- Preparation of triacetoneamine, an improved method
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A new method for the preparation of triacetoneamine has been developed, in which, p-nitrotoluene is used as a catalyst, the yield of triacetoneamine is up to 65%.
- Wu, Anxin,Yang, Weidong,Pan, Xinfu
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Read Online
- Preparation method for synthesizing polymerization inhibitor 702 from acetone and ammonia gas through one-pot method
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The invention belongs to the technical field of polymerization inhibitor synthesis, and discloses a preparation method for synthesizing a polymerization inhibitor 702 from acetone and ammonia gas through a one-pot method. The preparation method comprises the following steps: adding acetone and a carrier catalyst into a reaction kettle, introducing ammonia gas, and conducting reacting at 50-60 DEG C for 2-6 hours; and then adding deionized water and hydrogen peroxide, conducting reacting at 15-40 DEG C for 1-3 hours, filtering the reaction solution, and carrying out reduced-pressure distillation on the obtained filtrate to obtain the polymerization inhibitor 702. According to the invention, reaction conditions are mild, the preparation method is simple and convenient, the carrier catalyst is easy to separate, and product yield is high.
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Paragraph 0027-0030; 0036; 0038-0050
(2021/04/28)
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- Method for preparing triacetone amine
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An improved method is used for preparing triacetone amine while recycling the by-products. This involves treating the crude product from triacetone amine preparation, which leads to an increase in the content of compounds which react readily with ammonia. This method enables efficient recycling of the by-products formed in the synthesis of triacetone amine.
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Paragraph 0133-0144
(2020/07/05)
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- HETEROGENEOUS CATALYZED PROCESS FOR THE PRODUCTION OF 2,2,6,6-TETRAMETHYL-4-PIPERIDONE
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The present invention relates to a process for the production of 2,2,6,6-tetramethyl-4-piperidone particularly comprising (i) providing a reactor containing a catalyst comprising a zeolitic material having a framework structure of FAU, wherein the zeolitic material comprises YO2 and X2O3 in its framework structure, wherein Y is a tetravalent element and X is a trivalent element, wherein the zeolitic material has an YO2 to X2O3 molar ratio of 16 to 175; (ii) preparing a reaction mixture comprising acetone and ammonia; (iii) contacting the catalyst in the reactor with the reaction mixture prepared in (ii) at a temperature in the range of from 40 to 250 °C for obtaining a reaction product comprising 2,2,6,6-tetramethyl-4-piperidone; wherein the mixture prepared in (ii) and contacted with the catalyst in (iii) contains less than 10 weight-% of water based on 100 weight-% of the reaction mixture.
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Page/Page column 22
(2020/12/11)
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- Method for preparing intermediate 2,2,6,6-tetramethyl-4-piperidylamine
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The invention relates to a method for preparing intermediate 2,2,6,6-tetramethyl-4-piperidylamine. The method is characterized by comprising the following steps: step 1), in the presence of a catalyst1, reacting acetone with ammonia gas to produce 2,2,6,6-tetramethyl-4-piperidinone and water; and step 2), in the presence of a catalyst 2, reacting the 2,2,6,6-tetramethyl-4-piperidinone with ammonia gas to produce 2,2,6,6-tetramethyl-4-piperidylimine and water, and reacting the 2,2,6,6-tetramethyl-4-piperidylimine with hydrogen gas to produce the 2,2,6,6-tetramethyl-4-piperidylamine, wherein the catalyst 1 is ammonium nitrate, and the catalyst 2 is a sodium hydroxyphenyl phosphate modified framework nickel catalyst. The method provided by the invention has the advantages of short synthetictime, a high conversion rate of the acetone and a high repeating utilization rate of the raw materials.
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Paragraph 0039; 0040; 0041; 00443;
(2019/12/25)
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- A 2, 2, 6, 6 - tetramethyl -4 - piperidone preparation method (by machine translation)
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The invention provides a 2, 2, 6, 6 - tetramethyl - 4 - piperidone of preparation method, include acetone with a disaccharide modified UiO - 66 catalyst is added to the reaction in the device, in order to acetone with ammonia (3 - 12): 1 molar ratio of the ammonia gas, in the 50 - 80 °C reaction, after the reaction, the temperature, pressure, filtering, rectification to get 2, 2, 6, 6 - tetramethyl - 4 - piperidone; the invention also provides a method for the preparation of the sulfonic acid-modified with the appropriate Acid with the channel pore size of the metal-organic framework material of the novel catalyst and its application. The method of the invention with green, economic and high efficiency, at the same time the catalyst of the invention shows excellent stability and selectivity. (by machine translation)
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Paragraph 0052-0062; 0065-0070; 0071-0076; 0077-0088
(2018/05/16)
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- Secondary Phosphine Oxides as Multitalented Preligands En Route to the Chemoselective Palladium-Catalyzed Oxidation of Alcohols
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Secondary phosphine oxides O=PHR2 (SPOs) were identified as multitalented preligands for the chemoselective Pd-catalyzed oxidation of alcohols by a hydrogen-abstracting methodology. SPOs were found to promote the hydrogen-abstraction step as well as hydrogen transfer to a Michael acceptor by generating a putative active H?Pd species. The catalytic system operates under neutral conditions and was proven to be compatible with various electrophilic and nucleophilic functionalities within the substrates as well as water- and air-sensitive functional groups.
- Vasseur, Alexandre,Membrat, Romain,Gatineau, David,Tenaglia, Alphonse,Nuel, Didier,Giordano, Laurent
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p. 728 - 732
(2017/03/13)
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- A 2, 2, 6, 6-tetramethyl-4-PIPERIDYLAMINES method for the preparation of
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The invention discloses a method for preparing 2,2,6,6-tetramethyl-4-piperidinamine. The method comprises the following steps: synthesizing 2,2,6,6-tetramethyl-4-piperidone and carrying out a hydrogenation reaction of the 2,2,6,6-tetramethyl-4-piperidone. The key synthesis steps are controlled, the addition amount for acetone recovery is controlled, and the rectification purity and conversion rate of the product are improved through the optimized distillation, crystallization and hydrogenation reduction process.
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Paragraph 0028-0036
(2017/04/11)
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- Effect of Alkali Treatment of HY Zeolite on Continuous Synthesis of Triacetonamine
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The continuous synthesis of triacetonamine from acetone and ammonia over HY was realized. Meanwhile, alkali-treated HY with different structure and acidities were prepared and examined. The results indicated that the acid sites, especially Br?nsted acid sites, played a vital role on the selectivity of triacetonamine and the conversion of acetone. It was further confirmed by X-ray diffraction (XRD), N2 adsorption and desorption experiments, IR spectra of adsorbed pyridine, and NH3 temperature-programmed desorption. Meanwhile, the generation mechanisms of triacetonamine and impurities were speculated.
- Tian, Jun,Chen, Ligong,Zhang, Chao,Yan, Xilong,Li, Yang
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p. 1377 - 1381
(2015/02/19)
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- Continuous synthesis of triacetonamine over cation-exchange resin
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A continuous process for the synthesis of triacetonamine, which is the sole precursor of most hindered amine light stabilizers, from acetone and ammonia was carried out with NKC-9 cation-exchange resin in a fixed bed reactor. The plausible reaction mechanism was also discussed. The effect of different reaction parameters including molar ratio of reactants, gas hour space velocity and reaction temperature have been investigated to obtain the optimal conditions. The activity, selectivity and stability of the catalyst were demonstrated and a continuous process for production of triacetonamine from acetone and ammonia has been established.
- Du, Xiaobao,Song, Ge,Tian, Jun,Li, Yang
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p. 541 - 543
(2015/03/03)
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- METAL AMIDES OF CYCLIC AMINES
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Compounds, and oligomers of the compounds, are synthesized with cyclic amine ligands attached to a metal atom. These compounds are useful for the synthesis of materials containing metals. Examples include pure metals, metal alloys, metal oxides, metal nitrides, metal phosphides, metal sulfides, metal selenides, metal tellurides, metal borides, metal carbides, metal silicides and metal germanides. Techniques for materials synthesis include vapor deposition (chemical vapor deposition and atomic layer deposition), liquid solution methods (sol-gel and precipitation) and solid-state pyrolysis. Suitable applications include electrical interconnects in microelectronics and magnetoresistant layers in magnetic information storage devices. The films have very uniform thickness and high step coverage in narrow holes.
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Paragraph 0058; 0060
(2015/02/19)
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- Selective synthesis of dimethyl ketone oxime through ammoximation over Ti-MOR catalyst
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Titanosilicate with the MOR topology (Ti-MOR), postsynthesized from highly dealuminated mordenite and TiCl4 vapor through a solid–gas reaction, was highly active and selective for the liquid-phase ammoximation of dimethyl ketone (DMK) with ammonia and hydrogen peroxide. The parameters effecting the formation of the ammoximation product of dimethyl ketone oxime were investigated systematically in a batch-type reactor, and the optimized conditions were further applied to continuous ammoximation of DMK in a slurry reactor. Ti-MOR was superior to other titanosilicates in terms of activity and lifetime. TS-1 was not suitable for the ammoximation of DMK, whereas Ti-MWW required a higher catalyst loading to reach a reasonable activity, and they both easily produced a main byproduct of oxidative coupling of dimethyl ketone oxime. The deactivation behavior of Ti-MOR was investigated. Ammonia-induced structural desilication and accompanied Ti sites migration altered a more serious influence on the catalyst duration than coke deposition during continuous ammoximation.
- Ding, Jianghong,Wu, Peng
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- Towards a more sustainable production of triacetoneamine with heterogeneous catalysis
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The acid-catalyzed condensation of acetone and ammonia to directly produce 2,2,6,6-tetramethy-4-piperidone (triacetonamine) was studied under both homogeneous and heterogeneous catalysis. The selectivity to the desired product was affected by the presence of a complex reaction network involving several kinetically parallel and consecutive reactions, leading to by-products such as diacetonealcohol, diacetoneamine, mesityl oxide, acetonine, and 2,2,4,6-tetramethyl-2,5-dihydropyridine. The latter was the most undesired by-product, since its formation was irreversible. Key elements in achieving high selectivity in the direct synthesis of triacetonamine were the molar feed ratio between acetone and ammonia, and the amount of water in the reaction medium; in fact, water was found to play an important role in the transformation of the intermediate acetonine into triacetonamine. Compared with homogeneous catalysis, the selectivity achieved by the use of the heterogeneous H-Y zeolites was controlled by means of a proper selection of the zeolite features. In fact, the use of a highly hydrophilic H-Y zeolite made it possible to achieve the same selectivity as that obtained under homogeneous catalysis conditions, with the additional advantage of using an easily separable and reusable catalyst, which showed no deactivation.
- Gliozzi, Gherardo,Frattini, Lucia,Righi, Paolo,Cavani, Fabrizio
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p. 325 - 332
(2014/08/18)
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- Continuous synthesis of triacetonamine over sulfonic acid-functionalized mesoporous silicas
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The continuous synthesis of triacetonamine from acetone and ammonia was realized over sulfonic acid-functionalized mesoporous silicas. These catalysts were characterized by TG, XPS, BET, elemental analysis and acid-base titration. The results indicated th
- Tian, Jun,Chen, Ligong,Zhang, Chao,Yan, Xilong,Li, Yang
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p. 17860 - 17865
(2014/05/06)
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- The mechanism of catalyst deactivation and by-product formation in acetone ammoximation catalyzed by hollow titanium silicalite
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The deactivation mechanism of hollow titanium silicalite (HTS) in aqueous ammoximation of acetone was investigated. Amines and polynitro-compounds, formed by alkaline autocatalytic and oxidative coupling reaction respectively, were determined to be the ma
- Wang, Yi,Zhang, Shengjian,Zhao, Yingxian,Lin, Min
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- Two-step synthesis and biological evaluation of calyxamines A and B
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A two-step synthesis of naturally occurring alkaloids calyxamines A and B featuring a tandem Mannich–aldol condensation reaction under solvent free conditions, and their inhibitory activity against acetylcholinesterase (AChE) is reported.
- Meza-León, Rosa-L.,García, Alvaro Dávila,Sartillo-Piscil, Fernando,Quintero, Leticia,Rivadeneyra, Martha Sosa,Cruz-Gregorio, Silvano
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p. 6852 - 6854
(2019/04/10)
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- Synthesis of triacetonamine N-alkyl derivatives reinvestigated
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The N-alkylated 2,2,6,6-tetramethylpiperidin-4-ones 3c-f were prepared from the acetal 6a of triacetonamine (3a) by alkylation followed by hydrolysis of the acetal functionality or alternatively from the corresponding secondary alcohol 2,2,6,6-tetramethyl
- Banert, Klaus,Fink, Katharina,Hagedorn, Manfred,Richter, Frank
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p. 379 - 390
(2013/09/24)
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- Rapid aerobic oxidation of alcohols to carbonyl compounds with dioxygen using metallodeuteroporphyrin dimethyl esters as catalysts in the presence of isobutylaldehyde
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A facile biomimetic method for rapid oxidation of alcohols to carbonyl compounds using dioxygen as the primary oxidant catalyzed by metallodeuteroporphyrin dimethyl ester [M(DPDME)] in acetonitrile as the reaction solvent and isobutylaldehyde as cocatalyst has been investigated. Among the M(DPDME) catalysts, where M = Fe(III), Co(II), Mn(III), Ni(II), Cu(II), and Zn(II), cobalt porphyrin was found to be the most active and effective catalyst. The catalytic system was widely used in the oxidation of various alcohols and especially exhibited excellent activity for oxidation of aromatic alcohols under mild conditions. Moreover, M(DPDME) was prepared from an improved facile method by chemical modification of natural hemin and an alternative mechanism for the aerobic oxidation of alcohols has been proposed and discussed.
- Sun, Chengguo,Hu, Bingcheng,Liu, Zuliang
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experimental part
p. 295 - 303
(2012/07/28)
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- Reactions of nitroxides. Part X: Antifungal activity of selected sulfur and selenium derivatives of 2,2,6,6-tetramethylpiperidine
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The antifungal activity of nitroxyl radicals - derivatives of 2,2,6,6-tetramethylpiperidine-1-oxyl with reactive substituents 4-isothiocyanato-, 4-isocyano-, and 4-isoselenocyanato- and of N-formyl-, N-thioformyl-, N-selenoformyl-derivatives of 2,2,6,6-tetramethylpiperidine was investigated. Those of the above compounds, which contain a sulfur or selenium atom are the most active against four fungus plant patogens: Botrytis cinerea, Fusarium culmorum, Phytophthora cactorum, Rhizoctonia solani. 4-Isoselenocyanato-2,2,6,6-tetramethylpiperidine-1-oxyl proved to be the most active compound.
- Zakrzewski, Jerzy,Krawczyk, Maria
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scheme or table
p. 514 - 516
(2011/02/28)
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- The synthesis of EPR differentiable spinlabels and their coupling to uridine
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For EPR measurements of RNA, DNA, or proteins, the occurrence of the paramagnetic species is necessary. The aim of this work is to improve the synthesis of two different EPR spinlabels 2,2,6,6-tetra methyl-3,4-dehydro- piperidin-N-oxyl-4-acetylene (TEMPA) 6 and 15N-labeled TEMPA 6* and their coupling to uridine. The yield of the synthesis of TEMPA could be increased to 40% and the second nitroxide 2,2,6,6-tetramethyl-3,4-dehydro-piperidin-15N-oxyl- 4-acetylene 6* could be synthesized with a yield of 11%. Copyright Taylor & Francis Group, LLC.
- Frolow, Olga,Bode, Bela E.,Engels, Joachim W.
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p. 655 - 659
(2008/09/17)
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- Method for preparing nitroxides
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The invention concerns a method for preparing nitroxides, which consists in oxidising, in a two-phase medium, using an aliphatic peroxide, secondary amines with steric hindrance or having a —CH in the nitrogen atom α.
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- 15N NMR spectroscopy of labeled alkoxyamines. 15N-labeled model compounds for nitroxide-trapping studies in free-radical (Co)polymerization
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Eight 15N-labeled derivatives of 1-ethoxy-2,2,6,6-tetramethylpiperidine were synthesized in order to investigate the effects of their structural units on 15N NMR spectra. A single peak is found for each alkoxyamine. The chemical shift depends extensively on the nature of the α carbon atom of the alkoxy group. The remote functional group attached to position 4 of the piperidine ring has a smaller but still significant effect. The results of the 15N NMR measurements are supported by the detection of the N-H and N-C spin-spin coupling from the 1H and 13C NMR. The investigated alkoxyamines are model compounds for the radical-trapping products of styryl, methyl methacryloyl, α-methylstyryl, and methyl acryloyl radicals by 15N-labeled nitroxides. The potential of 15N NMR spectroscopy to analyze such products is discussed. In addition, it is shown that the 13C chemical shifts of the α carbon atom of the alkoxy group fall in an empty part of the 13C NMR spectrum, which allows the identification of trapped (macro)radicals via natural abundance 13C NMR.
- Kelemen, Peter,Lugtenburg, Johan,Klumperman, Bert
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p. 7322 - 7328
(2007/10/03)
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- Crowded piperidines with intramolecularly hydrogen-bonded nitrogen: Synthesis and conformation study
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2,2,6,6-Tetramethyl substituted piperidines with a β-branched N-alkyl substituent were synthesized by the photoreaction of N-Me precursors with ketones. The main conformation features of these sterically-hindered amines (established by NMR and IR spectroscopy) are a ring in the chair form, an eclipsed conformation for the N-substituent and an intramolecular OH···N bond. High barriers for the geminal substituent topomerization were measured for these piperidines at different temperatures by means of line-shape analysis of the temperature-dependent 13C and 1H NMR spectra. An MM3-derived conformation scheme indicated that, for one of the studied analogues, the rotation of the N-substituent determines a slow topomerization rate. A new mechanism of nitrogen inversion - a concerted hydrogen-bond dissociation/nitrogen inversion process - is considered for hydrogen-bonded amines.
- Belostotskii, Anatoly M.,Gottlieb, Hugo E.,Aped, Pinchas
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p. 3016 - 3026
(2007/10/03)
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- Oxoammonium Salts. 5. A New Synthesis of Hindered Piperidines Leading to Unsymmetrical TEMPO-Type Nitroxides. Synthesis and Enantioselective Oxidations with Chiral Nitroxides and Chiral Oxoammonium Salts
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A new synthesis of unsymmetrical 2,2,6,6-tetraalkyl-4-piperidones from acetonin (2,2,4,4,6-pentamethyl-2,3,4,5-tetrahydropyrimidine) and several ketones is described.When the ketone was a naturally occurring optically active ketone, the piperidones were optically active.The piperidones were converted to unsymmetrical TEMPO-type nitroxides and chiral nitroxides.The optically active nitroxides were used as catalysts for oxidations or converted to chiral oxoammonium salts.The structures of the chiral compounds were determined by 2D (1)H and (13)C NMR, and the cyclic voltammetric properties of the various nitroxides were measured.Several other pyrrolidine oxoammonium salts were prepared, and both types were used as oxidizing agents.Preliminary results of chiral oxidations are presented.
- Ma, Zhenkun,Huang, Qingtao,Bobbitt, James M.
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p. 4837 - 4843
(2007/10/02)
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- Nitroxide NMR contrast enhancing agents and their use in NMR imaging
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Nitroxides useful as NMR contrast enhancing agents for organs are of the formula STR1 wherein in the above formulae, R1, R2, R3 and R4 are, g., CH3 ; R is --B--COO--M+ or --B--N(alkyl)3 Hal-, wherein B is a divalent bond or alkylene of 1-8 carbon atoms, M is an ammonium or metal ion and Hal is a halogen atom; are also useful as NMR contrast enhancing agents on joints.
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- A Reaction of Nitroxides with Ethyl Mercaptane: A Mild Method for the Conversion of Nitroxides into Their Corresponding Amines
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The mild reduction of the nitroxides 1a-j to the corresponding sterically hindered amines 2a-j by means of ethyl mercaptane is reported.The reaction mixtures of 1a,b,g were analyzed by glc/ms.
- Zakrzewski, Jerzy
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p. 803 - 808
(2007/10/02)
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- Hindered piperidyl light stabilizers
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Piperidine-4-carboxylic acid derivatives of the formula STR1 wherein: R2 is hydrogen, alkyl having from one to four carbon atoms, or oxyl; R3 is --XR5 or --CN; R4 is alkylene having from two to twelve carbon atoms; cycloalkylene having from three to twelve carbon atoms; arylene having from six to twelve carbon atoms; or aralkylene having from seven to twelve carbon atoms; R5 is hydrogen, alkyl having from one to twenty carbon atoms, cycloalkyl having from five to six carbon atoms; or alkenyl having from three to twenty carbon atoms; or STR2 X is --O-- or --NH--; and n is 0 to 10; and the acid addition salts thereof.
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- Process for the preparation of 2,2,6,6-tetramethylpiperidone-4
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In the synthesis of 2,2,6,6-tetramethylpiperidone-4 (triacetone-amine) from acetone and ammonia, a partially halogenated or perhalogenated aliphatic or cyclic hydrocarbon is used as catalyst in an amount of from 0.01 to 5 mol %, relative to acetone.
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- Process for the preparation of 2,2,6,6-tetramethyl-4-oxopiperidine
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2,2,6,6-Tetramethyl-4-oxopiperidine is prepared from 2,2,4,4,6-pentamethyl-2,3,4,5-tetramethylpyrimidine (acetonine) by heating in the presence of acetone, diacetone alcohol or water. These regents may be used in excess or an organic solvent is added. The preferred modification is the heating of acetonine hydrate in an excess of acetone or in an acetone-methanol mixture to about 40° to 65°C for several hours. The use of diacetone alcohol permits higher reaction temperatures leading to shorter reaction times.
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- Process for the preparation of 2,2,6,6-tetramethyl-4-oxopiperidine
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2,2,6,6-Tetramethyl-4-oxopiperidine is prepared from acetone and ammonia in the presence of acidic catalysts. Suitable catalysts are Lewis acids, protionic acids and their salts with ammonia or with organic bases, as for example BF3, NH4 Cl or H2 SO4. The addition of an alcohol such as methanol as well as the use of a cocatalyst may promote the reaction. The process may be carried out in two steps, in the first of which the temperature is held below 35°C. In the second step a further amount of acetone is added and the temperature is rised to about 40° to 65°C.
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- Process for the preparation of 2,2,6,6-tetramethyl-4-oxopiperidine
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2,2,6,6-Tetramethyl-4-oxopiperidine is prepared from 2,2,4,4,6-pentamethyl-2,3,4,5-tetrahydropyrimidine by treatment with an acidic catalyst. Suitable catalysts are Lewis acids, protonic acids and their salts with ammonia or organic bases. The reaction may be carried out in organic solvents, preferably in acetone, by gentle heating, for example at 40° to 65°C. Yields of 95% are obtainable after a reaction of several hours.
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