- Novel synthetic method of camphorquinone
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The invention relates to a novel synthetic method of camphorquinone, which is a method for preparing camphorquinone from camphor in the presence of a catalyst. The invention further provides a methodfor preparing camphorquinone, which can effectively reduce the toxicity of the used catalyst and reflect the harm to the environment, and ensures a high yield of the reaction while simplifying the process flow. According to the method, clean energy microwave irradiation instead of conventional energy is utilized, so that the pollution of the reaction to the environment is greatly reduced while thereaction yield is ensured, and the purpose of green chemistry is met.
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Paragraph 0018-0019
(2020/05/30)
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- Selectively polymerizable compositions and methods of use in vivo
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Otologic materials and methods are provided. For example, a cell-adhesive, biodegradable hydrogel scaffold loaded with time-released drugs for repairing chronic tympanic membrane perforations is disclosed, methods of making same and administering same are provided. This hydrogel may promote vascular in-growth and epithelial cell growth of the tympanic membrane with the purpose of closing the perforation and providing a barrier between the external and middle ear. The hydrogel is initially a liquid polymer that only gels upon exposure to specific conditions, such as exposure to light. This scaffold may simultaneously induce repair of the tympanic membrane while preventing or alleviating middle ear infection, thus filling a void in current tympanic membrane perforation therapies.
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- Method for producing camphorquinone by taking byproduct generated in camphor synthesis process as raw material
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The invention provides a method for producing camphorquinone by taking a byproduct generated in the camphor synthesis process as a raw material, belonging to the technical field of organic synthesis.The byproduct 3-camphene ester generated in the synthesis process of camphor is used as a starting material to prepare high-purity camphorquinone through refining, saponification, dehydrogenation, condensation, hydrolysis and recrystallization steps. The method has the beneficial effects that the value of the byproduct generated in the camphor synthesis process is used, industrial wastes are reduced, wastes are changed into valuables, environmental pressure is reduced, a brand-new path for the synthesis of the camphorquinone is provided, no heavy metals are used in all process steps, truly nontoxic chemical synthesis of the camphorquinone is realized, and the method is an economic and environment-friendly production process.
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Paragraph 0050; 0051
(2019/09/14)
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- Selectivity of the complexation reactions of four regioisomeric methylcamphorquinoxaline ligands with gold(III): X-ray, NMR and DFT investigations
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Reported are the synthesis, spectral and structural characteristics of new quinoxaline-related regioisomeric ligands L1-L4 (1,x,11,11-tetramethyl-1,2,3,4-tetrahydro-1,4-methanophenazine, x = 7, 8, 9 and 6, respectively) and their mononuclear Au(III) complexes (1-4). Fusion of the camphor moiety to the quinoxaline core made two N-atoms of quinoxaline nonequivalent while the introduction of a methyl-substituent at positions 6-9 enabled a tuning of coordination properties of L1-L4. Gold(III) complexes 1-4 and ligands L1-L4 have been studied in detailed by 1D and 2D NMR and the structures of 1-4 have been determined by X-ray crystallography. The results of these analyses revealed a regiospecific coordination of Au(III) to the sterically less hindered N-5 atom (spatially close to the non-substituted bridgehead carbon) of L1-L3, and to N-10 (spatially close to the methyl-substituted bridgehead carbon) of L4. The results of DFT calculations shed light on disparate coordination modes of L1-L4 toward the AuCl3 fragment and explain formation of single coordination products in high yield.
- Gli?i?, Biljana D.,Hoffmann, Marcin,Warzajtis, Beata,Gen?i?, Marija S.,Blagojevi?, Polina D.,Radulovi?, Niko S.,Rychlewska, Urszula,Djuran, Milo? I.
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p. 137 - 149
(2016/01/15)
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- A phenanthroline-derived ligand and its complexation with Pd(II): From ligand design, synthesis and Pd(II) complexes structures to its application
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A novel phenanthroline-derived bis-opened-triazine ligand for selective complexation with Pd(ii) over 19 typical metals from HNO3 media was designed based on cavity modulation strategy. Structures of the three species of the Pd(ii) complexes of with the ligand were elucidated by 1H NMR titration isothermal titration calorimetry (ITC) and density functional theory (DFT) studies. ITC test and binding energy calculations demonstrated that the asymmetrical 1:1 Pd(ii)-ligand complex with a monodentate nitrate anion was the most stable among these three species of the Pd(ii) complexes. The excellent kinetics of Pd(ii) extraction with the ligand is due to its optimal conformation completely ready for metal ligation. The enhanced special extraction selectivity and fast extraction rate towards Pd(ii) achieved by the phenanthroline-derived ligand demonstrated that the effective separation of some radionuclides with smaller radius in HLW through cavity modulation strategy is a feasible approach.
- Xu, Lei,Zhang, Anyun,Lu, Yanchao,Yang, Hua,Liu, Ziyang
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p. 99859 - 99866
(2016/11/09)
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- SELECTIVELY POLYMERIZABLE COMPOSITIONS AND METHODS OF USE IN VIVO
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Otologic materials and methods are provided. For example, a cell-adhesive, biodegradable hydrogel scaffold loaded with time-released drugs for repairing chronic tympanic membrane perforations is disclosed, methods of making same and administering same are provided. This hydrogel may promote vascular in-growth and epithelial cell growth of the tympanic membrane with the purpose of closing the perforation and providing a barrier between the external and middle ear. The hydrogel is initially a liquid polymer that only gels upon exposure to specific conditions, such as exposure to light. This scaffold may simultaneously induce repair of the tympanic membrane while preventing or alleviating middle ear infection, thus filling a void in current tympanic membrane perforation therapies.
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Page/Page column
(2015/04/28)
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- METHOD FOR MANUFACTURING ESTER
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The present invention relates to a method for manufacturing an ester from a ketone or an aldehyde, which is a reactive substrate, by a Baeyer-Villiger oxidation reaction using hydrogen peroxide, and in this method, as a catalyst, M(BAr4)n, which is a metal borate, is used (M represents an alkali metal or an alkaline earth metal; Ar represents an aryl; and n is the same number as the valence of M). For example, when cyclohexanone was used as the reactive substrate, and Sr[B(3,5-CF3C6H3)4]2 was used as the catalyst, ε-caprolactone was obtained at an isolated yield of 82%.
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Paragraph 0070; 0074; 0090
(2013/08/28)
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- Efficient synthesis of camphorquinone from camphor
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In this study, we discussed an efficient approach for the synthesis of camphorquinone from camphor by the continuous reaction of bromination and oxidation. The oxidation of 3-bromocamphor was catalyzed by Fe-porphyrins with air. The catalytic activity of iron-metallated functional porphyrins was investigated under optimization conditions. The results showed that this method was a milder alternative to the reported methods, with a simple, greener procedure in which the advantages were the utilization of air as the oxidant and the use of metalloporphyrins as catalysts. Copyright Taylor & Francis Group, LLC.
- Wang, Jian,Li, Peng,Ni, Chengliang,Yan, Hong,Zhong, Rugang
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p. 1543 - 1548
(2013/05/22)
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- An environment friendly preparation of 3-bromocamphor and camphorquinone
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The bromination of camphor has been carried out on a multi-gram scale by a mixture of KBr and KBrO3 in the presence of acid or with HBr/NaBr - H+ and H2O2/oxone as the oxidant. The 3-bromocamphor is then efficiently converted to camphorquinone by an improved oxidation protocol using DMSO and sodium carbonate of tetrabutyl ammonium iodide.
- Kannappan, Jayaraman,Bedekar, Ashutosh V.
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experimental part
p. 141 - 143
(2012/10/07)
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- Oxidative cleavage of vicinal diols: IBX can do what Dess-Martin periodinane (DMP) can
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A study was conducted to demonstrate the similarity of reactivity between o-iodoxybenzoic acid (IBX), an oxidative agent of vicinal diols and Des-Martin periodinane (DMP). The study examined IBX-mediated oxidative cleavage of tert,tert-1,2-diols and discovered pathways that favored fragmentation of sec,sec-1,2-diols, which produce non-cleavage products. It was observed that IBX can be employed to perform oxidative cleavage of 1,2-diols similar to DMP by simple variation of solvent and temperature. It was also observed that protonation of 10-1-4 species of diols may suppress the nucleophilic attack, leading to the production of ketol to achieve oxidative cleavage of sec,sec-1,2-diols that yield non-cleavage products with IBX in DMSO. TFA was used as a significant source of protons and a better solvent of IBX to conduct protonation of diols. A variety of sec,sec,tert,tert and sec,tert syn-1,2-diols underwent oxidative cleavage effectively, using TFA as a solvent.
- Moorthy, Jarugu Narasimha,Singhal, Nidhi,Senapati, Kalyan
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p. 767 - 771
(2008/03/27)
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- Microwave-assisted selenium dioxide oxidation of camphor derivatives to α-dicarbonyl compounds and oxoimines
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Camphor-derived α-dicarbonyl compounds and 3-oxo-camphorsulfonylimine have been synthesized from the corresponding ketones or sulfonylimine by microwave-assisted oxidation with selenium dioxide. Compared to the classical reaction conditions, good yields were obtained in much shorter reaction times. Additionally, the selenium precipitation is more quantitative, and its removal from the reaction mixture is easier. Copyright Taylor & Francis Group, LLC.
- Belsey, Sarah,Danks, Timothy N.,Wagner, Gabriele
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p. 1019 - 1024
(2007/10/03)
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- Efficient chemoselective mild deprotection of S,S-and S,O-acetals and ketals with electrophilic halogens
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A novel and simple method for the chemoselective deprotection of S,S- and S,O-acetals and ketals in the presence of their O,O-analogs with electrophilic halogens to their corresponding carbonyl compounds is described using N-bromosuccinimide, N-chlorosuccinimide, 2,4,4,6-tetrabromo-2,5-cyclohexen-1- one, trichlorocyanuric acid, or molecular bromine in aqueous acetonitrile. The use of these reagents in the presence of hydrated silica gel provide efficient, novel, and mild procedures for the deprotection of cyclic and acyclic O,O-, S,S-, and S,O-acetals and ketals in excellent yields in short reaction times. Copyright Taylor & Francis Group, LLC.
- Shaterian, Hamid Reza,Hadadzadeh, Hassan
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p. 1059 - 1071
(2007/10/03)
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- Catalytic and chemoselective deprotection of S,S- and S,O-acetals and ketals in the presence of their O,O-analogs with electrophilic halogens under neutral conditions
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A novel and catalytic method is described for the selective deprotection of S,S- and S,O-acetals and ketals in the presence of their O,O-analogs to their corresponding carbonyl compounds based on the use of N-bromosuccinimide (NBS), N-chlorosuccinimide (NCS), 2,4,4,6-tetrabromo-2,5-cyclohexadiene-1-one (TABCO), trichlorocyanuric acid (TCCA) or molecular bromine as sources of electrophilic halogens in the presence of DMSO as the source of oxygen in CHCl3.
- Iranpoor, Nasser,Firouzabadi, Habib,Shaterian, Hamid Reza
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p. 4769 - 4773
(2007/10/03)
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- Method for the synthesis of a taxane intermediate
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A process for the preparation of a compound having the formula: in which a compound having the formula: is treated with a base and a silylating agent.
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- An improved synthesis of camphorquinone-3-oxime
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Camphorquinone 3-oxime is prepared in 77% yield in one step from camphor. The synthesis avoids the use of toxic selenium reagents, and provides the syn compound as the major stereoisomer.
- Love, Brian E.,Jones, Edward G.
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p. 2831 - 2840
(2007/10/03)
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- NOVEL AND EFFICIENT ONE-POT SYNTHESIS OF PHOSPHORUS HETEROCYCLES CONTAINING THE BICYCLOHEPTENE MOIETY
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In a convenient one-pot sequence, treatment of camphorquinone with sodium in dry tetrahydrofuran followed by addition of phosphorodichloridate and phosphorothiodichloridate yields 2-oxo-1,3,2-dioxaphospholes and 2-thioxo-1,3,2-dioxaphospholes, respectively.Similar treatment of 3-phenyliminobornan-2-one with sodium in dry THF followed by addition of phosphorodichloridate and phsphorothiodichloridate yields 2-oxo-1,3,2-oxazaphospholes and 2-thioxo-1,3,2-oxazaphospholes.Key words: Camphorquinone, 3-phenyliminobornan-2-one, phosphorodichloridate, phosphorothiodichloridate, dioxaphospholes, oxazaphospholes.
- Singh, M. S.
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p. 187 - 192
(2007/10/03)
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- Structural Effects Affecting Hydration of 1,2-Diones Studied by Linear-Sweep Voltammetry
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Linear-sweep voltammetry was used for determination of values KdCO = and KdCO = +R'>+)R'> for some aliphatic and alicyclic 1,2-diketones.Values obtained were compared with data obtained from UV and NMR spectra.Dc polarographic data were used to choose the most reliable value.In all cases, the protonated form predominating in solutions of sulfuric acid is less strongly hydrated than the unprotonated form.The effect of ring size on the hydration in polycyclic species is discussed.Steric hindrance of the hydration due to the 7- and possibly the 1-methyl group in 2,3-camphorquinone has been confirmed.
- Segretario, James P.,Sleszynski, Neal,Partch, Richard E.,Zuman, Petr,Horak, Vaclav
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p. 5393 - 5396
(2007/10/02)
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- UNTERSUCHUNGEN AN DIAZOVERBINDUNGEN UND AZIDEN-LIII. ABFANGREAKTIONEN INSTABILER AZOMETHINIMIN-DIPOLE MIT ETHANOL
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The reaction of the diazo compounds 1a-o with 4-phenyl-1,2,4-triazolin-3,5-dione (2) in dichloromethane-ethanol leads to the urazoles 5a-o; they arise from the primarily formed unstable azomethinimine dipoles 4a-o by ethanol addition.Acidic hydrolysis of 5k and 5o yields the α-diketones 8 and 10 besides 4-phenyl urazole (9).Bistriazolindinones (13a,b) react analogously with diazo compounds (1l, m) in the presence of ethanol to give the bisurazoles 14a-c.
- Theis, W.,Bethaeuser, W.,Regitz, M.
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p. 1965 - 1972
(2007/10/02)
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- Kinetic Resolution of 1,2-Diols with D-Camphorquinone; Preparation of (R)-(Chloromethyl)oxirane
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Acid-catalysed reaction of D-camphorquinone with racemic 1,2-diols (e.g. 3-chloropropane-1,2-diol) under kinetically controlled conditions yields a predominant diastereoisomeric acetal, that can be easily converted into an optically pure epoxide.
- Ellis, Martin K.,Golding, Bernard T.,Watson, William P.
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p. 1600 - 1602
(2007/10/02)
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- Role of Metal Ions in Reactions of dl-Camphorquinone with Monoamines
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The condensation of monoamines with dl-camphorquinone in the presence of metal ions (Co2+, Ni2+, Cu2+) gave two classes of metal complexes.The reactions leading to Class 1 complexes gave monoimines with the imino group at C(2) and C(3) positions.The reactions leading to Class II complexes gave monoimines with the imino group at C(3) position only, similar to that obtained by the direct condensation reaction in the absence of a metal ion.A diimine is also obtained in a reaction involving copper(II) complexes of Class I.
- Mukhedkar, V. A.,Rajgolkar, R. L.,Mukhedkar, A. J.
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p. 295 - 299
(2007/10/02)
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- PHOTOSENSITIZED OXYGENATION OF 3-DIAZOCAMPHOR
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Photosensitized oxygenation of 3-diazocamphor gave camphorquinone and camphoric anhydride in benzene.The yield of camphoric anhydride did not depend on the concentration of added camphorquinone or of diazocamphor.When the reaction was carried out in acetonitrile or benzonitrile, amide 7 or 8 was produced.The formation of amide strongly supports the intermediacy of carbonyl oxide.
- Okada, Keiji,Mukai, Toshio
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p. 359 - 360
(2007/10/02)
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- Conversion of Thiocarbonyl Compounds into their Corresponding Oxo-derivatives using Benzeneseleninic Anhydride
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A series of thiocarbonyl compounds including xanthates, thioesters, thioureas, thiocarbonates, and thiones have been converted into their oxo-analogues by treatment with benzeneseleninic anhydride in tetrahydrofuran at room temperature.Except for readily enolised thiones where further oxidation can take place, the method works well and compares favourably with other literature procedures.One example of a selenocarbonyl ester was likewise converted efficiently into the corresponding ester.
- Cussans, Nigel J.,Ley, Steven V.,Barton, Derek H. R.
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p. 1650 - 1653
(2007/10/02)
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- Reactions of Pivaloin Derivatives with Lithium Tetramethylpiperidide
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The reaction of lithium tetramethylpiperidide (LiTMP) with a series of derivatives of pivaloin has led to a variety of unusual transformations.The reaction of LiTMP with the triflate derivative of pivaloin (7) gave the reduced ketone 2,2,5,5-tetramethyl-3-hexanone (9), which is suggested to arise via electron transfer from LiTMP.A labeling study confirmed that α-proton abstraction from 7, giving an enolate anion, did not occur.The mesylate derivative of pivaloin (16) on treatment with LiTMP gave both isomers of 2,2,6,6-tetramethylhept-4-en-3-one (17 and 18) in which an additional carbon was incorporated into the carbon skeleton.A mechamism involving deprotonation of the methyl group of the mesyloxy function followed by intramolecular cyclization into the carbonyl function and subsequent reaction is suggested to account for this transformation.The acetate derivative of pivaloin (26) gave a cyclized product derived from proton abstraction from the methyl group of the acetoxy function, while the tosylate derivative of pivaloin (30) gave a product derived from proton abstraction from the ortho position of the aromatic ring.The α-bromo ketone 4-bromo-2,2,5,5-tetramethyl-3-hexanone (38) was reduced to ketone 9 with LiTMP.Reaction of triflate 7 and the triflate derivative of 3-hydroxycamphor (43) with potassium tert-butoxide gave the diketones 2,2,5,5-tetramethyl-3,4-hexanedione (8) and camphorquinone (44), respectively, by β elimination of trifluoromethanesulfinic acid.
- Creary, Xavier
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p. 2419 - 2425
(2007/10/02)
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