Palladium-lead catalyzed oxidative carbonylation of phenol1Part of this work has appeared in a patent literature. M. Takagi, H. Miyagi, Y. Ohgomori, H. Iwane, US Patent 5498789.1

Takagi, Motoki; Miyagi, Hidekazu; Yoneyama, Takahiro; Ohgomori, Yuji

doi:10.1016/s1381-1169(97)00188-x

Cited by 67 publications

(34 citation statements)

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“…1,2 So far, various approaches for DPC synthesis have been reported, including phosgene route, oxidative carbonylation of phenol and transesterification reaction. 1,[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Among them, transesterification of dimethyl oxalate (DMO) with phenol to diphenyl oxalate (DPO), following a decarbonylation reaction, is an attractive and environmentally friendly route for the synthesis of DPC. [13][14][15][16][17][18][19] Liu et al 2255 Vol.…”

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confidence: 99%

Comparative study on the catalytic properties of amino-functionalized silica materials for the transesterification of dimethyl oxalate with phenol

Liu¹,

Zhao²,

Zhu³

et al. 2010

J. Braz. Chem. Soc.

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Uma série de materiais híbridos mesoporos MCM-41, contendo diferentes grupos amino (como 3-aminopropila (AP-), (2-aminoetilamino)propila (AAP-), ou [2-(2-aminoetilamino) etilamino]propila (AEP-)) foi preparada pelo método de pós-enxertia e caracterizada por difração de raio X de pó (XRD), adsorção de N 2 , espectroscopia de infravermelho com transformada de Fourier (FT-IR) e dessorção de CO 2 com temperatura controlada (CO 2 -TPD). As propriedades catalíticas destes materiais híbridos para a reação de transesterificação de dimetil oxalato com fenol foram investigadas. Verificou-se que todos são ativos, particularmente o AEP-MCM-41, que apresentou a maior atividade dentre eles. Apenas um pequeno decréscimo na atividade foi observado após vários ensaios catalíticos sucessivos utilizando o mesmo catalisador, indicando uma boa reciclabilidade do mesmo. Notavelmente, a atividade do catalisador pode ser regenerado por simples tratamento com base, sob condições brandas. Além disso, os efeitos da densidade e da força básica dos grupos amino sobre as propriedades catalíticas foram exploradas na proposição do mecanismo de reação, incluindo a provável rota que leva à formação do subproduto anisol.A series of hybrid mesoporous MCM-41 materials containing different amino groups (such as 3-aminopropyl (AP-), (2-aminoethylamino)propyl (AAP-), or [2-(2-aminoethylamino)ethylamino] propyl (AEP-) group) were prepared by a post-grafting method, and characterized by means of X-ray powder diffraction (XRD), N 2 adsorption, Fourier transform-infrared spectroscopy (FT-IR) and temperature-programmed desorption of CO 2 (CO 2 -TPD). The catalytic properties of these hybrid materials were investigated for the transesterification of dimethyl oxalate with phenol. All the samples were active for the transesterification. Among them, the sample AEP-MCM-41 exhibited the highest activity under test conditions. And only a slight decrease in activity could be observed after few runs, indicating the good recyclability of this catalyst. Notably, the activity of the used catalyst could be regenerated by simple treatment with diluted basic agents under mild conditions. Moreover, effects of the density and the basic strength of the amino groups on the catalytic properties were taken into consideration for understanding the reaction mechanism and the possible formation route of the by-product anisole.Keywords: amino-functionalized, MCM-41, dimethyl oxalate, transesterification, recyclability IntroductionDiphenyl carbonate (DPC) is an industrially important intermediate for the production of several organic chemicals, especially as the precursor for the synthesis of polycarbonates (PCs), which have been used in many fields due to excellent mechanical, optical, electrical and heatresistance properties. 1,2 So far, various approaches for DPC synthesis have been reported, including phosgene route, oxidative carbonylation of phenol and transesterification reaction. 1,[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Among them, transesterification...

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Comparative study on the catalytic properties of amino-functionalized silica materials for the transesterification of dimethyl oxalate with phenol

Liu¹,

Zhao²,

Zhu³

et al. 2010

J. Braz. Chem. Soc.

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“…The Wowtab product dissolves quickly in 15 s or less. Wowtab product can be packed in both into conventional bottle and blister packs [39]. Flashtab technology-The Flashtab technology is yet another fast dissolving/disintegrating tablet formulation.…”

Section: Quick-dismentioning

confidence: 99%

Development of Fast Disintegration Tablets As Oral Drug Delivery System-A Review

Beri¹,

Sacher²

2013

IJPBR

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Fast disintegrating tablets (FDTs) have received increasing demand from the last few years and the field has become a rapidly growing field in the pharmaceutical industry. Fast disintegrating tablets (FDTs) are those solid doses form which when put on the tongue gets rapidly dissolved, releasing the drug within a few second without need of water. The development of FDTs have been formulated for paediatric, geriatric and bedridden patients and for active patients who are busy and travelling and may not have access to water. Such formulation provide an opportunity for product line extension in the many elderly persons will have difficulties in taking conventional oral doses forms (viz, solution suspensions tablet and capsules) because of hand tremors and dysphagia. This article focused on ideal requirements, need for development of FDTs, challenges in formulations, suitability of drug candidates superdisintegrants employed, various technologies developed for FDTs. Evaluation methods, and various marketed products.

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“…6 However, direct oxidative carbonylation of phenol to DPC has usually been catalyzed by Pd complexes and inorganic/organic cocatalysts following the well-known 'redox' or 'multi-step electron transfer mechanism', 7 -12 and 3Å molecular sieves (MS) are employed as a dehydrating agent to remove water produced during the reaction. 13 -15 To facilitate recovery of the noble palladium catalyst in homogeneous reactions, heterogenized Pd complexes 19 and supported metallic palladium on activated carbon 4,20,21 have been developed. However, the catalysts prepared by polymer graft techniques cannot bear high temperatures.…”

Section: Introductionmentioning

confidence: 99%

Oxidative carbonylation of phenol to diphenyl carbonate catalyzed by palladium complexes bridged with N,N‐ligands over functionalized silica

Fan

2006

Applied Organom Chemis

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Heterogeneous palladium catalysts anchored on functionalized silica were prepared by sol-gel methods and their catalytic properties for the oxidative carbonylation of phenol to diphenyl carbonate (DPC) were investigated. The catalysts were characterized by means of IR, XPS, EA and BET. The Pd loading in the heterogeneous catalysts and leaching in solution were detected by atomic absorption. The effects of different reaction parameters such as temperature, solvent and inorganic cocatalyst on the yield of DPC and Pd leaching were also studied. It was found that Cu 2 O and tetrahydrofuran (THF) were the best partners with these heterogeneous catalysts. In the presence of 3Å molecular sieves as dehydrating agent, the heterogeneous palladium catalyst prepared from 2-acylpyridine revealed excellent catalytic performance and stability at 110 • C for 5 h, giving 13.7% yield of DPC based on phenol and 4.0% Pd loss in solution. The heterogeneous catalyst was more active and stable compared with traditional supported Pd-C catalyst under the same reaction conditions.

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Palladium-lead catalyzed oxidative carbonylation of phenol1Part of this work has appeared in a patent literature. M. Takagi, H. Miyagi, Y. Ohgomori, H. Iwane, US Patent 5498789.1

Cited by 67 publications

References 4 publications

Comparative study on the catalytic properties of amino-functionalized silica materials for the transesterification of dimethyl oxalate with phenol

Comparative study on the catalytic properties of amino-functionalized silica materials for the transesterification of dimethyl oxalate with phenol

Development of Fast Disintegration Tablets As Oral Drug Delivery System-A Review

Oxidative carbonylation of phenol to diphenyl carbonate catalyzed by palladium complexes bridged with N,N‐ligands over functionalized silica

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