- Ring contraction of N-acetyl-2-aryl-1,2,3,4-tetrahydro-4-quinolones with [hydroxy(tosyloxy)iodo]benzene to trans methyl N-acetyl-2-aryl-2,3-dihydroindol- 3-carboxylates
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The ring contraction of N-acetyl-2-aryl-1,2,3,4-tetrahydro-4-quinolones with [hydroxy(tosyloxy)iodo]benzene to trans methyl N-acetyl-2-aryl-2,3- dihydroindol-3-carboxylates in trimethylorthoformate in good yield is described.
- Kumar, Ashok,Kumar, Sunil,Gupta, Rakesh K.,Kumar, Devinder
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Read Online
- Iron(III)-Mediated Oxysulfonylation of Enamides with Sodium and Lithium Sulfinates
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An iron-mediated vicinal difunctionalization of enamides and enecarbamates with sulfinic acid salts and alcohols is described. This reaction proceeds under mild conditions and furnishes the oxysulfonylated products in moderate to excellent yields. Moreover, the direct incorporation of sulfur dioxide into the sulfonylated products via organolithium chemistry has been achieved. The formed N-O-acetals are competent acylimine precursors. Their utilization as building blocks for the synthesis of biologically relevant β-amidosulfones is described as well.
- Halaczkiewicz, Miro,Kelm, Harald,Kramer, Philipp,Manolikakes, Georg,Sun, Yu
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Read Online
- Grob-type fragmentation of 5-oxabicyclo[2.1.1]hexane system: A strategy for synthesis of annulated and 2,2,5-trisubstituted tetrahydrofurans
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Acid mediated, efficient Grob-type fragmentation reaction facilitated by vicinal ketal and ester moieties in variety of 5-oxabicyclo[2.1.1]hexanes leading to the corresponding annulated and 2,2,5-trisubstituted tetrahydrofurans is reported. Among the Br?nsted and Lewis acids tested, BF 3·OEt2 appears to give the best results, furnishing near quantitative yield (>99%) of tetrahydrofuran tricarboxylate derivatives under mild reaction condition. In case of unsymmetrical monosubstituted 5-oxabicyclo[2.1.1]hexanes two regioisomeric products are obtained. A strategy to transform one of the ester groups of the title compounds to protected hydroxymethyl moiety was evolved, which allows access to differentially protected 2-hydroxymethyl THF derivatives upon fragmentation. Employing TiCl4/R or S-BINOL as chiral Lewis acid, an enantioselective fragmentation (up to 66% ee) was described for the meso bis-furan derivative.
- Mahadevegowda, Surendra H.,Khan, Faiz Ahmed
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Read Online
- Method for the Preparation of Diamine Derivative
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The present invention relates to high yield. The present invention relates to a process for preparing high purity ethaboxate p - toluenesulphonate or hydrates thereof. To the present invention, generation of a dielectric toxic substance and a side reaction product can be suppressed, and high yield, high purity of edoxaba p - toluenesulphonate or a hydrate thereof can be advantageously used.
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Paragraph 0284-0288
(2021/03/23)
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- A Scalable Metal-, Azide-, and Halogen-Free Method for the Preparation of Triazoles
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A scalable metal-, azide-, and halogen-free method for the synthesis of substituted 1,2,3-triazoles has been developed. The reaction proceeds through a 3-component coupling of α-ketoacetals, tosyl hydrazide, and a primary amine. The reaction shows outstanding functional-group tolerance with respect to both the α-ketoacetal and amine coupling partners, providing access to 4-, 1,4-, 1,5-, and 1,4,5-substituted triazoles in excellent yield. This robust method results in densely functionalised 1,2,3-triazoles that remain challenging to prepare by azide–alkyne cycloaddition (AAC, CuAAC, RuAAC) methods and can be scaled in either batch or flow reactors. Methods for the chemoselective reaction of either aliphatic amines or anilines are also described, revealing some of the potential of this novel and highly versatile transformation.
- Clark, Peter R.,Hayes, Jerome F.,Tomkinson, Nicholas C. O.,Williams, Glynn D.
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p. 6740 - 6744
(2020/03/23)
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- 6MNEP: A molecular cation with large hyperpolarizability and promise for nonlinear optical applications
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Molecular organic crystals are strategically designed for nonlinear optical applications using push-pull chromophores as the core feature. In this approach, electron-donating and accepting groups are connected through a π-conjugated bridge to obtain planar molecules with high hyperpolarizability. However, the non-centrosymmetric packing that is required for nonlinear optical (NLO) applications is a critical challenge that must be addressed to design useful materials. In this article, we present the new organic cation 6MNEP that shows a large hyperpolarizability and can be crystallized in ideal non-centrosymmetric structures for NLO applications, when paired with T and 4NBS anions. The 6MNEP cation was obtained by extending the conjugation length of already existing chromophores. We compare the 6MNEP crystals with other crystals that also have cations with extended conjugation lengths, but result in centrosymmetric crystal structures. Using the effective hyperpolarizability, we found 6MNEP-T and 6MNEP-4NBS to have 1.6 to 2.5 times larger macroscopic nonlinearities than benchmark NLO organic crystals. Additionally, the significantly lower absorption wavelength compared with other state-of-the-art crystals make 6MNEP-T and 6MNEP-4NBS promising materials for NLO applications like intense terahertz generation.
- Bloxham, Joseph C.,Brock, Daniel J.,Jackson, Erika W.,Johnson, Jeremy A.,Kenney, Karissa C.,Michaelis, David J.,Smith, Stacey J.,Valdivia-Berroeta, Gabriel A.,Wayment, Adam X.
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supporting information
p. 11079 - 11087
(2020/09/09)
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- A simple method for the synthesis of sulfonic esters
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An efficient and simple approach for the direct synthesis of aryl and heteroaryl sulfonic esters was developed using DMS and DES as alkoxysulfonylation reagents. The reaction is operationally simple and scalable. This protocol does not require solvent, expensive catalysts, base, ligand additives or other reagents. A wide range of sulfonic esters were synthesized in moderate to good chemical yields. This method has the advantage of low cost, facile and tolerated a wide range of substrates.
- Bhatthula, Bharath Kumar Goud,Kanchani, Janardhan Reddy,Arava, Veera Reddy,Marata Chenna Subbarao, Subha
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supporting information
p. 1 - 16
(2020/07/27)
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- Design and Optimization of a Continuous Stirred Tank Reactor Cascade for Membrane-Based Diazomethane Production: Synthesis of α-Chloroketones
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The development of a continuous diazomethane generator comprising a continuous stirred tank reactor (CSTR) cascade and membrane separation technology is reported. This reactor concept was applied for the telescoped three-step synthesis of a chiral α-chloroketone, a key building block for many HIV protease inhibitors, via a modified Arndt-Eistert reaction starting from N-protected l-phenylalanine. The initial mixed anhydride was generated in a coil reactor and directly introduced into the CSTR diazomethane cascade. The use of a semipermeable Teflon membrane (AF-2400) allowed the generation of anhydrous diazomethane, which diffuses through the membrane into the CSTR where it is immediately consumed by the anhydride to furnish the corresponding diazoketone. The subsequent halogenation with concentrated HCl was performed downstream in batch and allowed production of the α-chloroketone on a multigram scale, with a productivity of 1.54 g/h (5.2 mmol/h).
- Wernik, Michaela,Poechlauer, Peter,Schmoelzer, Christoph,Dallinger, Doris,Kappe, C. Oliver
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supporting information
p. 1359 - 1368
(2019/08/12)
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- Rapid transformation of sulfinate salts into sulfonates promoted by a hypervalent iodine(III) reagent
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An alternative method for forming sulfonates through hypervalent iodine(III) reagent-mediated oxidation of sodium sulfinates has been developed. This transformation involves trapping reactive sulfonium species using alcohols. With additional optimization of the reaction conditions, the method appears extendable to other nucleophiles such as electron-rich aromatic systems or cyclic ethers through a ring opening pathway.
- Deruer, Elsa,Hamel, Vincent,Blais, Samuel,Canesi, Sylvain
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supporting information
p. 1203 - 1207
(2018/06/04)
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- Methacetin preparation method
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The invention discloses a methacetin preparation method. The preparation method comprises the steps of adding p-toluenesulfonyl chloride or p-toluenesulfonic acid, anhydrous methanol, a solvent and the like into a reactor, dropwise adding a reagent at a controlled temperature, monitoring the reaction, performing quenching, extracting, washing, drying, reduced-pressure filtering and concentrating to obtain an intermediate, then performing methylation to obtain a crude solid product of methacetin, and finally performing refining to obtain a white crystalline product of methacetin. Compared withconventional production technology and process, the synthesis and refining methods of the invention generate methacetin with less impurities and higher purity, and improve the product quality and theaccuracy of test results using the reagent methacetin.
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Paragraph 0020; 0023
(2018/05/30)
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- Copper-Catalyzed Multicomponent Reaction of DABCO·(SO2)2, Alcohols, and Aryl Diazoniums for the Synthesis of Sulfonic Esters
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A Cu-catalyzed multicomponent cascade reaction of DABCO·(SO2)2 (DABSO), alcohol, and aryl diazonium tetrafluoroborate was developed which afforded sulfonic esters in moderate to good chemical yields. In this reaction, the SO2 surrogate DABSO was used for the first time in the synthesis of sulfonic aliphatic esters. This multicomponent reaction was carried out under mild conditions and tolerated a wide range of substrates, which provides a new and efficient strategy for the synthesis of sulfonic esters.
- Wang, Yang,Deng, Lingling,Deng, Yu,Han, Jianlin
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p. 4674 - 4680
(2018/04/26)
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- Photoinduced Oxidative Cross-Coupling for O-S Bond Formation: A Facile Synthesis of Alkyl Benzenesulfonates
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We have developed a photoinduced oxidative cross-coupling of thiophenols with alcohols for O-S bond formation. The protocol uses visible light, a metal-free photocatalyst, and oxygen as the oxidant for the selective synthesis of alkyl benzenesulfonates; no ligand co-additive is necessary. Mechanistic studies suggested that the disulfide and alkyl benzenesulfinate are involved as intermediates and that the transformation proceeds by a radical pathway.
- Singh, Atul K.,Yi, Hong,Zhang, Guoting,Bian, Changliang,Pei, Pengkun,Lei, Aiwen
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supporting information
p. 1558 - 1563
(2017/08/11)
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- Perfluoroalkanesulfonylation of Alkynyl(phenyl)iodonium Tosylates by the Weakly Nucleophilic Sodium Perfluoroalkanesulfinates
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An additive- and transition metal-free perfluoroalkanesulfonylation of alkynyl(phenyl)iodonium tosylates with sodium perfluoroalkanesulfinates (RfnSO2Na) is described. The poorly nucleophilic RfnSO2Na reacted with alkynyl(phenyl)iodonium salts in dichloromethane at room temperature under a nitrogen atmosphere for 5–60 minutes to afford a variety of acetylenic triflones and alkynyl perfluoroalkyl sulfones in good to quantitative yields. The position of substituents on the phenyl rings of the arylethynyl moiety in the iodonium salts had a big influence on the reaction. The formation of five-membered cyclic vinyl sulfones suggested that the reaction proceeds via an alkylidene carbene intermediate. Furthermore, successful scaling-up of the reaction demonstrates the practicality of the new method. Advantages of the method include short reaction times, mild conditions, and the easy access to perfluoroalkanesulfonylation reagents (RfnSO2Na). (Figure presented.).
- Han, Jia-Bin,Yang, Lian,Chen, Xing,Zha, Gao-Feng,Zhang, Cheng-Pan
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supporting information
p. 4119 - 4124
(2016/12/30)
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- Synthetic method of selective methylation reagent methyl p-toluenesulfonate
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Disclosed is a synthetic method of selective methylation reagent methyl p-toluenesulfonate. The synthetic method is characterized by including the following steps: (i) adding 0.271mol of p-toluenesulfonyl bromine (2) into a reaction vessel provided with a stirrer, a temperature gauge and a dropping funnel and 1.57-1.59mol of 2,2,2-trifluoroethyl methyl ether, controlling the stirring rate at 160-190rpm, controlling the solution temperature at 35-40 DEG C, dropwise adding 300ml of potassium carbonate solution with the time of dropwise adding controlled to be 2-3h, maintaining the stirring state for 5-6h after addition, separating an oil layer, sequentially washing with saline solution, sodium sulfite solution and dimethylamine solution, dehydrating with a dehydrating agent, performing reduced pressure distillation, and collecting distillate at the temperature of 140-145 DEG C to obtain methyl p-toluenesulfonate (1), wherein the mass fraction of the potassium carbonate solution is 45-50%, and the saline solution in the step (i) is any one of potassium bromide and sodium chloride.
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Paragraph 0015; 0016
(2016/11/24)
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- METHOD FOR PRODUCING SULFONYL CHLORIDE COMPOUNDS
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PROBLEM TO BE SOLVED: To provide a production method which enables safe and simple production of sulfonyl chloride compounds in high yields, which are useful as intermediates for medicines, agrochemicals, functional materials, and the like. SOLUTION: Provided is a method for producing sulfonyl chloride compounds comprising oxidation of thiols or disulfides in the presence of an oxidizing agent to produce sulfonyl chloride compounds. As the oxidizing agent is used sodium hypochlorite, and the reaction is performed with the pH of the reaction system adjusted to a neutral or acidic value of pH 7 or less. COPYRIGHT: (C)2015,JPOandINPIT
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Paragraph 0034
(2018/11/22)
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- Oxidative umpolung ?±-alkylation of ketones
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We disclose a hypervalent iodine mediated ?±-alkylative umpolung reaction of carbonyl compounds with dialkylzinc as the alkyl source. The reaction is applicable to all common classes of ketones including 1,3-dicarbonyl compounds and regular ketones via their lithium enolates. The ?±-alkylated carbonyl products are formed in up to 93% yield. An ionic mechanism is inferred based on meticulous analysis, NMR studies, trapping and crossover experiments, and computational studies.
- Shneider, O. Svetlana,Pisarevsky, Evgeni,Fristrup, Peter,Szpilman, Alex M.
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supporting information
p. 282 - 285
(2015/03/05)
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- Facile Synthesis of 2,5-Disubstituted Thiazoles from Terminal Alkynes, Sulfonyl Azides, and Thionoesters
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A sequential procedure for the synthesis of 2,5-disubstituted thiazoles from terminal alkynes, sulfonyl azides, and thionoesters is reported. A copper(I)-catalyzed 1,3-dipolar cycloaddition of terminal alkynes with sulfonyl azides affords 1-sulfonyl-1,2,3-triazoles, which then react with thionoesters in the presence of a rhodium(II) catalyst. The resulting 3-sulfonyl-4-thiazolines subsequently aromatize into the corresponding 2,5-disubstituted thiazoles by elimination of the sulfonyl group. (Chemical Equation Presented).
- Miura, Tomoya,Funakoshi, Yuuta,Fujimoto, Yoshikazu,Nakahashi, Junki,Murakami, Masahiro
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supporting information
p. 2454 - 2457
(2015/05/27)
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- An efficient method for the preparation of sulfonyl chlorides: Reaction of disulfides or thiols with sodium hypochlorite pentahydrate (NaOCl·5H2O) crystals
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The reaction of disulfides or thiols with sodium hypochlorite pentahydrate in acetic acid efficiently provided the corresponding sulfonyl chlorides in high yields.
- Okada, Tomohide,Matsumuro, Hiroaki,Iwai, Toshiaki,Kitagawa, Saori,Yamazaki, Kento,Akiyama, Tomomi,Asawa, Tomotake,Sugiyama, Yukihiro,Kimura, Yoshikazu,Kirihara, Masayuki
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p. 185 - 187
(2015/02/19)
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- Carbohydrate and polyol ethers as renewable oils, greases, and liquid fuels
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Alkyl ethers are produced directly from polyols or their salts in a single step reaction, or alternatively, the polyols are first converted to a ketal or acetal derivative which comprises at least one free hydroxyl moiety and one or more ketal or acetal moieties. In either embodiment, the polyol, its salt, or its ketal or acetal derivative is reacted with an alkylating agent to produce a first alkoxy polyol ether comprising one or more alkoxy moieties formed at the sites of the free hydroxyl moieties. Ethers prepared from the polyol ketal or acetal derivatives retain their ketal or acetal moieties, which may be hydrolyzed to additional free hydroxyls and reacted with alkylating agent to produce a second alkoxy polyol ether. Alkyl tosylates are preferred alkylating agents. The spent alkylating agents may also be recovered and regenerated. Recovered alkoxy polyol ethers may be used as renewable fuels, solvents and lubricants.
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Page/Page column 6
(2014/05/20)
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- Efficient, scalable and economical preparation of tris(deuterium)- and 13C-labelled N-methyl-N-nitroso-p-toluenesulfonamide (Diazald) and their conversion to labelled diazomethane
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A method for the preparation of multi-gramme quantities of N-methyl-d3-N-nitroso-p-toluenesulfonamide (Diazald-d3) and N-methyl-13C-N-nitroso-p-toluenesulfonamide (Diazald-13C) and their conversion to diazomethane-d2 and diazomethane-13C, respectively, is presented. This approach uses robust and reliable chemistry, and critically, employs readily commercially available and inexpensivemethanol as the label source. Several reactions of labelled diazomethane are also reported, including alkene cyclopropanation, phenolmethylation and α-diazoketone formation, as well as deuteriumscrambling in the preparation of diazomethane-d2 and subsequent methyl esterification of benzoic acid.
- Shields, Samuel W.J.,Manthorpe, Jeffrey M.
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p. 674 - 679
(2015/01/16)
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- Design, synthesis, and biological evaluation of deuterated C-aryl glycoside as a potent and long-acting renal sodium-dependent glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes
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SGLT2 inhibitors deuterated at sites susceptible to oxidative metabolism were found to have a slightly longer tmax and half-life (t 1/2), dose-dependent increase in urinary glucose excretion (UGE) in rats, and slightly superior effects on UGE in dogs while retaining similar in vitro inhibitory activities against hSGLT2. In particular, deuterated compound 41 has the potential to be a robust long-acting antidiabetic agent.
- Xu, Ge,Lv, Binhua,Roberge, Jacques Y.,Xu, Baihua,Du, Jiyan,Dong, Jiajia,Chen, Yuanwei,Peng, Kun,Zhang, Lili,Tang, Xinxing,Feng, Yan,Xu, Min,Fu, Wei,Zhang, Wenbin,Zhu, Liangcheng,Deng, Zhongping,Sheng, Zelin,Welihinda, Ajith,Sun, Xun
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p. 1236 - 1251
(2014/03/21)
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- Regioselective C 2 sulfonylation of indoles mediated by molecular iodine
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A facile and general method for regioselective C2 sulfonylation reaction of indoles mediated by iodine is described. The 2-sulfonylated products were obtained up to 96% yield under mild reaction conditions (room temperature, 2 h).
- Katrun, Praewpan,Mueangkaew, Charoensak,Pohmakotr, Manat,Reutrakul, Vichai,Jaipetch, Thaworn,Soorukram, Darunee,Kuhakarn, Chutima
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p. 1778 - 1785
(2014/03/21)
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- Synthesis of optically pure 3,3′-diaryl binaphthyl disulfonic acids via stepwise N-S bond cleavage
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We developed a practical synthesis of optically pure 3,3′-diaryl-1, 1′-binaphthyl-2,2′-disulfonic acids (i.e., (R)- or (S)-3,3′-Ar2-BINSAs) from the parent chiral sulfonimides via stepwise N-S bond cleavage of the sulfonimides and the resultant sulfonamides. This unusual synthesis, which provides arylsulfonic acids from arylsulfonamides, is valuable since common methods particularly give amines with the decomposition of sulfone groups during deprotection.
- Hatano, Manabu,Ozaki, Takuya,Nishikawa, Keisuke,Ishihara, Kazuaki
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p. 10405 - 10413
(2013/11/06)
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- Copper-catalyzed cross-coupling reaction of organoboron compounds with primary alkyl halides and pseudohalides
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Non-activated alkyl electrophiles, including alkyl iodides, bromides, tosylates, mesylates, and even chlorides, underwent copper-catalyzed cross-coupling with aryl boron compounds and alkyl 9-BBN reagents (see scheme; 9-BBN=9-borabicyclo[3.3.1]nonane). The reactions proceed with practically useful reactivities and thus complement palladium- and nickel-catalyzed Suzuki-Miyaura coupling reactions of alkyl halides.
- Yang, Chu-Ting,Zhang, Zhen-Qi,Liu, Yu-Chen,Liu, Lei
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supporting information; experimental part
p. 3904 - 3907
(2011/05/15)
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- Itraconazole Side Chain Analogues: Structure-Activity Relationship Studies for Inhibition of Endothelial Cell Proliferation, Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) Glycosylation, and Hedgehog Signaling
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Itraconazole is an antifungal drug that was recently found to possess potent antiangiogenic activity and anti-hedgehog (Hh) pathway activity. To search for analogues of itraconazole with greater potency and to understand the structure-activity relationship in both antiangiogenic and Hh targeting activity, 25 itraconazole side chain analogues were synthesized and assayed for inhibition of endothelial cell proliferation and Gli1 transcription in a medulloblastoma (MB) culture. Through this analysis, we have identified analogues with increased potency for inhibiting endothelial cell proliferation and the Hh pathway, as well as VEGFR2 glycosylation that was recently found to be inhibited by itraconazole. An SAR analysis of these activities revealed that potent activity of the analogues against VEGFR2 glycosylation was generally driven by side chains of at least four carbons in composition with branching at the α or β position. SAR trends for targeting the Hh pathway were divergent from those related to HUVEC proliferation or VEGFR2 glycosylation. These results also suggest that modification of the sec-butyl side chain can lead to enhancement of the biological activity of itraconazole.
- Shi, Wei,Nacev, Benjamin A.,Aftab, Blake T.,Head, Sarah,Rudin, Charles M.,Liu, Jun O.
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supporting information; experimental part
p. 7363 - 7374
(2011/12/04)
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- Amphiphilic organocatalyst for schotten-baumann-type tosylation of alcohols under organic solvent free condition
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A Tosylation of primary alcohol with tosyl chloride was performed effectively with an W-hexadecylimidazole catalyst in water containing K 2CO3 aggregation of the catalyst carrying a hydrophobic methylene chain worked as a substitute for organic solvent.
- Asano, Keisuke,Matsubara, Seijiro
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supporting information; experimental part
p. 1757 - 1759
(2009/09/06)
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- Stereoselective synthesis of bioactive isosteviol derivatives as α-glucosidase inhibitors
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Considerable interest has been attracted in isosteviol and its derivatives because of their large variety of pharmacological activities. In this project, a series of novel compounds containing hydroxyl, hydroxymethyl group and heteroatom-containing frameworks fused with isosteviol structure were synthesized and evaluated as α-glucosidase inhibitors, aimed at clarifying the structure-activity correlation. The results indicated that these isosteviol derivatives were capable of inhibiting in vitro α-glucosidase with moderate to good activities. Among them, indole derivative 15b exhibited the highest activities and thus may be exploitable as a lead compound for the development of potent α-glucosidase inhibitors.
- Wu, Ya,Yang, Jing-Hua,Dai, Gui-Fu,Liu, Cong-Jun,Tian, Guo-Qiang,Ma, Wen-Yan,Tao, Jing-Chao
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experimental part
p. 1464 - 1473
(2009/09/05)
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- PROCESS FOR PRODUCTION OF SULFONIC ACID ESTER
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The present invention provides a method for producing a sulfonate ester efficiently and in high yield. The present invention is an invention of a method for producing a sulfonate ester compound, which comprising reacting: (a) a compound having a sulfo group (-SO3H); and (b) a compound having a group represented by the general formula [1]: ????????-OR1?????[1] [wherein, R1 represents a sulfonyl group represented by the general formula [2]: ????????-SO-R2?????[2] (wherein, R2 represents a halogen atom, a haloalkyl group, an alkoxy group, or an optionally substituted alkyl group or an optionally substituted aryl group) or an acyl group represented by the general formula [3]: (wherein, R3 represents an optionally substituted alkyl group or an optionally substituted aryl group)]; in the presence of an organic base which is capable of forming a salt with said sulfo group.
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Page/Page column 22
(2009/06/27)
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- Chemoselective and scalable preparation of alkyl tosylates under solvent-free conditions
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The improved method for the efficient tosylation of alcohols has been reported using two procedures (A and B). Procedure A: methanol, ethanol, benzyl alcohols, and valuable ethylene glycols can be converted into their corresponding alkyl tosylates in very fast, simple, and efficient grinding method using potassium carbonate as solid base. Other primary and secondary alcohols need to add potassium hydroxide to reaction mixture (procedure B). High selectivity of tosylation was observed for these two procedures. Scale up ability was found in this method even in 100 mmol of substrate. The present method is the example of solid-state tosylation using tosyl chloride, and is a green chemical process due to solvent-free conditions.
- Kazemi, Foad,Massah, Ahmad R.,Javaherian, Mohammad
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p. 5083 - 5087
(2008/02/01)
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- A new preparative method of aryl sulfonate esters by using cyclic organobismuth reagents
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A new method for the preparation of aryl sulfonate esters by using a cyclic pentavalent bismuth is described. Aryl sulfonate esters are formed in good to high yields by treating 10-arylphenothiabismine 5,5-dioxides, m-chloroperoxybenzoicacid (m-CPBA)and various sulfonic acids in dichloromethane.
- Sakurai, Naoto,Mukaiyama, Teruaki
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p. 771 - 790
(2008/09/18)
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- MANUFACTURING METHOD FOR POLYCARBONATE
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A method for manufacturing polycarbonate by melt-polycondensing bisphenol and carbonic acid diester uses as catalyst an alkali metal compound and/or alkaline earth metal compound (a). The catalyst is added to the bisphenol prior to the melt polycondensation, in an effective amount, i.e., the amount of alkali metal compound and/or alkaline earth metal compound (a) that acts effectively as a catalyst, is contained in said bisphenol, and is controlled to have the same catalytic activity as 1×10?8 to 1×10?6 mole of bisphenol disodium salt per mole of pure bisphenol A. The method conducts the reaction efficiently from the initial stage in a stable manner to obtain polycarbonate with good color, good heat stability and color stability during molding and the like.
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- Synthesis of alkyl sulfonates from sulfonic acids or sodium sulfonates using solid-phase bound reagents
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An efficient and selective method for the synthesis of sulfonic esters from sulfonic acids or sodium sulfonates using polymer-bound primary triazenes based upon the T2* linker has been developed. The purities of the esters obtained are usually greater tha
- Vignola, Nicola,Dahmen, Stefan,Enders, Dieter,Br?se, Stefan
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p. 7833 - 7836
(2007/10/03)
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- Montmorillonite clay catalyzed tosylation of alcohols and selective monotosylation of diols with p-toluenesulfonic acid: An enviro-economic route
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An enviro-economic route for tosylation of alcohols and selective monotosylation of diols in good yield directly using p-toluenesulfonic acid together with metal-exchanged montmorillonite instead of p-toluenesulfonyl chloride or p-toluenesulfonic anhydrid
- Choudary, Boyapati M.,Chowdari, Naidu S.,Kantam, Mannepalli L.
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p. 7291 - 7298
(2007/10/03)
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- Ester compounds
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An ester compound represented by the formula: wherein R is a hydrogen atom, a C1-C3 alkyl group unsubstituted or substituted with one or more halogen atoms, an allyl group unsubstituted or substituted with one or more halogen atoms, or a propargyl group unsubstituted or substituted with one or more halogen atoms; and X is a hydrogen atom, a halogen atom, a C1-C3 alkyl group unsubstituted or substituted with one or more halogen atoms, a C2-C3 alkenyl group unsubstituted or substituted with one or more halogen atoms, a C2-C3 alkynyl group unsubstituted or substituted with one or more halogen atoms, a C1-C3 alkoxy group unsubstituted or substituted with one or more halogen atoms, a C1-C3 alkylthio group unsubstituted or substituted with one or more halogen atoms, or a C1-C3 alkoxymethyl group containing a C1-C3 alkoxy group unsubstituted or substituted with one or more halogen atoms, has an excellent pest-controlling effect.
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- Reactivity of methoxide ion in concentrated methanolic solutions of Et4NOCH3 and Et4NCl
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Bimolecular rate constants k were determined for reactions of 4-nitrophenyl 4-toluenesulfonate, diethyl 4-nitrophenyl phosphate, and ethyl 4-nitrophenyl ethylphosphonate with tetraethylammonium methoxide Et4NOCH3 in methanol at 25°C over a wide range of Et4NOCH3 concentrations, where the reagent acts simultaneously as electrolyte, and at [Et4NOCH3] ≤ 0.1 M (reagent) with variation of Et4NCl (electrolyte) concentration. The relation logk = logk0 + b[Et4NX] is fulfilled up to [Et4NX] = 3.5 M, indicating that the electrolyte affects the reaction rate through restructurization of methanol as reaction medium.
- Savelova,Belousova,Simanenko,Popov
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p. 1790 - 1796
(2007/10/03)
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- Preparation of sulfonamides from sodium sulfonates: Ph3P·Br2 and Ph3P·Cl2 as a mild halogenating reagent for sulfonyl bromides and sulfonyl chlorides
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Arene- and alkanesulfonamides were prepared by treatment of the corresponding sodium sulfonates with triphenylphosphine dibromide or dichloride followed by amines in the presence of triethylamine via sulfonyl halides. Reactions of sodium aminosulfonates gave cyclized products. Amidation of p-toluenesulfonic acid with triphenylphosphine dichloride was also examined to give N-benzyl-p-toluenesulfonamide. Methyl p- toluenesulfonate was obtained by esterification of sodium p-toluenesulfonate via p-toluenesulfonyl chloride.
- Kataoka, Tadashi,Iwama, Tetsuo,Setta, Tomofumi,Takagi, Atsuko
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p. 423 - 426
(2007/10/03)
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- Stabilization of benzylic radicals by substituents: An EPR study of para-substituted benzyl radicals
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Accurate determinations have been made for the EPR coupling constants of 15 para-substituted benzyl radicals. These data, along with literature data for other systems have been used to reassess the stabilizing effect of para-substituents on benzylic radicals, and to throw light on the possible destabilizing effects of para F and CF3 substituents.
- Jackson, Richard A.,Sharifi, Mahmood
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p. 775 - 778
(2007/10/03)
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- Bimolecular Nucleophilic Substitution (SN2) Reactions of Neopentyl Arenesulfonates with Anilines and Benzylamines in Methanol
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Bimolecular nucleophilic substitution (SN2) reactions of neopentyl arenesulfonates with anilines and benzylamines in methanol at 55.0 deg C are reported.The tightness of the transition state (TS) is similar to that for other typical SN2 processes at a primary alkyl carbon centre based on the magnitude of the cross-interaction constant ρxz (0.30) between the substituents in the nucleophile (X) and leaving group (Z).The TS variation is in accord with that predicted by the potential energy surface diagram, which in turn is consistent with the positive sign of ρxz; a later TS is obtained with a weaker nucleophile and nucleofuge.Taft's polar substituent constant, ?*, for the trimethylsilyl group is estimated to be -0.48 by using a factor of 1.875 for the fall-off of ?* from the tert-butyl to the neopentyl group and extrapolating from the experimental Taft plot.
- Koh, Han Joong,Lee, Hai Whang,Lee, Ikchoon
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p. 253 - 258
(2007/10/02)
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- Sulfonyl Esters. V. A Preparation of Dichloromethyl Sulfones
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α-Sulfonyl methyl esters have been chlorinated in the presence of base.Chlorination proceeds with accompanying demethoxycarbonylation to furnish dichloromethyl sulfones in good yields.
- Langler, Richard Francis,Steeves, Jennifer Lea
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p. 1641 - 1646
(2007/10/02)
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- Facile esterification of sulfonic acids and carboxylic acids with triethylorthoacetate
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Triethylorthoacetate was found to be surprisingly more effective than triethylorthoformate in the esterification of sulfonic acids and carboxylic acids. Using this reagent, esters of sulfonic and carboxylic acids are prepared in high yields.
- Trujillo, John I.,Gopalan, Aravamudan S.
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p. 7355 - 7358
(2007/10/02)
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- Reactivity of Neopentyl-Like Compounds in the Synthesis of Branched Polyethers
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Two singly branched symmetrical hexaethers have been synthesized, starting from 2-bromomethyl-2-methyl-1,3-dibromopropane, in a surprisingly efficient one-pot nucleophilic substitution reaction.It is proposed that the expected adverse neopentyl effect is compensated by favourable neighbouring-group participation involving a 'bromonium'-like four-membered-ring transition state.The corresponding trichloride also reacted cleanly, although much more slowly, while the tritosylate gave an oxetane derivative.
- Dale, Johannes,Fredriksen, Siw B.
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p. 278 - 282
(2007/10/02)
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- Limitations of the Transition-state Variation Model. Part 3. Solvolyses of Electron-rich Benzenesulphonyl Chlorides
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Rate constants for solvolyses of 4-methoxy-2,6-dimethylbenzenesulphonyl chloride 3 (Z = OMe) and of 4-methyl- and 4-methoxybenzenesulphonyl chlorides 4 (Z = Me and OMe) are reported for aqueous binary mixtures with acetone, ethanol and methanol.Some additional rate constants are reported for aqueous acetonitrile and dioxane mixtures, as well as product selectivities (S) in alcohol-water mixtures.For each binary mixture, rates of solvolyses of 3 (Z = OMe) vs.YCl or Y are approximately bilinear.As water is added to alcohol, S values for solvolyses of 3 (Z = OMe) pass through a maximum and for solvolyses of 4-methoxybenzenesulphonyl chloride 4 (Z = OMe) the position of the maximum shifts to more aqueous media.For solvolyses of 4-methyl-benzenesulphonyl chloride 4 (Z = Me), S values are shifted such that they reach a plateau rather than a maximum, and the rate-rate profiles with YCl are approximately linear rather than bilinear.All of rate-rate profiles show 'dispersion' into separate correlations for the various binary mixtures.These substituent effects follow the same trends as corresponding solvolyses of benzoyl chloride and strengthen recent proposals that solvolyses of 3 (Z = Me) proceed via competing (dual) reaction channels.
- Koo, In Sun,Bentley, William T.,Llewellyn, Gareth,Yang, Kiyull
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p. 1175 - 1179
(2007/10/02)
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- Pyrrolidone compounds for treating cerebral disorders
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New pyrrolidone compounds of the formula: STR1 in which: R is OR", SR" or N (R3 R4) R' is optionally substituted alkyl or aryl, and the carbon in the 5-position of the pyrrolidone ring, which is substituted by CH2 R has the R or S configuration. These new compounds and their physiologically tolerable salts may be used therapeutically especially in the treatment of asthenias, ischaemic syndromes and nervous disorders associated with normal or pathological ageing.
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- Alkynyliodonium Salts as Alkynylating Reagents: Direct Conversion of Alkynylphenyliodonium Tosylates to Dialkyl Alkynylphosphonates with Trialkyl Phosphites
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The treatment of various alkynyl(phenyl)iodonium tosylates 1 (R = t-Bu, s-Bu, i-Pr, cyclopentyl, Ph, and p-MeC6H4; X(-) = OTs(-)) with neat trimethyl phosphite gave the dimethyl alkynylphosphonates 4a and 4d-h in isolated yields ranging from 34 to 90percent.Similar treatment of 1 (R = t-Bu, X(-) = OTs(-)) with neat triethyl and triisopropyl phosphites gave the diethyl and diisopropyl alkynylphosphonates 4b (81percent) and 4c (58percent).The byproducts of these reactions are alkyl tosylates and iodobenzene.The high yields of iodobenzene, determined by GC analysis for the reactions of 1 (R = s-Bu, p-tolyl; X(-) = OTs(-)) with trimethyl phosphite, indicate that the cleavage of the alkynyl(phenyl)iodonium ions with trialkyl phosphites proceeds with high regioselectivity at the alkynyl ligand.
- Lodaya, Jayant S.,Koser, Gerald F.
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p. 1513 - 1516
(2007/10/02)
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- An Electrochemical Variant in the Syntheses of Exaltone and Muscone: Anodic Fragmentation of α,β-Unsaturated Tosylhydrazones
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Ring enlargement of bicyclopentadec-1(12)-en-13-one p-toluenesulfonylhydrazone into cyclopentadec-4-yn-1-one was accomplished under mild and controlled anodic oxidation conditions.The mechanism of this fragmentation is reconsidered.
- Limacher, Liviana L.,Delay, Francois D.,Bedert, Nicole,Tissot, Paul
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p. 1383 - 1389
(2007/10/02)
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- Pathways in the Reactions of Nitronate Ions with Sulphonyl Halides
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Primary and tertiary nitronate ions and sulphonyl bromides and iodides rapidly equilibrate with the nitrohalides and sulphinate ion.Products are determined by solvent and by the occurence of cross-equilibrum reactions, some of which have single-electron-transfer mechanism.The reaction of arene-sulphinate and thiolate ions with 1,2-dibromo-2-nitro-1-phenylethane gave E-β-nitrostyrene by Z-philic elimination in both cases, but the more basic thiolate ion also gave, by protophilic elimination, 2-bromo-2-nitro-1-phenylethene.
- Pigou, Paul E.,Stirling, Charles J. M.
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p. 725 - 730
(2007/10/02)
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- Sulphonic Acid-induced Fragmentation of Dialkyl Acylphosphonates, Formation of Alkyl Carboxylates and Alkyl Sulphonates
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Heating of dialkyl acylphosphonates with sulphonic acids under anhydrous conditions leads to the formation of alkyl sulphonates and alkyl carboxylates. 31P N.m.r. spectroscopy revealed that the reaction of equimolar amounts of dimethyl benzoylphosphonate (1) and toluene-p-sulphonic acid at room temperature gives dimethyl phosphonate (6) in 50percent yield.It is proposed that the by-product of this reaction, benzoic toluene-p-sulphonic anhydride (8), reacts with the excess of toluene-p-sulphonic acid, to yield toluene-p-sulphonic anhydride (9) and benzoic acid.Heating of these two compounds with dimethyl phosphonate was shown to yield methyl toluene-p-sulphonate and methyl benzoate, respectively.A postulated by-product of these reactions is phosphenous acid (HPO2).Quantum mechanical calculations by the MNDO/H method carried out on dimethyl benzoylphosphonate and its protonation products show that the preferred site of protonation of dimethyl benzoylphosphonate is the P=O oxygen, and that protonation at this site is followed by C-P bond breaking, with zero energy of activation, leading to dimethyl phosphite and benzoylium cation.
- Breuer, Eli,Karaman, Rafik,Goldblum, Amiram,Leader, Haim
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p. 2029 - 2034
(2007/10/02)
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- DIRECT FUNCTIONALIZATION OF SULFIDES WITH HYPERVALENT IODINE REAGENTS: METHOXYSULFONIUM AND AMIDOSULFONIUM TOSYLATES
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benzene (1) and N-phenyliodonio carboxamide tosylates (3) react with sulfides in dichloromethane to give methoxysulfonium and amidosulfonium tosylates.
- Koser, Gerald F.,Kokil, Pandurang B.,Shah, Mayur
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p. 5431 - 5434
(2007/10/02)
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- REACTION OF PHOSPHORUS OXYACID ESTERS WITH p-TOLUENESULFONIC ACID
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The reaction of primary alkyl esters of phosphorus oxyacids with p-toluenesulfonic acid (TsOH) in refluxing solvents gave the corresponding p-toluenesulfonates (TsOR).We found that the secondary alkyl esters reacted with TsOH at lower temperature (r.t.-40 deg C) to afford TsORs in good yields.It is suggested that sulfonic acids may be useful for the selective dealkylation of mixed esters.Keywords-p-toluenesulfonic acid; p-toluenesulfonate; trialkyl phosphate; trialkyl phosphite; dialkyl phenylphosphonate; transesterification; dealkylation; solvolysis.
- Nitta, Yoshihiro,Arakawa, Yasushi,Ueyama, Naoto
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p. 2710 - 2718
(2007/10/02)
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