TiIV species is anchored on abundant linker vacancy sites by introducing point and large scale defects in UiO-66(Zr/Ti) with hierarchical-pore structure. The catalyst functionalized by titanium(iv) oxide bis(2,4-pentanedionate) shows excellent catalytic performance in the transesterification of dimethyl carbonate with phenyl acetate. The catalysts are characterized by XRD, FT-IR, N2 adsorption-desorption, XPS, SEM and STEM-HAADF techniques. The results demonstrate that the delicate mesopores in the support can not only exhibit a large surface area for the distribution of the active sites, but also provide better mass transfer performance. Meanwhile, the introduction of octahedral TiIV ions raises the activity of the catalyst via more coordinatively unsaturated ZrIV sites. Furthermore, using titanium(iv) oxide bis(2,4-pentanedionate) as a Ti source can effectively prevent the condensation of tetrahedral TiIV species anchored on the hierarchical-pore UiO-66(Zr/Ti) support.
- Jia, Bingying,Wu, Miaojiang,Zhang, Hua,Zeng, Yi,Wang, Gongying
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- Gas phase transesterification of dimethylcarbonate and phenol over supported titanium dioxide
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The transesterification of dimethylcarbonate and phenol has been studied in a continuous gas flow reactor at high temperatures which were found to be favorable thermodynamically for high yields of methylphenylcarbonate (MPC). Among various solid catalysts, TiO2/SiO2 showed the highest activity and selectivity for MPC. The structure and the chemical state of titanium species in TiO2/SiO2 have been investigated by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption near edge structure (XANES) of Ti K-edge. It was observed that the titanium species was highly dispersed on silica. Below 10 wt%Ti loading, the titanium phase was not observed by XRD, yet weak XRD peaks of anatase were detected at higher loadings. The Ti K-edge XANES spectra and XPS analyses indicated that Ti(IV) species in the form of a monolayer was dominant below 5 wt% Ti loadings and TiO2 of the anatase structure appeared at higher loadings. The amount of the surface Ti(IV) species measured by XPS increased with Ti loadings and was saturated above 10 wt% in the same manner as the selectivity to MPC changed with Ti loadings. This suggested that surface Ti(IV) species was directly responsible for the selective synthesis of MPC. The crystalline anatase TiO2 was also an active and selective catalyst for the transesterification, yet it contributed to decrease in activity by coking.
- Kim, Won Bae,Lee, Jae Sung
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- Electrosynthesis of diphenyl carbonate catalyzed by Pd2+/0 (in situ NHC) redox catalyst promoted at Au anode
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The effects of Au anodes on electrochemical carbonylation of phenol with CO (1 atm) to diphenyl carbonate (DPC) catalyzed by Pd (in situ NHC) electrocatalyst were studied under galvanostatic electrolysis conditions. Au supported on carbon materials (Au/carbon) were effective anodes for oxidation of the homogeneous Pd electrocatalyst. Various carbon materials, Vulcan XC-72 carbon black (XC72), activate carbon, Ketjenblack, and graphene nanoplatelets (graphene- 1, -2, -3) were tested as a support for Au. The Au/graphene-3 was the most effective anode for DPC formation. Effects of Au loadings and reducing agents (H2 and NaBH4) on the reactivity of the Au/graphene-3 anode for the DPC formation were studied and the materials were characterized using XRD spectroscopy and TEM analysis. These experimental facts indicated that small Au particles on the surface of graphene were superior for the DPC synthesis by the Pd (in situ NHC) electrocatalyst.
- Kanega, Ryoichi,Ogihara, Hitoshi,Yamanaka, Ichiro
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- Nuclear Magnetic Resonance Studies of Iminium Salts. Part 11. Anionic Paticipation of Iminium Salts in Phosgenation Reactions
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Iminium salts act as catalysts in the reaction of phosgene and phenols or thiols to yield chloroformates, which are important synthetic intermediates.This effect is explained in terms of the nucleophilicity of the chloride anion of the salts on the basis of an n.m.r. identification of various intermediates.The mechanism of nucleophilic assistance of iminium salts towards the substrate can be understood as an increase of the nucleophilicity of phenol or thiol by proton abstraction from the OH or SH group by the chloride anion.
- Gauvreau, Jean R.,Martin, Gerard J.,Malfroot, Thierry,Senet, Jean Pierre
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- Highly efficient and stable PbO-ZrO2 catalyst for the disproportionation of methyl phenyl carbonate to synthesize diphenyl carbonate
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Heterogeneous PbO-ZrO2 catalysts (PbZr) were first prepared by coprecipitation method, and used to catalyze the liquid-phase disproportionation reaction of methyl phenyl carbonate (MPC) to synthesize diphenyl carbonate (DPC). PbZr with PbO loading of 15.2 wt% (15.2PbZr) exhibited the best catalytic performance. Under the optimal conditions (200 °C, 2.5 h, and 1.2 g catalyst), the conversion of MPC reached 76.6% and the selectivity of DPC was 99.3%, respectively, which were significantly higher than those of heterogeneous catalysts reported before. The characterization results of XPS, H2-TPR, XRD and BET analyses showed that 15.2PbZr gave the strongest interaction between Pb and Zr, the highest dispersion of PbO as well as the largest surface area and pore volume. Moreover, for 15.2PbZr, though reused for five recycles, the conversion of MPC still reached 75% and the selectivity of DPC was kept at 99.0%, implying that 15.2PbZr represented superior reusability. Besides, the structure of the 15.2PbZr after five times reaction was almost identical to that of the fresh, and Pb was almost not leached out of the catalyst, indicating that the stability of Pb species was improved, due to the existence of favorable interaction between Pb and Zr as well as part of the Pb entering into ZrO2 structure. Thus, 15.2PbZr may serve as a promising catalyst for MPC disproportionation.
- Wang, Songlin,Li, Changgong,Xiao, Zhongliang,Chen, Tong,Wang, Gongying
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- The mechanic study of the Pd-catalyzed synthesis of diphenylcarbonate with heteropolyacid as a cocatalyst
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The reaction to synthesize diphenyl carbonate (DPC) by an oxidative carbonylation of phenol with CO and O2 has been found to proceed through the second-order of phenol concentration. The activation energy E a, Δ S and Δ H are 27.0 kcal mol-1, -6.43 cal mol-1 and 26.3 kcal mol-1, respectively. The kinetic and additive data obtained agree with the proposed mechanism as follows: Pd(OAc)2 reacts with an ammonium phenoxy salt to give AcO-Pd-OPh which then reacts with CO to form AcO-Pd-COOPh. This species leads to PhO-Pd-COOPh which undergoes reductive elimination to give DPC and Pd(0). This Pd(0) is reoxidized to Pd(II) by the help of a heteropolyacid very effectively.
- Hatanaka, Itsuhiro,Mitsuyasu, Naho,Yin, Guochuan,Fujiwara, Yuzo,Kitamura, Tsugio,Kusakabe, Katsumi,Yamaji, Teizo
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- Tellurobromic Acid Diesters; Preparation and Properties
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Title compounds were obtained as reasonably stable to labile oily substances by reacting alkyl carbonochloridates with sodium telluride under phase-transfer conditions at room temperature or in dry n,n-dimethylformamide under ice-cooling.
- Suzuki, Hitomi,Nishioka, Yoshinobu
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- Mesoporous silica-anchored organotin as heterogeneous catalyst for the transesterification of dimethyl carbonate with phenol
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A simple scheme for a mesoporous silica-anchored organotin catalyst was developed for the transesterification of dimethyl carbonate with phenol to diphenyl carbonate. N2-sorption, TEM, UV–Vis, and elemental analysis combined with 29Si and 13C NMR measurements evidenced the formation of mesoporous organic–inorganic hybrid silica with a highly dispersed tetrahedral Sn species. The catalyst exhibited excellent activity and reusability in the transesterification. With a catalyst of 1.0?g, a reaction temperature of 150–180?°C, and a reaction time of 9?h, the phenol conversion and transesterification selectivity reached 51.1 and 99.9?%, respectively. The phenol conversion just decreased from 41.2 to 35.0?% after five runs with 0.5?g of catalyst. The improved stability was attributed to the strong covalent bonding between the organotin and mesoporous silica.
- Zhang, Yuanzhuo,Wang, Songlin,Xiao, Zhongliang,Chen, Tong,Wang, Gongying
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- Highly effective transformation of methyl phenyl carbonate to diphenyl carbonate with recyclable Pb nanocatalyst
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Diphenyl carbonate (DPC) is a type of versatile industrial chemical, and the disproportionation of methyl phenyl carbonate (MPC) is a key step to produce DPC. However, the design and formulation of a catalyst for the efficient synthesis of DPC is a major challenge due to its small equilibrium constant. The support material is a critical factor influencing the performance of Pb nanocatalysts. Thus, a series of Pb-based catalysts over MgO, ZrO2, SiO2, TiO2 and Al2O3 were prepared to investigate the effect of the support materials on the physicochemical properties and catalytic performances for the conversion of MPC to effectively synthesize DPC. The catalysts were well characterized by XRD, BET, TEM, XPS, ICP-OES, H2-TPR, Py-IR and NH3-TPD. The results showed that the nature of the support obviously affected the structural properties and catalytic performances, and Pb was dispersed better on SiO2, TiO2, ZrO2 and MgO than on Al2O3, and showed stronger metal-support interaction over MgO and ZrO2. The activity results revealed that PbO/MgO and PbO/ZrO2 exhibited higher catalytic activities because they contained higher Pb dispersion and more Lewis acid sites, and the catalytic activities followed the order PbO/MgO > PbO/ZrO2 > PbO/SiO2 > PbO/Al2O3 > PbO/TiO2. On the contrary, PbO/MgO and PbO/ZrO2 exhibited better reusability due to strong interaction between the highly dispersed Pb and the supports, and the activity decrease in the case of PbO/SiO2, PbO/Al2O3 and PbO/TiO2 mainly resulted from the Pb leaching loss. This work would contribute to exploiting novel catalytic materials in a wide range of applications for the efficient synthesis of organic carbonates.
- Wang, Songlin,Niu, Hongying,Wang, Jianji,Chen, Tong,Wang, Gongying,Zhang, Jiamin
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- Photo-deposition preparation of supported Pd catalysts for non-phosgene one-step synthesis of diphenyl carbonate
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Pd catalysts anchored on manganese oxide octahedral molecular sieves (OMS-2) were synthesized by photo-deposition method, and then used for one-step oxidative carbonylation of phenol to synthesize diphenyl carbonate (DPC). The results showed that the catalytic activity of Pd/OMS-2 catalyst prepared by photo-deposition was apparently better than those prepared by the traditional precipitation and impregnation method, the distribution of Pd particles was more uniform with the average size of 1.3 nm. This may result from the strong interaction between the carriers and the active Pd species. Irradiated for 5 h at pH 5.0, with the Pd loading of 2.5 wt%, the highest DPC yield of 18.1% was achieved.
- Wu, Changjiang,Yang, Xiaojun,Tian, Qifeng,Bai, Hang,Li, Xiaolu
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- Photo-on-Demand Base-Catalyzed Phosgenation Reactions with Chloroform: Synthesis of Arylcarbonate and Halocarbonate Esters
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Carbonate esters are utilized as solvents and reagents for C1 building blocks in organic synthesis. This study reports a novel photo-on-demand in situ synthesis of carbonate esters with CHCl3 solutions containing a mixture of an aromatic or haloalkyl alcohol having relatively high acidity, and an organic base. We found that the acid-base interaction of the alcohol and base in the CHCl3 solution plays a key role in enabling the photochemical reaction. This reaction allows practical syntheses of diphenyl carbonate derivatives, haloalkyl carbonates, and polycarbonates, which are important chemicals and materials in industry.
- Hashimoto, Yuka,Hosokawa, Sasuga,Liang, Fengying,Suzuki, Yuto,Dai, Namin,Tana, Gegen,Eda, Kazuo,Kakiuchi, Toshifumi,Okazoe, Takashi,Harada, Hidefumi,Tsuda, Akihiko
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- Catalytic performance of metal oxide modified SiMcM-41 catalysts in diphenyl carbonate synthesis
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Decomposition of CCl4 into diphenyl carbonate (DPC) was examined over metal oxides modified SiMCM-41. ZnO/SiMCM-41 and Fe2O 3/SiMCM-41 showed high activity in DPC synthesis. Although many other metal oxides, such as La2O3, CuO, Al2O3 and alkali or alkaline earth oxide, were success in destruction of CCl4, they displayed nearly no activity on DPC synthesis. ZnO/SiMCM-41 and Fe2O3/SiMCM-41 were characterized by X-ray diffraction (XRD), UV-Raman, 29Si MAS NMR and N2 adsorption-desorption isotherms, and results showed that ferric and zinc oxide were supported onto SiMCM-41. The well ZnO dispersion in SiMCM-41 channels and the weak electrostatic interaction between chlorine anion and Zn2+ play an important role for the high activity of ZnO/SiMCM-41 in decomposition of CCl4 into DPC. Pleiades Publishing, Ltd., 2010.
- Su,Li,Cheng,Ren,Yu,Wang
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- A new heterogeneous catalyst for the oxidative carbonylation of phenol to diphenyl carbonate
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Using layered double hydroxides as a support, both the palladium catalyst and the cobalt co-catalyst are heterogenised and proven to form an acceptable catalytic system for the heterogeneous oxidative carbonylation of phenol to diphenyl carbonate (DPC).
- Linsen, Koen J. L.,Libens, Jo,Jacobs, Pierre A.
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- Oxidative carbonylation of phenol with a Pd-O/CeO2-nanotube catalyst
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CeO2 nanotubes (CeO2-NT) were synthesized using carbon nanotubes as template by a liquid phase deposition and hydrothermal method. X-ray diffraction, transmission electron microscopy, and N2 adsorption-desorption were used to characterize the CeO2-NT. The wall of CeO2-NT was composed of small interconnected nanocrystallites ranging from 4 to 9 nm in size. The specific surface area of CeO2-NT was 108.8 m2/g with an outer diameter of 25 nm and length > 300 nm. Supported Pd catalyst, Pd-O/CeO2-NT, was prepared using CeO2-NT as the support. Temperature-programmed reduction analysis showed that the surface oxygen on Pd-O/CeO2-NT could be reduced at low temperature, therefore it showed high activity in the reaction. Pd-O/CeO2-NT was used as the catalyst for the oxidative carbonylation of phenol. It has better activity and DPC selectivity than Pd-O/CeO2-P, which was prepared by supporting Pd on zero dimensional CeO2 particles. Under the optimized conditions, phenol conversion was 67.7% with 93.3% DPC selectivity with Pd-O/CeO2-NT. However, its catalytic activity decreased when the catalyst was used for the second time. This was attributed to the destruction of the tubular structure of Pd-O/CeO2-NT and Pd leaching during the reaction.
- Yuan, Ye,Wang, Zhimiao,An, Hualiang,Xue, Wei,Wang, Yanji
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- Oxidative carbonylation of phenol
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Oxidative carbonylation of phenol was studied. The activities of the catalysts and cocatalysts were compared. The effect of solvents and pressure on the yield of the target product was studied.
- Lapidus,Pirozhkov,Sukhov
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- Tuning of oxygen species and active Pd2+ species of supported catalysts via morphology and Mn doping in oxidative carbonylation of phenol
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A series of nanocubes and nanorods of CeO2 and MnxCeyO (x,y = 1 or 3) oxides were prepared by the hydrothermal method. Samples as prepared were characterized by Transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy, in order to gain a fundamental understanding of the effects of the morphology and Mn dopant on the oxygen species and active Pd2+ species in the oxidative carbonylation of phenol using Pd catalysts supported on as-prepared oxides. Although the oxygen species on supports with different morphologies varied, the catalytic performance in the oxidative carbonylation reaction did not show the significant change. Comparatively speaking, the doping of Mn is a more efficient method to control active oxygen species. It is deduced that Pd and Mn are “dopants” for pure CeO2, both of which improve the formation of oxygen vacancies that help to mitigate the reduction of active Pd species due to the strong interaction between the Pd2+ and the MnxCeyO support. Furthermore, we propose that Oβ (hydroxyl oxygen, chemisorbed oxygen or the oxygen vacancy) species acted as intermediates to lower the reduction of active palladium species by the strong interaction between the noble metal and supports, while the lattice oxygen Oα were involved in the redox cycle of Pd0/Pd2+ in the oxidative carbonylation of phenol to diphenyl carbonate. All results suggest that Mn dopants play a more important role in the activity than morphology does.
- Yang, Xiaojun,Hu, Yue,Bai, Hang,Feng, Maoqi,Yan, Zhiguo,Cao, Shuo,Yang, Bin
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- An active and heterogeneous catalyst for synthesis of diphenyl carbonate
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Zn4O[(O2C)-C6H4-(CO2)]3 was prepared by solvothermal method and characterized with XRD and FT-IR. Zn4O[(O2C)-C6H4-(CO2)]3 was used as the catalyst for the synthesis of diphenyl carbonate via the transesterification dimethyl carbonate and phenol and its catalytic activity was compared with Ti(OBu)4, Mg-Al Mg-Al LDH and Zn-Al Mg-Al LDH. The results show that Zn4O[(O2C)-C6H4-(CO2)]3 is an active and heterogeneous catalyst for the synthesis of diphenyl carbonate via the transesterification.
- Wang, Liping,Wang, Gongying,Wang, Fan
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- Transesterification of dimethyl carbonate and phenol to diphenyl carbonate with the bismuth compounds
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Bismuth oxide was first employed for the transesterification of dimethyl carbonate with phenol to diphenyl carbonate, which has excellent catalytic activity. With 0.4?g Bi2O3, the phenol conversion of 46.4% and transesterification selectivity of 99.9% were attained. The characterization of the used sample by XRD, FTIR and solid-state 13C-NMR indicate that a new compound of bismuth phenoxide was formed with the disappearance of bismuth oxide. It was evidenced that the bismuth phenoxide act as the role of active phase in the transesterification, which was generated facilely in situ by the reaction of bismuth oxide added with the raw material of phenol. The bismuth phenoxide presents excellent reusability, after four consecutive runs, the phenol conversion remained above 45%, and the transesterification selectivity was maintained at 99.9%.
- Xiao, Zhongliang,Yang, Hao,Zhang, Hua,Chen, Tong,Wang, Gongying
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- Preparation and application of coconut shell activated carbon immobilized palladium complexes
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Coconut shell activated carbon (CSAC) granules were used as carriers to immobilize palladium complexes. Boehm titration showed that the hydroxyl content of the carbon surface reached 0.376 mmol g-1 after 20% HNO 3 treatment. Ethylenediamine, benzyl malononitrile and propyl malononitrile were successfully grafted onto the oxidized CSAC. The bidentate nitrogen ligands complexed Pd2+ samples were characterized by FT-IR, XPS, ICP and N2 adsorption-desorption. In oxidative carbonylation of phenol, three bidentate ligand grafted catalysts were evaluated in a high pressure reaction vessel. The results showed that the ethylenediamine grafted catalyst had a phenol conversion of 12.06% and a diphenyl carbonate (DPC) selectivity of 91.03%. In comparison, the benzyl malononitrile grafted catalyst displayed a phenol conversion of 12.00% and a DPC selectivity of 90.65%. The propyl malononitrile grafted catalyst displayed a phenol conversion of 6.22% and a DPC selectivity of 81.02%. Additionally, the ethylenediamine and the benzyl malononitrile grafted catalysts were also investigated in a continuous packed-bed reactor. The results showed that the phenol conversion and the DPC selectivity were comparative to those obtained in a high pressure reaction vessel. This journal is the Partner Organisations 2014.
- Zhang, Yulian,Xiang, Shuanglong,Wang, Guoqing,Jiang, Hong,Xiong, Chunrong
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- Direct synthesis of diphenyl carbonate by electrocarbonylation at a Pd 2+-supported anode
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The first electrochemical synthesis of diphenyl carbonate was accomplished using triethylamine/tetrabutylammonium perchlorate/phenol/dichloromethane or sodium phenoxide/phenol/acetonitrile electrolyte at a [PdCl2/ activated carbon and vapor grown carbon fiber] anode, 1 atm CO and 25°C. Sodium phenoxide functioned as a promoter, triethylamine, and a supporting electrolyte, tetrabutylammonium Perchlorate, for the carbonylation.
- Murayama, Toru,Arai, Yuji,Hayashi, Tomohiko,Yamanaka, Ichiro
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- The reactions of difluorodiiodomethane with nucleophiles
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Treatment of difluorodiiodomethane with phenoxides (ArO-) in DMF at room temperature gives ArOCF2I in 7-15%, the carbonates (ArOCO2Ar) being the major products, while with thiophenoxides affords difluoromethylene derivativ
- Guo, Yong,Chen, Qing-Yun
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- Deactivation causes of supported palladium catalysts for the oxidative carbonylation of phenol
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Palladium catalysts supported on manganese oxides octahedral molecular sieves (OMS-2), Pb doped OMS-2 (Pb-OMS-2) and perovskite-type La0.5Pb0.5MnO3 were prepared for investigating the deactivation causes of catalysts during the oxidative carbonylation of phenol. The catalytic experiments on three different sets of catalysts demonstrated that they were inactive after continuous reaction for 22?h. XRD patterns and HRTEM images demonstrated that carbonaceous pollution and palladium leaching occurred during the reaction process. The solvent and oxygen have significant impact on the palladium leaching by ICP-AES analysis. In addition, hot filtration tests and SH-HZSM-5 adsorption studies indicated that the leached palladium species are not active species. The results of XPS patterns and H2-TPR profiles showed that aggregation and reduction of Pd species was another deactivation cause. It was discovered that lattice oxygen species decreased and palladium aggregated, which hindered the re-oxidation of Pd(0) to Pd(II). In summary, carbonaceous pollution, Pd leaching, aggregation and consumption of oxygen species hindered the redox recycling of palladium, which resulted in the deactivation of supported palladium catalysts for the oxidative carbonylation of phenol.
- Yin, Chaofan,Zhou, Jie,Chen, Qiming,Han, Jinyu,Wu, Yuanxin,Yang, Xiaojun
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- Synthesis of diphenyl carbonate from CO2, phenoxide, and CCl4 with ZnCl2 as catalyst
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Direct synthesis of diphenyl carbonate (DPC) from phenoxide, CO2 and CCl4 in one pot was realized with ZnCl2 as catalyst. Trichloromethyl cation may act on potassium phenyl carbonate, which brings the carbonyl more easily attached on by the phenoxide. Onium salts promote the reaction greatly, especially with phenol and potassium carbonate instead of phenoxide as reactants. Moreover, the substituent on the aromatic ring has significant effects on the selectivity and yield of carbonate. Copyright
- Li, Zhenhuan,Qin, Zhangfeng,Zhu, Huaqing,Wang, Jianguo
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- Alkyl and aryl 4,5-dichloro-6-oxopyridazin-1(6 H)-carboxylates: A practical alternative to chloroformates for the synthesis of symmetric and asymmetric carbonates
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Symmetric and asymmetric carbonates were synthesized by using alkyl or aryl 4,5-dichloro-6-oxopyridazin-1(6H)-carboxylates. Five aryl 4,5-dichloro-6-oxopyridazin-1(6H)-carboxylates were converted into the corresponding diaryl carbonates in good to excellent yields by treatment with potassium carbonate in refluxing THF. When the 4,5-dichloro-6-oxopyridazin-1(6H)-carboxylates were treated with aliphatic or aromatic alcohols in the presence of potassium tert-butoxide in toluene at room temperature, they gave the corresponding symmetric or asymmetric carbonates in moderate to excellent yields. Alkyl and aryl 4,5-dichloro-6-oxopyridazin-1(6H)-carboxylates are therefore efficient, stable, and ecofriendly alternatives to chloroformates.
- Moon, Hyun Kyung,Sung, Gi Hyeon,Yoon, Yong-Jin,Yoon, Hyo Jae
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- THE PREPARATION OF FLUOROARENES BY THE CATALYTIC DECARBOXYLATION OF ARYL FLUOROFORMATES
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The catalytic decarboxylation of phenyl fluoroformate to fluorobenzene has been achieved with yields of 70-80percent in a flow system using alumina or alumina-based catalysts.The reaction occurs in short space times (Pd/Al2O3>Rh/Al2O3 ca.Al2O3. 2,4,6-Trimethylphenyl fluoroformate, a new material, was found to decarboxylate similarly to give 1-fluoro-2,4,6-trimethylbenzene, but 4-chlorophenyl fluoroformate was noted to produce only low yields (ca. 10percent) of the corresponding aryl fluoride.
- Ashton, David P.,Ryan, Anthony T.,Webster, Brian R.,Wolfindale, Brett A.
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- THE PALLADIUM-CATALYZED SYNTHESIS OF DIPHENYL CARBONATE FROM PHENOL, CARBON MONOXIDE, AND OXYGEN
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Diphenyl carbonate was obtained from the reaction of carbon monoxide, phenol, and oxygen using catalytic quantities of palladium, a tertiary amine, and an oxidation cocatalyst at room temperature and atmospheric pressure.A variety of copper, vanadium, cobalt, and manganese salts were effective cocatalysts, although in many cases side products were produced.Using catalytic quantities of manganese salts, up to 100 mol of diphenylcarbonate per mol palladium was realized.
- Hallgren, J.E.,Lucas, G.M.,Matthews, R.O.
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- Effects of Pb dopant on structure and activity of Pd/K-OMS-2 catalysts for heterogeneous oxidative carbonylation of phenol
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Palladium catalysts supported on Pb-cation-doped manganese oxide octahedral molecular sieves were prepared and used for heterogeneous oxidative carbonylation of phenol to diphenyl carbonate in the absence of homogeneous cocatalysts. The synthesized catalysts were characterized by ICP-AES, XRD and XPS techniques. The experimental results demonstrated that an enhanced activity was obtained when Pb2+ entered into the tunnels of cryptomelane by replacing K+ to form a new hollandite-type phase of Pb2-xMn8O16. The promotion effect of Pb dopant on activity was ascribed to the increase of low-valence Mn3+ and OH group, which was favor of reoxidation of Pd0 to active Pd2+ species.
- Yang, Xiaojun,Han, Jinyu,Du, Zhiping,Yuan, Hua,Jin, Fang,Wu, Yuanxin
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- Influence of coordination groups on the catalytic performances of organo-titanium compounds for disproportionation of methyl phenyl carbonate to synthesize diphenyl carbonate
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The disproportionation of methyl phenyl carbonate (MPC) to synthesize diphenyl carbonate (DPC) catalyzed by organo-titanium compounds with different coordination groups was systematically investigated. The results of the molecular structure analysis, the catalytic performance evaluation and the chemical computational studies revealed that both the electron effect and steric hindrance of the coordination groups together affected the active Ti center and therefore influenced the catalytic performance of the catalysts. The influence of the electron effect was more important than the steric hindrance. The catalytic activity is in the order of Ti(O-iC3H7)4?>?Ti(OC6H5)4?>?Ti(OC4H9)4?>?TiO(OOCCH3)2?>?TiO(acac)2?>?Cp2TiCl2, and Ti(O-iC3H7)4 exhibited the best catalytic performance, due to its appropriate steric hindrance and electron effect for the coordination group. Under the optimum condition (n(Cat.)/n(MPC)?=?0.04, reacted at 180?°C for 3?h), the MPC conversion of 90.4% and DPC selectivity of 99.6% were attained, respectively, which are comparable to those of other catalysts reported. Moreover, the catalyst is low cost, non-toxic and easily obtained by readily commercial-available purchase, and this catalytic system is also easy operation and convenient-controllable, indicating that it is conducive to future industrial application. In addition, a possible reaction mechanism catalyzed by the organo-titanium compounds with Lewis acid was also proposed for the process.
- Wang, Songlin,Chen, Tong,Wang, Gongying,Cui, Chengxing,Niu, Hongying,Li, Changgong
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- Preparation and catalytic property of MoO3/SiO2 for disproportionation of methyl phenyl carbonate to diphenyl carbonate
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MoO3/SiO2 were prepared by different methods and used as heterogeneous catalysts for the liquid-phase disproportionation of methyl phenyl carbonate (MPC) to diphenyl carbonate (DPC). The characterization of XRD, FT-IR and BET showed that the preparation methods remarkably affected the structural properties and catalytic activities of MoO3/SiO2. The MoO3/SiO2 prepared by a combined method of sol-gel and hydrothermal treatment (M-SGH) exhibited the highest catalytic activity, since high dispersion of MoO3, big specific surface area and large pores were obtained. Under the optimal conditions (200 °C, 2 h, using 0.9 g catalyst with a MoO3 loading of 15 wt%), the conversion of MPC reached 72.8% and the yield of DPC was 71.4%. Moreover, M-SGH showed excellent reusability and regeneration. After seven consecutive runs, the conversion of MPC decreased slightly from 72.8% to 56%. The formation of carbonate species on the catalyst surface was the main reason for the decrease of activity. The deactivated M-SGH could be facilely regenerated by calcination at 500 °C in air, and the catalytic activity of regenerated M-SGH was completely recovered to the same with that of fresh.
- Wang, Songlin,Zhang, Yuanzhuo,Chen, Tong,Wang, Gongying
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- Double- and triple-consecutive O-insertion into tert-butyl and triarylmethyl structures
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(Matrix Presented) The concecutive Criegee rearrangement reactions were studied for tert-butyl trifluoroacetate, triarylcarbinols, and benzophenone ketales with trifluoroperacetic acid (TFPAA) in trifluoroacetic acid (TFA). The formation of methyl acetate and methyl trifluoroacetate indicates that the consecutive double-O-insertion process has taken place for tert-butyl trifluoroacetate. The intermediate dimethoxymethylcarbonium ion was detected below 5°C. A consecutive triple-O-insertion process has been observed for triarylmethanols and benzophenone ketals. A new high yield method of corresponding diaryl carbonates synthesis was developed.
- Krasutsky, Pavel A.,Kolomitsyn, Igor V.,Krasutsky, Sergiy G.,Kiprof, Paul
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- Preparation and catalytic property of Pb-Zr mixed oxides for methyl phenyl carbonate disproportionation to synthesize diphenyl carbonate
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Pb-Zr mixed oxides with 15.2 wt% PbO loading were prepared by four different preparation processes, and their catalytic performances for the disproportionation of methyl phenyl carbonate (MPC) to synthesize diphenyl carbonate (DPC) were evaluated. Physicochemical characterizations including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), BET surface area measurement, H2-temperature programmed reduction (H2-TPR), ammonia temperature programmed desorption (NH3-TPD) and infrared spectroscopy of pyridine adsorption (Py-IR), as well as catalytic tests of MPC disproportionation reaction showed that catalyst preparation process exerted significant influence on the composition, structural property, catalytic performance of obtained catalysts, and the catalyst prepared by co-precipitation method (PbZr-CP) demonstrated better dispersion of active phase, larger specific surface area and more Lewis acid sites on the surface due to the strong interaction of Pb and Zr, and thus exhibited higher catalytic activity than those prepared by other processes.
- Wang, Songlin,Niu, Hongying,Wang, Jianji,Chen, Tong,Wang, Gongying
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- Transesterification of phenol and dimethyl carbonate catalyzed by titanium oxide acetylacetonate catalyst
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Titanium oxide acetylacetonate (TiO(acac)2) was found to be a novel and efficient heterogeneous catalyst for the transesterification of phenol and dimethyl carbonate (DMC) to diphenyl carbonate (DPC). The conversion of phenol was 45.8% on the TiO(acac)2 pretreated at 180 °C, and the turnover number reached 96, which was better than the more common organic titanium catalyst. The effect of the amount of catalyst on the catalytic performance was investigated. The transesterification selectivity decreased with catalyst loadings over 0.2 g per 100 ml reactants. At the optimized amount of catalyst the conversion of phenol was 42.4%, and no anisole was detected. In particular, the TiO(acac)2 catalyst proved reusable, and catalytic activity of the recovered TiO(acac)2 was almost the same as that of the fresh catalyst. The conversion of phenol 40.0% was attained from TiO(acac)2 recovered for the fifth time.
- Li, Bijing,Tang, Rongzhi,Chen, Tong,Wang, Gongying
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- Synthesis of diphenyl carbonate from carbon dioxide, phenol, and carbon tetrachloride catalysed by ZnCl2 using trifluoromethanesulfonic acid as functional co-catalyst
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Diphenyl carbonate (DPC) was synthesised from carbon dioxide, phenol, and carbon tetrachloride catalysed by the Lewis acid ZnCl2 with the addition of co-catalyst. It was found that common bases are not effective co-catalysts for the production of DPC, and only slight enhancement in the catalytic activity of ZnCl2 was observed in the presence of inorganic additives such as inorganic carbonates and quaternary ammonium salts. Although poor conversion of phenol and yield of DPC were obtained using ZnCl2 or trifluoromethanesulfonic acid (CF3SO3H) as the sole catalyst, the catalytic activity of ZnCl2 was significantly improved by the addition of a catalytic amount of CF3SO3H. CF 3SO3H has been proven to be an effective co-catalyst. The conversion of phenol and the yield of DPC were dependent on the amount of ZnCl2 and CF3SO3H, the reaction temperature, and the pressure of CO2. A possible reaction mechanism for the synthesis of DPC catalysed by the co-catalytic system including ZnCl2 and CF3SO3H was also proposed.
- Fan, Guozhi,Wang, Min,Duan, Zhenxiao,Wan, Minghai,Fang, Tao
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- Efficient synthesis of diphenyl carbonate from dibutyl carbonate and phenol using square-shaped Zn-Ti-O nanoplates as solid acid catalysts
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Square-shaped Zn/Ti oxides were prepared by a co-precipitation method and used for the synthesis of diphenyl carbonate (DPC) via transesterification of dibutyl carbonate (DBC) with phenol. The results showed that a 51% yield of butyl phenyl carbonate (BPC) and 13% yield of DPC could be achieved at 205 °C in the presence of 3ZnTi-400 (Zn : Ti molar ratio 3 : 1). Moreover, it is found that 3ZnTi-400 was also an active catalyst for the disproportionation of BPC to DPC, and 80% conversion of BPC was obtained at 190 °C. The prepared catalysts could be reused for three runs of the transesterification without noticeable deactivation. The catalysts were characterized by XRD, SEM, XPS, and TPD with the aim of establishing the relationship between catalytic performance and structure.
- Wang, Peixue,Liu, Shimin,Zhou, Feng,Yang, Benqun,Alshammari, Ahmad S.,Deng, Youquan
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- Cyanoesterification of norbornenes catalyzed by palladium: facile synthetic methodology to introduce cyano and ester functionalities via direct carbon-carbon bond cleavage of cyanoformates
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Addition of cyanoformates (NC-COOR) to norbornene at 110 °C in the presence of Pd(PPh3)4 (10 mol %) as a catalyst affords with high selectivity the corresponding doubly functionalized polar norbornane derivatives bearing both cyano and ester groups. By using benzonorbornadiene and norbornadienes as the substrates, the reaction can be extended to synthesis of various functionalized norbornene derivatives in moderate to excellent yields. In most cases alkyl groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, tert-butyl, and benzyl in the ester functionalities are applicable to the reactions. Oxidative addition of cyanoformates to Pd(0), insertion of norbornenes, and reductive elimination of the corresponding adducts constitute the proposed catalysis pathway.
- Nishihara, Yasushi,Inoue, Yoshiaki,Izawa, Seisuke,Miyasaka, Mitsuru,Tanemura, Kenki,Nakajima, Kiyohiko,Takagi, Kentaro
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- ZnBr2 supported on silica-coated magnetic nanoparticles of Fe3O4 for conversion of CO2 to diphenyl carbonate
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A magnetic Fe3O4@SiO2-ZnBr2 catalyst was prepared by supporting ZnBr2 on silica-coated magnetic nanoparticles of Fe3O4 and used as a recoverable catalyst for the direct synthesis of diphenyl carbonate (DPC) from CO2 and phenol in the presence of carbon tetrachloride. The as-prepared catalyst was characterized by infrared spectroscopy (IR), powder X-ray diffraction (XRD), a X-ray photoelectron spectrometer (XPS) and BET. Zn loading in the supported catalyst and leaching during the reaction process were determined by atomic absorption spectroscopy (AAS). It was found that Fe3O4@SiO2-ZnBr2 showed higher catalytic activity than homogenous ZnCl2 and ZnI2 as well as homogenous ZnBr2. With this new catalyst under optimized conditions, a yield of DPC at 28.1% was obtained. The heterogeneous catalyst Fe3O4@SiO2-ZnBr2 can also be recovered by a permanent magnet after the reaction and reused up to 4 times without noticeable deactivation.
- Fan, Guozhi,Luo, Shanshan,Wu, Qiang,Fang, Tao,Li, Jianfen,Song, Guangsen
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- Effect of metal oxide composite method on catalytic oxidation performance of aerogel supported Pd catalysts in oxidative carbonylation
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A series of metal manganese-cerium silicon composite aerogel supported Pd catalysts were prepared by the in-situ method, the precipitation method and the impregnation method. The catalysts were applied to synthesize diphenyl carbonate (DPC) by oxidative carbonylation. The effects of different preparation methods and composite metal oxide contents on catalytic activities were studied. The prepared catalysts were characterized by XRD, FTIR, BET, TEM, H2-TPR and XPS. The results showed that the metal composite method had a great influence on the catalyst particle size and specific surface area; the low temperature oxidation performance and surface oxygen species content of the catalysts prepared by different methods were different. The catalyst prepared by the impregnation method has a large specific surface area and particle size, good low-temperature oxidation performance and more surface adsorption oxygen, which helps to improve the multi-step electron transfer efficiency, to promote the regeneration of the active component Pd2+ and to increase catalytic activity.
- Cheng, Ping,Hong, Chao,Huang, Yuhai,Peng, Meng,Yuan, Hua
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- A new efficient Pd-catalyzed synthesis of diphenyl carbonate with heteropolyacid as a cocatalyst
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A new catalytic system, Pd-Mn-HPA (heteropolyacid), has been found to be very efficient in the oxidative carbonylation of phenol to diphenyl carbonate (DPC) with CO and oxygen at low pressure in the absence of solvent. Synergistic effect between W-Mo-heteropolyacid and Mn(OAc)2 was observed for regenerating the Pd(II) species from Pd(0). The ratio of W-Mo in heteropolyacid, efficiency of the heteropolyacid salts and the roles of tetrabutylammonium bromide and molecular sieves have been investigated in detail. Using suitable components of the catalyst system, 53% yield of DPC with a Pd turnover number of 827 can be attained.
- Yin, Guochuan,Jia, Chengguo,Kitamura, Tsugio,Yamaji, Teizo,Fujiwara, Yuzo
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- Pd catalyst supported on CeO2 nanotubes with enhanced structural stability toward oxidative carbonylation of phenol
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Ordered CeO2 nanotubes (CeO2-T) were prepared via a hydrothermal synthesis process using the triblock copolymer polyethylene oxide-polypropylene oxide-polyethylene oxide (P123) as a morphology control agent. CeO2-T characterization demonstrated the formation of single crystal structures having lengths between 1-3 μm and diameters 2-T) was also prepared through hydrothermal means. H2-temperature reduction profile and Raman spectroscopy analyses showed that the oxygen vacancies on the CeO2 surface increased and the reduction temperature of the surface oxygen decreased after Pd loading onto CeO2-T. Pd/CeO2-T was employed as a catalyst toward the oxidative carbonylation of phenol and the reaction conditions were optimized. Phenol conversion was 53.2% with 96.7% selectivity to diphenyl carbonate under optimal conditions. The integrity of the tubular CeO2 structure was maintained after the catalyst was recycled, however, both activity and selectivity significantly decreased, which was mainly attributed to the Pd active component significantly leaching during the reaction.
- Fu, Zengjie,Wang, Zhimiao,Wang, Hongjuan,Li, Fang,Xue, Wei,Wang, Yanji
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- Pd(NHC) electrocatalysis for phosgene-free synthesis of diphenyl carbonate
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Electrocarbonylation of phenol with CO to diphenyl carbonate was studied using a homogeneous Pd electrocatalyst. Various ligands were screened, and N-heterocyclic carbene (NHC) groups, such as 1,3-dimesitylimidazol-2-ylidene, were found to be effective for the electrocarbonylation. An in situ-generated NHC derived from a 1,3-dialkylimidazolium chloride was also effective for the electrocarbonylation, and 1,3-di(tert-butyl)imidazoline chloride was the most effective NHC precursor, with a stronger electron-donating ability to PdCl 2(MeCN)2 electrocatalyst.
- Kanega, Ryoichi,Hayashi, Tomohiko,Yamanaka, Ichiro
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- Ionic composite of palladium(II)/iron bis(dicarbollide) for catalytic oxidative carbonylation in the formation of diphenyl carbonate
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The carborane-based sandwich iron complex, [n-Bu4N]{Fe(3,3′)-[1,2-(PPh2)2-1,2-C2B9H9]2}, was synthesized in 53.1% yield. A catalyst composite of PdAc2/[n-Bu4N]{Fe(3,3′)-[1,2-(PPh2)2-1,2-C2B9H9]2} was found to be highly active for the oxidative carbonylation of phenol, with the formation of diphenyl carbonate (DPC). A DPC yield of 46% and a turnover number (TON) of 511 were achieved in 4 h using the composite at 110 °C. For comparison, the reaction was also investigated using catalyst composites of PdAc2/Mn(acac)3, PdAc2/Fe(acac)3, PdAc2/Co(acac)3 and PdAc2/Ce(acac)3 (acac = acetylacetone) under the same conditions of temperature and pressure. The DPC yield was determined by gas chromatography with flame ionization detector (GC-FID). All new products were characterized by elemental analysis, and by 1H, 13C, 11B and 31P NMR and FT-IR spectroscopy.
- Biying, Algin Oh,Yuanting, Karen Tang,Hosmane, Narayan S.,Zhu, Yinghuai
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- Effect of zirconia polymorph on the synthesis of diphenyl carbonate over supported lead catalysts
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Zirconia supported Pb-based catalysts with purely tetragonal/monoclinic crystals were prepared and analyzed well by XRD, TEM-EDS, XPS, H2-TPR, BET, Py-IR and NH3-TPD techniques. The results indicate that zirconia polymorph has great effect on their structure and catalytic property for the synthesis of diphenyl carbonate (DPC) through methyl phenyl carbonate (MPC) disproportionation due to the differences of surface chemical properties, and tetragonal zirconia supported lead catalyst (TZ-Pb) shows bigger dispersion degree of PbO, higher surface area and Lewis acid amounts and thereby exhibits higher catalytic activity and selectivity compared to monoclinic zirconia supported catalyst (MZ-Pb). Furthermore, TZ-Pb shows better reusability due to strong metal-support interaction and may be readily recycled for at least four times without remarkable reactivity loss. This work provides a prospective reference for the facile and efficient synthesis of zirconia polymorph materials in various catalysis applications.
- Wang, Songlin,Niu, Hongying,Guo, Mengjun,Wang, Jianji,Chen, Tong,Wang, Gongying
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- Direct synthesis of diphenyl carbonate by mediated electrocarbonylation of phenol at Pd2+-supported activated carbon anode
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Mediated electrocarbonylation of phenol to diphenyl carbonate (DPC) at a PdCl2-supported activated carbon anode in 1 atm CO at 298 K was studied. A dry CH2Cl2 or CH3CN solvent and a galvanostatic electrolysis of 1 mA were necessary for formation of DPC, while the addition of a base and a supporting electrolyte was also essential. A combination of triethylamine (Et3N) and tetrabutylammonium perchlorate (Bu4NClO4) was suitable in various combinations. The addition of 2 equiv. of Et3N to the electrolyte (C6H5OH/Bu4NClO4/CH 2Cl2) at 1-h intervals was more efficient in the formation of DPC than a single initial addition of the same amount of Et3N. The yield of DPC was 130% based on Pd and its current efficiency (CE) was 42% for 6 h. The CE of the CO2 formation was only 3%. Sodium phenoxide (PhONa) showed dual functionality as a base and supporting electrolyte. When the mediated electrocarbonylation was conducted in a C6H 5OH/PhONa/CH3CN electrolyte, DPC was produced in 172% yield and 40% CE for 6 h. The CE of the CO2 formation was 10%. DPC formed continuously after a single initial addition of 4 equiv. of PhONa. Li or K phenoxide also worked as promoters for the mediated electrocarbonylation of phenol to DPC.
- Murayama, Toru,Hayashi, Tomohiko,Arai, Yuji,Yamanaka, Ichiro
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- Light-induced synthesis of unsymmetrical organic carbonates from alcohols, methanol and CO2under ambient conditions
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The present work describes the first visible light-assisted, metal-free and organic base 1,1,3,3-tetramethyl guanidine (TMG) mediated synthesis of unsymmetrical methyl aryl/alkyl carbonates from the reaction of alcohols, methanol, and CO2 in high to excel
- Saini, Sandhya,Gour, Nand Kishor,Khan, Shafiur Rehman,Deka, Ramesh Chandra,Jain, Suman L.
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supporting information
p. 12800 - 12803
(2021/12/13)
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- Diphenyl carbonate compound preparation method
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The invention relates to the field of diphenyl carbonate synthesis, and discloses a diphenyl carbonate compound preparation method, which comprises: in the presence of a catalyst represented by a formula (1-1) or a formula (1-2), carrying out a transesterification reaction on a phenol compound represented by a formula (II) and a diester carbonate compound represented by a formula (III), wherein R1, R2 and R3 are selected from a C1-C14 aliphatic hydrocarbon group, a C3-C14 cycloalkyl group, a C6-C14 aryl group, a C7-C14 alkylaryl group, a C7-C14 aralkyl group and a C10-C14 condensed ring aryl group, and X is halogen. The method is high in catalytic activity, high in selectivity and good in stability. Formula (1-1) is (H-[O-Si-(R1)2]n-O)x1-Ti-(OR3)y1X(4-x1-y1), and formula (1-2) is [Si(R2)xO]x2-Ti-(OR3)y2X(4-x2-y2).
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Paragraph 0110; 0111; 0119-0139
(2020/04/01)
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- Catalyst for preparing diphenyl carbonate compound, preparation method and applications thereof
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The invention relates to the field of diphenyl carbonate compound synthesis, and discloses a catalyst for preparing a diphenyl carbonate compound, a preparation method and applications thereof, wherein the catalyst is represented by a formula (1-1) or a formula (1-2), R1, R2 and R3 are selected from C1-C14 aliphatic hydrocarbon groups, C3-C14 cycloalkyl groups, C6-C14 aryl groups, C7-C14 alkaryl groups, C7-C14 aralkyl groups and C10-C14 condensed ring aryl groups, and X is halogen. The catalyst used in the method has high catalytic activity, high selectivity and good stability in a reaction for preparing diphenyl carbonate through a transesterification method. The formula (1-1) is (H-[O-Si-(R1)2]n-O)x1-Ti-(OR3)y1X(4-x1-y1), and the formula (1-2) is [Si(R2)xO]x2-Ti-(OR3)y2X(4-x2-y2).
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Paragraph 0119-0121
(2020/04/01)
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- CARBONATE DERIVATIVE PRODUCTION METHOD
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The objective of the present invention is to provide a method for producing a carbonate derivative in a safe and efficient manner. The method for producing a carbonate derivative according to the present invention is characterized in comprising irradiating light on a composition containing a C1-4 halogenated hydrocarbon having one or more kinds of halogen atoms selected from the group consisting of a chlorine atom, a bromine atom and an iodine atom, a nucleophilic functional group-containing compound and the specific base in the presence of oxygen.
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Paragraph 0099-0100; 0102-0104; 0109-0110
(2020/04/09)
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- ISOCYANATE PRODUCTION METHOD
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An isocyanate production method is characterized by having: a carbamation step in which a carbonic acid ester, an inorganic acid salt of an amino acid derivative, and a basic compound are reacted to obtain a reaction mixture containing a carbamic acid ester derived from the carbonic acid ester, a hydroxy compound derived from the carbonic acid ester, and the carbonic acid ester; and a thermal decomposition step in which the carbamic acid ester is subjected to a thermal decomposition reaction to obtain an isocyanate.
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Paragraph 0202; 0208-0213
(2020/07/23)
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- Rhodium-Catalyzed Carbonylative Synthesis of Aryl Salicylates from Unactivated Phenols
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A rhodium-catalyzed carbonylative transformation of unactivated phenols to aryl salicylates is described. This protocol is characterized by utilizing 1,3-rhodium migration as the key step to provide direct access to synthesize ohydroxyaryl esters. Various desired aryl o-hydroxybenzoates were produced in moderate to excellent yields with bis(dicyclohexylphosphino)ethane (DCPE) as the ligand. Interestingly, diphenyl carbonate was formed as the main product when 1,3-bis(diphenylphosphino)propane (DPPP) was used as the ligand. A plausible reaction mechanism is proposed.
- Ai, Han-Jun,Zhang, Youcan,Zhao, Fengqian,Wu, Xiao-Feng
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supporting information
p. 6050 - 6054
(2020/10/02)
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- Method for preparing diphenyl carbonate through interesterification
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The invention relates to a method for preparing diphenyl carbonate through interesterification of dimethyl carbonate and phenol. The problem of low activity of heterogeneous catalysts in the prior artis mainly solved. A catalyst is a titanium oxide system with high proportion exposure of a (001) crystal surface modified by a composite oxide. According to the technical scheme, catalyst activity and selectivity are improved effectively, the problem of low catalyst activity in a reaction of synthesis of the diphenyl carbonate through interesterification of the phenol and the dimethyl carbonate is well solved, and the method can be used for industrial production of the diphenyl carbonate.
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Paragraph 0053-0057
(2019/05/08)
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- Method for preparing diphenyl carbonate through phenol ester exchange
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The invention relates to a method for preparing diphenyl carbonate through dimethyl carbonate and phenol ester exchange reaction. The method mainly solves the problem of low activity of a heterogeneous catalyst in the prior art. A catalyst used in the method is titanium oxide with a (001) crystal face exposed at a high ratio. By means of the technical scheme, the activity and selectivity of the catalyst are effectively improved, the problem of low activity of the catalyst in the reaction of synthesizing the diphenyl carbonate through phenol and dimethyl carbonate ester exchange is well solved,and the method can be used for industrial production of the diphenyl carbonate.
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Paragraph 0048-0053
(2019/05/08)
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- Concise and Additive-Free Click Reactions between Amines and CF3SO3CF3
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Trifluoromethyl trifluoromethanesulfonate has proved to be an excellent reservoir of difluorophosgene and a promising click ligation for amines in the preparation of urea derivatives, heterocycles, and carbamoyl fluorides under metal- and additive-free conditions. The reactions are rapid, efficient, selective, and versatile, and can be performed in benign solvents, giving products in excellent yields with minimal efforts for purification. The characteristics of the reactions meet the requirements of a click reaction. The use of trifluoromethyl trifluoromethanesulfonate as a click reagent is advantageous over other “CO” sources (e.g., TsOCF3, PhCO2CF3, CsOCF3, AgOCF3, and triphosgene) because this reagent is readily accessible; easy to scale up; and highly reactive, even under metal- and additive-free conditions. It is anticipated that CF3SO3CF3 will be increasingly as important as SO2F2 as a click agent in future drug design and development.
- Song, Hai-Xia,Han, Zhou-Zhou,Zhang, Cheng-Pan
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supporting information
p. 10907 - 10912
(2019/08/02)
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- Diphenyl carbonate compound preparation method
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The present invention relates to the field of diphenyl carbonate compounds, and discloses a preparation method of a diphenyl carbonate compound represented by a formula (I), wherein the preparation method comprises: carrying out a transesterification reaction on a phenyl acetate compound represented by a formula (II) and a carbonic acid diester compound represented by a formula (III) in the presence of a catalyst, the catalyst contains 1,4-diazabicyclo[2.2.2]octane, R is hydrogen or C1-C4 alkyl, and R1 and R2 are respectively and independently methyl or ethyl. According to the present invention, with the preparation method, the selectivity of the diphenyl carbonate compounds can be improved; and the used catalyst has characteristics of stable chemical property, safety, low prices and no corrosion to equipment, and is easily separated and recovered from the reaction solution. The formulas I, II and III are defined in the specification.
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Paragraph 0073; 0074
(2019/02/10)
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- Diphenyl carbonate compound preparation method
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The present invention relates to the field of diphenyl carbonate compounds, and discloses a diphenyl carbonate compound preparation method, which comprises: carrying out a transesterification reactionon a phenol compound represented by a formula (II) and a carbonic acid diester compound represented by a formula (III) in the presence of a catalyst, wherein R is hydrogen or C1-C4 alkyl, R1 and R2 are respectively and independently methyl or ethyl, and the catalyst contains a n-butyl imidazole quaternary ammonium salt. According to the present invention, with the preparation method, the selectivity of the diphenyl carbonate compounds can be improved; the used catalyst has characteristics of stable chemical property, safety, low prices and no corrosion to equipment, is easily separated and recovered from the reaction solution, and cannot cause negative impact on the environment; and the method is suitable for large-scale industrial production. The formulas I, II and III are defined in thespecification.
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Paragraph 0068-0069; 0070-0071; 0072-0073
(2019/02/10)
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- Production of diaryl carbonate
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The present invention provides a method for producing a diaryl carbonate and a method for producing an aromatic polycarbonate, and the method for producing the diaryl carbonate can remove the water, causing the degradation of a catalyst, in a manufacturing process of the diaryl carbonate without using a special device. The method for producing the diaryl carbonate of the present invention is a method for producing the diaryl carbonate from an aromatic monohydroxy compound and a dialkyl carbonate containing a compound represented by the following formula (1) in the presence of the catalyst, wherein The dialkyl carbonate contains 0.01 to 1000 mass ppm of the compound represented by the formula (1) in the dialkyl carbonate as a raw material (in the formula (1), R1, R2 R4 each independently represents an aliphatic group having 1 to 20 carbon atoms, and R3 represents a hydrogen atom or an aliphatic group having 1 to 20 carbon atoms.
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Paragraph 0110; 0114; 0115; 0116
(2018/09/02)
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- Direct C-C Bond Formation from Alkanes Using Ni-Photoredox Catalysis
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A method for direct cross coupling between unactivated C(sp3)-H bonds and chloroformates has been accomplished via nickel and photoredox catalysis. A diverse range of feedstock chemicals, such as (a)cyclic alkanes and toluenes, along with late-stage intermediates, undergo intermolecular C-C bond formation to afford esters under mild conditions using only 3 equiv of the C-H partner. Site selectivity is predictable according to bond strength and polarity trends that are consistent with the intermediacy of a chlorine radical as the hydrogen atom-abstracting species.
- Ackerman, Laura K. G.,Martinez Alvarado, Jesus I.,Doyle, Abigail G.
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supporting information
p. 14059 - 14063
(2018/10/24)
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- Preparation method of diphenyl carbonate compound
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The invention relates to the field of diphenyl carbonate compounds, and discloses a preparation method of a diphenyl carbonate compound. The preparation method comprises the following steps: carryingout transesterification reaction on a phenol compound shown in the formula (II) and the diphenyl carbonate compound shown in a structural formula (III) in the presence of a catalyst, wherein the catalyst is prepared from imidazole and potassium carbonate, wherein R is hydrogen or alkyl of C1 to C4, and R1 and R2 are separately and independently methyl or ethyl. According to the method, the selectivity of the diphenyl carbonate compound can be improved; the adopted catalyst has the advantages of a stable chemical property, security, low cost and no corrosion of equipment; meanwhile, the catalyst is easily separated and recycled from reaction liquid and is recycled. The formulae (I), (II) and (III) are shown in the description.
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Paragraph 0054-0067
(2018/11/22)
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- Preparation method of diphenyl carbonate compound
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The invention relates to the field of diphenyl carbonate compounds, and discloses a preparation method of a diphenyl carbonate compound. The preparation method comprises the following steps: carryingout transesterification reaction on a phenol compound shown in the formula (II) and the dialkyl carbonate compound shown in a formula (III) in the presence of a catalyst, wherein the catalyst is 1,4-diazabicyclo[2.2.2] octane, R is alkyl of C1 to C4, and R1 and R2 are separately and independently methyl or ethyl. According to the method, the selectivity of the diphenyl carbonate compound can be improved; the adopted catalyst has the advantages of a stable chemical property, security, low cost and no corrosion of equipment; meanwhile, the catalyst is easily separated and recycled from reactionliquid and is recycled. The formulae (I), (II) and (III) are shown in the description.
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Paragraph 0055; 0056; 0058; 0060; 0062; 0064; 0066; 0068
(2018/11/22)
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- Method of converting amide and urea into ester
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The invention provides a method of converting amide and urea into ester. In the method, different types of amide and urea are used as substrate, alcohol or phenol is used as nucleophile, iron salt is used as catalyst, and acid is used as additive, the conversion of amide and urea into ester is achieved under a mild condition. The method is characterized in that cheap iron salt is used as the catalyst, the commercialized amide, urea, and alcohol are used as the substrate, and the conversion of amide to ester is achieved in one step. The method has the advantages that the reaction condition is mild, the raw materials are cheap and easy to obtain, the reaction substrate is wide in adaptability, the selectivity and yield of the product are very high, the product is green and environmentally friendly and the like, and the method has good prospects for industrial applications.
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Paragraph 0069-0071
(2017/08/30)
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- A ionic liquid catalyzed transesterification preparation of diphenyl carbonate method and device (by machine translation)
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The invention discloses a ionic liquid catalyzed transesterification preparation of diphenyl carbonate method and device, comprising the following steps: (1) phenol with dimethyl carbonate in the ionic liquid catalyst under the conditions of benzene methyl ester carbonate ester exchange reaction; (2) in the ionic liquid catalyst under catalytic conditions in the disproportionation reaction to obtain the product of the diphenyl carbonate; (3) at the vacuum degree of 5 - 7 mmHg under the condition of reduced pressure distillation, in purity 99.6% more than the product of the diphenyl carbonate. This invention adopts the liquid ion catalyst, by transesterification reaction, disproportionation rectification to realize the two-step process, avoiding the use of highly toxic phosgene, the corrosion of the apparatus small; without the use of noble metal as the catalyst, mild reaction conditions, the requirements for apparatus is relatively low, the cost is low; this method can make the product yield of the diphenyl carbonate ≥ 80%, purity ≥ 99.6%; the device of the invention is simple in structure, easy to operate, can be continuously produced, improve the productivity. (by machine translation)
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Paragraph 0032-0034; 0041; 0044-0047; 0051-0054; 0055-0059
(2017/08/31)
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- Zn-promoted synthesis of diphenyl carbonate via transesterification over Ti–Zn double oxide catalyst
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An environmentally friendly heterogeneous catalyst, Ti–Zn double oxide, was prepared using a sol–gel method and firstly used for the synthesis of diphenyl carbonate (DPC) via the transesterification of phenol and dimethyl carbonate. The catalyst exhibited excellent catalytic activity. Moreover, the effects of Ti to Zn molar ratio, calcination temperature and catalyst amount on the catalytic performances of Ti–Zn double oxide have been investigated. The characterization results of XRD, TGA–DSC, ICP-AES and NH3-TPD showed that amorphous TiO2 was the active sites, and amorphous ZnO was the promoter. Also the amount of Zn remarkably affected the acid amounts of the catalysts, and the calcination temperature not only influenced the acid amount, but also affected the acid strength. Besides, the weak surface acid sites were responsible for the synthesis of MPC and DPC, whereas the strong acid sites favored the formation of a by-product, anisole. The phenol conversion and the transesterification selectivity reached 41.2 and 98.2% over 0.3?g 5TiZn-250 for 8?h, respectively. Furthermore, the prepared catalyst could be reused for three runs without drastic decrease in activity. The slight decreased activity was attributed to the phase change of Ti–Zn double oxide and the leaching of Ti.
- Qu, Yingmin,Wang, Songlin,Chen, Tong,Wang, Gongying
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p. 2725 - 2735
(2017/04/18)
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- Preparation method of diphenyl carbonate
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The invention relates to a preparation method of diphenyl carbonate, and mainly solves the problems of low activity and selectivity of heterogeneous catalysts in the prior art. The method includes: a) contacting dimethyl carbonate and phenol with a catalyst to carry out ester exchange reaction, wherein dimethyl carbonate gradually enters the reaction system in the reaction process, at the same time a mixture of dimethyl carbonate and methanol are distilled off through a rectification column, thus obtaining a mixture containing methyl phenyl carbonate and the catalyst at the column bottom; b) further subjecting the mixture containing methyl phenyl carbonate and the catalyst to reaction, at the same time distilling off a disproportionated product dimethyl carbonate by the rectification column, thus obtaining the product diphenyl carbonate at the column bottom. Specifically, the catalyst is titanium dioxide microsphere@all-silicon Silica-1 molecular sieve core-shell catalyst, the core phase is TiO2 microspheres, and the shell layer is all-silicon Silica-1 molecular sieve. The technical scheme well solves the problems, and can be used for the industrial production of diphenyl carbonate from dimethyl carbonate and phenol.
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Paragraph 0047; 0048; 0065; 0066; 0069; 0070
(2017/05/16)
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- The method of transesterification process for production of diphenyl carbonate
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The invention relates to a method for preparation of diphenyl carbonate by ester interchange, and mainly solves the problems that a heterogeneous phase catalyst has low activity and selectivity, and proneness to inactivation. In the invention, dimethyl carbonate and phenyl acetate, whose mol ratio ranges from 0.1 to 5, serve as materials, react in the presence of a catalyst for 1-20 hours at a temperature of 120-190 DEG C to prepare diphenyl carbonate, wherein the weight ratio of the catalyst to the phenyl acetate ranges from 0.01 to 0.5, the catalyst is a mixture of two metal oxides AaOb/ BcOd; A is selected from Sn, Mn or Bi, and B is selected from Al, Ga, Fe, In, Zr or Cr. The method for preparation of diphenyl carbonate by ester interchange solves problems well and can be used in ester interchange of dimethyl carbonate and phenyl acetate for preparing diphenyl carbonate.
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Paragraph 0025; 0026; 0027-0040
(2018/04/01)
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- Ionic liquids/ZnO nanoparticles as recyclable catalyst for polycarbonate depolymerization
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A useful protocol for waste bis-phenol A-polycarbonates (BPA-PC) chemical recycling is proposed based on a bifunctional acid/basic catalyst composed by nanostructured zinc oxide and tetrabutylammonium chloride (ZnO-NPs/NBu4Cl) in quality of Lewis acid and base, respectively. Retro-polymerization reaction proved to be of general application for several nucleophiles, including water, alcohols, amines, polyols, aminols and polyamines, leading to the complete recovery of BPA monomer and enabling the PC polymer to function as a green carbonylating agent (green phosgene alternative) for preparing carbonates, urethanes and ureas. A complete depolymerization can be obtained in seven hours at 100 °C and ZnO nanocatalyst can be recycled several times without sensible loss of activity. Remarkably, when polycarbonate is reacted with glycerol, it is possible to realize in a single process the conversion of two industrial wastes (BPA-PC and glycerol) into two valuable chemicals like BPA monomer and glycerol carbonate (the latter being a useful industrial solvent and fuel additive).
- Iannone, Francesco,Casiello, Michele,Monopoli, Antonio,Cotugno, Pietro,Sportelli, Maria Chiara,Picca, Rosaria Anna,Cioffi, Nicola,Dell'Anna, Maria M.,Nacci, Angelo
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p. 107 - 116
(2016/12/09)
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- Method for one-step catalytic synthesis of diphenyl carbonate from carbon dioxide and phenol
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The invention belongs to the technical field of chemical synthesis, and concretely relates to a method for one-step catalytic synthesis of diphenyl carbonate from carbon dioxide and phenol. Diphenyl carbonate is synthesized through a reaction of carbon dioxide and phenol in CCl4 in a high pressure reaction kettle under the catalysis of spinel-type nanometer ferrite with a nitrogen-containing compound as an assistant. The catalyst has nanometer particle dimension and high specific surface area, has high activity in catalytic reactions, and allows the yield of diphenyl carbonate to be higher than the yield of diphenyl carbonate synthesized in the prior art. The catalyst is magnetic, can realize enrichment recovery of the catalyst and high dispersion of the catalyst in a reaction system and overcome the defect of difficulty in separation of the catalyst from the reaction system through applied magnetic field, and is of great significance in economy and society.
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Paragraph 0023-0041
(2017/08/27)
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- Method for synthesizing carbonic ester by using carbon dioxide at ordinary pressure
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The invention discloses a method for synthesizing carbonic ester by using carbon dioxide at ordinary pressure. According to the method, the carbon dioxide is continuously introduced in a reaction system in the reaction process, constant ordinary pressure is maintained by the system, and reaction is conducted in a non-pressure resistance reactor. Lewis acid and quaternary ammonium salt are adopted by the method to form a co-catalysis system, a catalyst is cheap and easy to obtain, the operation is simple, the reaction condition is mild, and the catalytic activity is high. In an optimized reaction condition, i.e., in the ordinary pressure, reaction is conducted for 3h at 100 DEG C, the yield of cyclic carbonate is 69.5-90.2%, and the yield of diphenyl carbonate is 8.6%. The method has the advantages that the reaction can be efficiently conducted in a common non-pressure resistance reactor, the operation is safe, and the large-scale industrial production is favorably realized.
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Paragraph 0027; 0028
(2018/04/01)
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- Method for synthesizing diphenyl carbonate by employing ionic liquid as accelerant
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The invention relates to a method for synthesizing diphenyl carbonate by employing an ionic liquid as an accelerant. According to the method, the ionic liquid is adopted as a catalytic phenol and is exchanged with dimethyl carbonate to synthesize an accelerant of a diphenyl carbonate metal organic matter catalyst. Through the synergistic effect of the ionic liquid and a metal organic matter, separation of dimethyl carbonate and methyl alcohol is significantly improved, the catalytic activity of the metal organic matter is improved and the yield of diphenyl carbonate DPC and methyl phenyl carbonate MPC is improved, wherein the conversion rate of DMC is greater than 50% and the yield of DPC is greater than 80%; and the energy consumption of the method is lower. According to the method, generation of a by-product anisole in transesterification of DMC and phenol is inhibited to a great extent; and an azeotropic composition of DMC and methyl alcohol is changed and methyl alcohol is more easily separated from a reaction system, so that the yield of DPC and MPC is significantly improved.
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Paragraph 0035-0089
(2017/08/29)
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- Ionic liquid catalysis transesterification preparation diphenyl carbonate's device
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This device discloses an ionic liquid catalysis transesterification preparation diphenyl carbonate's device, including reaction - rectifying column, first reboiler, first condenser, disproportionation ware, second condensing tower, distillation column, light component tower and product tower, export of reaction - rectifying column top of the tower and first condenser entry linkage, the export of first condenser divide into two branch roads, respectively with waste liquor recovery jar and reaction - rectifying column, export of reaction - rectification tata cauldron and disproportionation ware entry linkage, export of disproportionation ware top and second condenser entry linkage, the export of second condenser divide into two branch roads, be connected with waste liquor recovery jar and disproportionation ware respectively, export of disproportionation ware bottom and distillation column entry linkage, export of distillation column top and light component tower entry linkage, export and product tower entry linkage at the bottom of the light component tata. This device simple structure, easy operation, but serialization production can make result diphenyl carbonate's productivity >= 80%, purity >= 99.6%.
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Paragraph 0029; 0032; 0033; 0034; 0035
(2016/10/07)
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- Method for preparing diphenyl carbonate
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The invention relates to a method for preparing diphenyl carbonate to mainly solve the problems of low heterogeneous phase catalyst activity and low selectivity existing in the prior art. The method comprises the following steps: 1, allowing dimethyl carbonate and phenol to be in contact with a catalyst and to undergo an ester interchange reaction, wherein dimethyl carbonate gradually enters a reaction system in the reaction process, a dimethyl carbonate and methanol mixture is distilled off through a rectifying column, and a mixture containing methyl phenyl carbonate and the catalyst is obtained at column bottom; and 2, continuously reacting the mixture containing methyl phenyl carbonate and the catalyst, and distilling off a disproportionation product dimethyl carbonate through the rectifying column to obtain the product diphenyl carbonate at the column bottom, wherein he catalyst is a binary mixed metal oxide AaOb/BcOd, A is Sn, Mn or Bi, and B is Al, Ga, Fe, In, Zr or Cr. The method adopting the above technical scheme well solves the problems, and can be used in industrial production for preparing diphenyl carbonate from dimethyl carbonate and phenol.
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Paragraph 0030; 0031
(2017/01/02)
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- Simple and efficient production method for phenyl chloroformate
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The invention provides a simple and efficient production method for phenyl chloroformate. The production method comprises the following steps that firstly, phenol is treated into a molten state for use; secondly, phenol is transferred into a phenol spray tank, and a catalyst is transferred into a catalyst spray tank; thirdly, a circulating refrigerating machine is started, then a temperature control pipeline is controlled, a reaction tank is heated, phosgene is introduced into the reaction tank continuously, then the phenol spray tank is started, stirring is started, the catalyst spray tank is started, and central control samples are taken; finally, gas dispelling is carried out on the reaction tank with nitrogen, and phenyl chloroformate is obtained through reduced pressure distillation. Compared with an existing production technology, by means of the simple and efficient production method for phenyl chloroformate, the reaction time is shortened, and the purity and the reaction efficiency are improved.
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Paragraph 0021-0031; 0035; 0046; 0057; 0065
(2018/02/03)
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- Method of manufacturing [...]
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The present application relates to a method for the continuous production of diaryl carbonate from phosgene and of at least one monohydroxy compound (monophenol) in the presence of catalysts, and to the use thereof for the production of polycarbonates.
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Paragraph 0064-0065
(2016/10/08)
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- Method for preparing diphenyl carbonate through transesterification
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The invention relates to a method for preparing diphenyl carbonate through transesterification. With prior arts, heterogeneous catalyst activity and selectivity are low, and the catalyst is prone to inactivation. The invention mainly aims at solving the above problems. According to the invention, dimethyl carbonate and phenyl acetate are adopted as raw material, and contact a catalyst for 1-20h under a reaction temperature of 120-190 DEG C, wherein a molar ratio of dimethyl carbonate to phenyl acetate is 0.1-5, and a weight ratio of the catalyst to phenyl acetate is 0.01-0.5. With the above reaction, diphenyl carbonate is produced. The catalyst is a binary mixed metal oxide AaOb/BcOd, wherein A is Sn, Mn or Bi; and B is Al, Ga, Fe, In, Zr or Cr. With the technical scheme, the problems are well solved. The method can be used in industrial productions for preparing diphenyl carbonate through the transesterification reaction of dimethyl carbonate and phenyl acetate.
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Paragraph 0025; 0026
(2017/03/14)
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- INTEGRATED METHOD AND APPARATUS FOR THE PRODUCTION OF ARYL CARBONATES
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In an embodiment, a method for producing an alkyl aryl carbonate, comprises producing a dialkyl carbonate azeotrope stream comprising a dialkyl carbonate and an unreacted alkanol; purifying the dialkyl carbonate azeotrope stream in a dialkyl carbonate purification section comprising a distillation column and a pervaporation unit to provide a first purified dialkyl carbonate stream and a first purified alkanol stream; reacting the first purified dialkyl carbonate stream and an aromatic alcohol in the presence of a second transesterification catalyst in an alkyl aryl carbonate reactor to produce an alkanol product stream comprising an alkanol product and an unreacted dialkyl carbonate, and an alkyl aryl carbonate product stream comprising the alkyl aryl carbonate and an unreacted aromatic alcohol; and purifying the alkanol product stream in the dialkyl carbonate purification section.
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Paragraph 0072
(2016/10/11)
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- MANUFACTURING METHOD OF DIPHENYL CARBONATE AND MANUFACTURING METHOD OF POLYCARBONATE
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PROBLEM TO BE SOLVED: To manufacture high purity diphenyl oxalate efficiently, stably and continuously with a simple method. SOLUTION: There is provided a manufacturing method of diphenyl carbonate by a decarbonylation reaction of diphenyl oxalate in the presence of a catalyst, where the diphenyl oxalate contains 0.076 wt.% or more and 10 wt.% or less of phenyl carbonate ester represented the following general formula (1), where n is 1 or 2. It preferably has a first step for manufacturing diphenyl carbonate by a decarbonylation reaction, a second step for separating the diphenyl carbonate manufactured in the first step and a catalyst liquid and a third step for recycling at least a part of the catalyst liquid separated in the second step to the first step in this order. There is provided a manufacturing method of polycarbonate including a condensation polymerization with a dihydroxy compound after manufacturing the diphenyl carbonate by the method. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0063
(2017/03/08)
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- PRODUCTION METHOD OF DIPHENYL CARBONATE, AND PRODUCTION METHOD OF POLYCARBONATE
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PROBLEM TO BE SOLVED: To provide a method for efficiently, stably, and via a simple procedure producing diphenyl carbonate with high purity. SOLUTION: In a production method of diphenyl carbonate, diphenyl oxalate is subjected to a decarbonylation reaction in the presence of a catalyst, in which absolute pressure at the time of the decarbonylation reaction is 0.105 to 10 MPa, and in which the catalyst is preferably tetraarylphosphonium halide. The absolute pressure at the time of the decarbonylation reaction is preferably controlled by adjustment in accordance with the discharge amount of carbon monoxide by-produced in the decarbonylation reaction. Besides the by-produced carbon monoxide is preferably used as a production raw material of diphenyl oxalate, and it is especially preferable to produce diphenyl carbonate by using the diphenyl oxalate produced from the by-produced carbon monoxide as a production raw material. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0062; 0063
(2017/06/02)
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- A method of manufacturing a carbonate diester tetraarylphosphonium asymmetrical and method of manufacturing
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PROBLEM TO BE SOLVED: To produce an unsymmetrical tetraarylphosphonium halide in good yield and at a high selectivity rate while suppressing generation of byproducts, when producing the unsymmetrical tetraarylphosphonium halide by reacting triarylphosphine and haloginated aryl in the presence of a metal halide compound as a catalyst, and an aqueous solvent having a high boiling point.SOLUTION: Triarylphosphine is added fractionally or continuously to a reaction solution containing aryl halide, a metal halide compound as a catalyst and an aqueous solvent having a high boiling point.
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Paragraph 0088
(2017/03/28)
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- METHOD AND APPARATUS FOR THE PRODUCTION OF DIARYL CARBONATE
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The present application describes a method for producing diaryl carbonate. The method includes a step of reacting dialkyl carbonate, aromatic alcohol and a catalyst precursor in a first distillation column to give rise to diaryl carbonate. The method includes a step for reacting, in the first distillation column, the aromatic alcohol with the catalyst precursor to produce a catalyst. The method also includes a step of recovering from the first distillation column a first top stream that comprises an alkyl alcohol evolved in the first distillation column. The present application also describes a system for the production of diaryl carbonate. The system includes a first distillation column including one or more inlets.
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Paragraph 0062
(2016/10/11)
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- Coupling of a kind of fixed bed preparation of diphenyl carbonate rectifying method and device for
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The invention discloses a method and device for preparing diphenyl carbonate by virtue of a fixed bed coupled with a distillation tower. Particularly, the method for producing diphenyl carbonate comprises the following steps of carrying out reaction on dimethyl carbonate and phenol serving as raw materials in the presence of a catalyst in a fixed bed to produce methyl phenyl carbonate and diphenyl carbonate, feeding into a distillation tower for separating to obtain diphenyl carbonate, wherein the fixed bed is coupled with the distillation tower. The preparation device comprises a fixed bed reaction unit, a distillation unit, a purification unit and a vacuum system. By virtue of the method and device disclosed by the invention, the problem of difficulty in post-treatment of a homogeneous catalyst is overcome, the conversion rate can be effectively improved, the yield is increased, and compared with the conventional reactive distillation process, the preparation method has the advantages that the energy consumption is lower, the efficiency is higher, equipment investment can be effectively saved and the production cost is reduced; the method disclosed by the invention belongs to a process method of continuous production and is conducive to improvement of the yield per unit of the device and the output of the industrial production and thus the method has relatively good industrial applicability.
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Paragraph 0042-0045
(2017/06/24)
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