- Convergent Synthesis of Immune Inhibitor IMMH002
-
A convergent synthesis of IMMH002 in 36% overall yield starting from bromobenzene is described with a key Suzuki-Miyaura cross-coupling reaction used to provide a crucial intermediate. The route does not require column chromatography and solves the most intractable quality problem caused by a homologue by-product in the original linear synthesis. Furthermore, reducing the use of Lewis acid mediated reactions improves the environmental impact of the synthesis and reduces overall waste. The new route described herein is more efficient, convenient, reliable, and economically more viable when compared to the previously reported linear route.
- Chen, Si,Shi, Zeyu,Xiao, Qiong,Yin, Dali
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p. 1174 - 1180
(2020/10/30)
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- A practical synthesis of α-bromo/iodo/chloroketones from olefins under visible-light irradiation conditions
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A practical synthesis of α-bromo/iodo/chloroketones from olefins under visible-light irradiation conditions has been developed. In the presence of PhI(OAc)2 as promoter and under ambient conditions, the reactions of styrenes and triiodomethane undergo the transformation smoothly to deliver the corresponding α-iodoketones without additional photocatalyst in good yields under sunlight irradiation. Meanwhile, the reactions of styrenes with tribromomethane and trichloromethane generate the desired α-bromoketones and α-chloroketones in high yields by using Ru(bpy)3Cl2 as a photocatalyst under blue LED (450–455 nm) irradiation.
- Wang, Zhihui,Wang, Lei,Wang, Zhiming,Li, Pinhua,Zhang, Yicheng
-
supporting information
p. 429 - 432
(2020/02/29)
-
- Preparation method of pusaimode (Chinese name)
-
The invention discloses a preparation method of pusaimode. Bromo-benzene is used as an initial raw material to prepare pusaimode by adopting a convergent synthesis route. The yield of the preparationmethod is high, the cost is low, the amount of generated waste water, waste gas, and waste solids is low, the operation is convenient, and the application value is high.
- -
-
Paragraph 0051-0054
(2020/05/29)
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- Preparation method of aituomode
-
The invention discloses a preparation method of aituomode. Bromo-benzene is used as an initial raw material to prepare aituomode by adopting a convergent synthesis route. The yield of the preparationmethod is high, the cost is low, the amount of generated waste water, waste gas, and waste solids is low, the operation is convenient, and the application value is high.
- -
-
Paragraph 0051-0054
(2020/05/29)
-
- Preparation method of aituomode
-
The invention discloses a preparation method of aituomode. Bromo-benzene and benzene are used as initial raw materials to prepare aituomode by adopting a convergent synthesis route. The yield of the preparation method is high, the cost is low, the amount of generated waste water, waste gas, and waste solids is low, the operation is convenient, and the application value is high.
- -
-
Paragraph 0043-0046
(2020/05/29)
-
- Preparation method of pusaimode (Chinese name)
-
The invention discloses a preparation method of pusaimode. Bromo-benzene and benzene are used as initial raw materials to prepare pusaimode by adopting a convergent synthesis route. The yield of the preparation method is high, the cost is low, the amount of generated waste water, waste gas, and waste solids is low, the operation is convenient, and the application value is high.
- -
-
Paragraph 0042; 0044; 0045
(2020/05/29)
-
- Design and synthesis of analogues of the sphingosine-1-phosphate receptor 1 agonist IMMH001 with improved phosphorylation rate in human blood
-
IMMH001, which is a prodrug for sphingosine-1-phosphate receptor 1 (S1P1) agonist, is converted to the active form, its monophosphate ester (S)-IMMH001-P, by sphingosine kinase 1 (SphK1) and sphingosine kinase 2 (SphK2) in vivo. In this study, we designed head-piece-modified analogues of IMMH001 based on structural information and prepared them with an efficient modular synthetic strategy. The analogues showed higher phosphorylation rates in human blood than the parent compound. These results indicated that the pro-R hydroxymethyl in the head-piece-moiety of IMMH001 prevents the pro-S hydroxymethyl from being phosphorylated by the kinase and ATP. The analogues may have better therapeutic potential.
- Xiao, Qiong,Hu, Minwan,Chen, Si,Shi, Zeyu,Hu, Jinping,Xie, Ping,Yin, Dali
-
-
- Facile Synthesis of α-Haloketones by Aerobic Oxidation of Olefins Using KX as Nonhazardous Halogen Source
-
An operationally simple and safe synthesis of α-haloketones using KBr and KCl as nonhazardous halogen sources is reported. It involves an iron-catalysed reaction of alkenes with KBr/KCl using O2 as terminal oxidant under the irradiation of visible-light. This strategy avoids the risks associated with handling halo-contained electrophiles (Cl2, Br2, NCS, NBS). The process is tolerant to several functional groups, and extended to a range of substituted styrenes in up to 89% yield. A radical reaction pathway is proposed based on control experiments and spectroscopy studies.
- Luo, Zhibin,Meng, Yunge,Gong, Xinchi,Wu, Jie,Zhang, Yulan,Ye, Long-Wu,Zhu, Chunyin
-
supporting information
p. 173 - 177
(2020/01/02)
-
- Iodine-DMSO-promoted divergent reactivities of arylacetylenes
-
An unprecedented set of efficient, economical, atom-economic and exceedingly selective I2-DMSO-promoted methods is described for the generation of different structures. The reaction represents the first of its kind, involving the use of different iodine concentrations, temperatures, acids and salt to adjust the selectivity for the synthesis of different alkenes, α-functionalized ketones and α-ketomethylthioesters.
- Rather, Suhail A.,Kumar, Atul,Ahmed, Qazi Naveed
-
supporting information
p. 4511 - 4514
(2019/04/26)
-
- The Mn-catalyzed paired electrochemical facile oxychlorination of styrenes: Via the oxygen reduction reaction
-
Reported herein is the electrochemical engendering of chlorine radicals by a manganese catalyst with a controllable pattern, and inexpensive MgCl2 as the chlorine source. In combination with the oxygen reduction reaction, chloroacetophenones were synthesized with abundant styrene as the feedstock in good to excellent yields.
- Tian, Siyu,Jia, Xiaofei,Wang, Ling,Li, Baoying,Liu, Siyuan,Ma, Li,Gao, Wei,Wei, Yingqin,Chen, Jianbin
-
supporting information
p. 12104 - 12107
(2019/10/14)
-
- CV-driven Optimization: Cobalt-Catalyzed Electrochemical Expedient Oxychlorination of Alkenes via ORR
-
Instead of screening reaction conditions by yield-based chemical trial-and-error, potential-based cyclic voltammetry was alternatively employed for optimization of electrochemical oxychlorination of alkenes. With this unconventional screening method, the catalyst system including catalysts, molar ratio of chloride sources and solvents were identified in a rational, time- and energy-efficient manner. The optimal catalytic system in combination with oxygen reduction reaction enabled broad substrate scopes for the desired transformation by taking advantages of persistent radical effect. UV-vis and CV titration experiments confirmed the in-situ formed catalytic species [CoCl5]. Moreover, cyclic voltammetry was applied to obtain mechanistic insights in our reaction system. (Figure presented.).
- Tian, Siyu,Lv, Shide,Jia, Xiaofei,Ma, Li,Li, Baoying,Zhang, Guofeng,Gao, Wei,Wei, Yingqin,Chen, Jianbin
-
supporting information
p. 5626 - 5633
(2019/11/22)
-
- Iridium-Catalyzed Asymmetric Hydrogenation of Halogenated Ketones for the Efficient Construction of Chiral Halohydrins
-
Iridium-catalyzed asymmetric hydrogenation of prochiral halogenated ketones was successfully developed to prepare various chiral halohydrins with high reactivities and excellent enantioselectivities under basic reaction condition (up to >99% conversion, 99% yield, >99% ee). Moreover, gram-scale experiment was performed well in the presence of just 0.005 mol% (S/C=20 000) Ir/f-amphox catalyst with 99% yield and >99% ee. (Figure presented.).
- Yin, Congcong,Wu, Weilong,Hu, Yang,Tan, Xuefeng,You, Cai,Liu, Yuanhua,Chen, Ziyi,Dong, Xiu-Qin,Zhang, Xumu
-
supporting information
p. 2119 - 2124
(2018/04/30)
-
- Cascade Trisulfur Radical Anion (S3?-) Addition/Electron Detosylation Process for the Synthesis of 1,2,3-Thiadiazoles and Isothiazoles
-
Trisulfur radical anion (S3?-) mediated reactions with in situ formed azoalkenes and α,β-usaturated N-sulfonylimines for the construction of 1,2,3-thiadiazoles and isothiazoles has been developed. S3?- is in situ generated from potassium sulfide in DMF. These two approaches provide a new, safe, and simple way to construct 4-subsituted 1,2,3-thiadiazoles, 5-subsituted 1,2,3-thiadiazoles, and isothiazole in good yields. The reactions include the formation of the new C-S and N-S bonds via S3?- addition and electron detosylation under mild conditions.
- Liu, Bei-Bei,Bai, Hui-Wen,Liu, Huan,Wang, Shun-Yi,Ji, Shun-Jun
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p. 10281 - 10288
(2018/07/25)
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- Mild Homologation of Esters through Continuous Flow Chloroacetate Claisen Reactions
-
The selective chloromethylenation of functionalized esters using chloroacetic acid (CA) and LiHMDS (HMDS=hexamethyldisilazide) in a continuous-flow setup is reported. This Claisen homologation is for the first time extended to bis-chloromethylenation using dichloroacetic acid (DCA), thus giving access to under-explored α,α′-bis-chloroketones. The use of flow conditions enables efficient generation and reaction of the unstable chloroacetate dianion intermediates, leading to unprecedented mild and scalable reaction conditions at an economical reagent stoichiometry (?10 °C, 1 min, 1.0–2.4 equiv dianion). The clean reaction profiles allow subsequent use of the unpurified crude products, which is demonstrated in the synthesis of various heterocycles of broad interest. Furthermore, we report a novel, catalyst-free substitution of the obtained monochloro ketone products with (hetero)aryl zinc enolates to give valuable 1,4-diketones.
- Ganiek, Maximilian A.,Ivanova, Maria V.,Martin, Benjamin,Knochel, Paul
-
supporting information
p. 17249 - 17253
(2018/12/05)
-
- Systematic Synthesis of Diphenyl-Substituted Carotenoids as Molecular Wires
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A general method for the construction of diphenyl-substituted carotenoids has been developed through the stereoselective synthesis of dienyl sulfones with a phenyl substituent. Systematic synthetic pathways to the dienyl sulfones were delineated starting from readily available acetophenones with para-substituent X of various electronic natures, which provided the carotenoids with diverse physicochemical characteristics. The sulfone olefination method together with the Ramberg–B?cklund reaction produced a 9,9′-cis-10,10′-diphenylcarotene and all-trans-9,9′-diphenylcarotenes. Conductance measurements of the all-trans carotenoids by the scanning tunnelling microscopy break-junction method revealed a positional effect of the phenyl groups as well as a polar effect of the phenyl substituent X according to the electronic nature.
- Lim, Boram,Oh, Eun-Taek,Im, JongOne,Lee, Kyu Sang,Jung, Hyunuk,Kim, Minsoo,Kim, Dahye,Oh, Jung Taek,Bae, Sung-Hee,Chung, Wook-Jin,Ahn, Kwang-Hyun,Koo, Sangho
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p. 6390 - 6400
(2017/12/01)
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- A Simple and Efficient Method for the Preparation of α-Halogenated Ketones Using Iron(III) Chloride and Iron(III) Bromide as Halogen Sources with Phenyliodonium Diacetate as Oxidant
-
α-Halogenated ketones are both unique structure moieties existing in biologically natural products and valuable synthetic intermediates for the preparation of functional molecules. An efficient and scalable method for the preparation of α-halogenated ketone using iron (III) chloride and iron (III) bromide as halogen sources with phenyliodonium diacetate as oxidant has been developed, featuring mild reaction conditions, environmentally friendly reagents, and wide substrate scope. Notably, the three-step synthesis of drug prasugrel was achieved using this developed method as a key step with 30% yield on gram-scale. Additionally, the reaction mechanism involving chloride cation was proposed based on some preliminary control experiments. (Figure presented.).
- Tang, Shi-Zhong,Zhao, Wenshuang,Chen, Tao,Liu, Yang,Zhang, Xiao-Ming,Zhang, Fu-Min
-
supporting information
p. 4177 - 4183
(2017/12/18)
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- Mechanochemical solid-state synthesis of 2-aminothiazoles, quinoxalines and benzoylbenzofurans from ketones by one-pot sequential acid- and base-mediated reactions
-
α-Chloroketones-obtained by the atom-economical chlorination of ketones with trichloroisocyanuric acid (TCCA) in the presence of p-TSA under ball-milling conditions-were set up for a sequential base-mediated condensation reaction with thiourea/thiosemicarbazides, o-phenylenediamine and salicylaldehyde to afford 2-aminothiazoles, 2-hydrazinylthiazoles, quinoxalines and benzoylbenzofurans, respectively, in respectable yields. The viability of one-pot sequential acid- and base-mediated reactions in the solid state under ball-milling conditions is thus demonstrated.
- Nagarajaiah, Honnappa,Mishra, Abhaya Kumar,Moorthy, Jarugu Narasimha
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p. 4129 - 4135
(2016/06/14)
-
- Laboratory-Scale Membrane Reactor for the Generation of Anhydrous Diazomethane
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A configurationally simple and robust semibatch apparatus for the in situ on-demand generation of anhydrous solutions of diazomethane (CH2N2) avoiding distillation methods is presented. Diazomethane is produced by base-mediated decomposition of commercially available Diazald within a semipermeable Teflon AF-2400 tubing and subsequently selectively separated from the tubing into a solvent- and substrate-filled flask (tube-in-flask reactor). Reactions with CH2N2 can therefore be performed directly in the flask without dangerous and labor-intensive purification operations or exposure of the operator to CH2N2. The reactor has been employed for the methylation of carboxylic acids, the synthesis of α-chloro ketones and pyrazoles, and palladium-catalyzed cyclopropanation reactions on laboratory scale. The implementation of in-line FTIR technology allowed monitoring of the CH2N2 generation and its consumption. In addition, larger scales (1.8 g diazomethane per hour) could be obtained via parallelization (numbering up) by simply wrapping several membrane tubings into the flask.
- Dallinger, Doris,Pinho, Vagner D.,Gutmann, Bernhard,Kappe, C. Oliver
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p. 5814 - 5823
(2016/07/26)
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- A novel β-(oxy)alkyl radical during copper(I)-mediated stereoselective synthesis of (Z)-ene-1,4-diones in a reaction of 2,2,2-trichloro-1-phenylethanone
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A novel β-(oxy)alkyl radical derived from trichloro methyl compound containing neither a suitably located C-C multiple bond nor a leaving group or a H-atom at the β-position of the radical in a reaction of 2,2,2-trichloro-1-phenyl-ethanone with 2 mol equiv each of CuCl and bpy in refluxing DCE under a N2 atm underwent intramolecular heterolysis (just like formation of intact radical cation-anion pair) during stereoselective radical dimerization to Z-ene-1,4-dione along with small amount of reductive dechlorination product. The stereochemistry was established by X-ray diffraction spectroscopy of various solid crystalline products.
- Ram, Ram N.,Tittal, Ram K.
-
supporting information
p. 2437 - 2440
(2016/05/19)
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- First Catalyzed Hydration of Haloalkynes by a Recyclable Catalytic System
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The hydration of haloalkynes to give α-halomethyl ketones was achieved based on a combination of a Cu(OAc)2 catalyst and a TFA (trifluoroacetic acid) promoter. This is the first synthesis of chloro/bromo/iodo methyl ketones through a hydration reaction catalyzed by a recyclable catalytic system. The catalytic system has a wide substrate scope and excellent chemoselectivity, and the procedure can also be scaled up.
- Zou, Huaxu,He, Weibao,Dong, Qizhi,Wang, Ruijia,Yi, Niannian,Jiang, Jun,Pen, Dongming,He, Weimin
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p. 116 - 121
(2016/01/26)
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- Highly Efficient Synthesis of α-Halomethylketones via Ce(SO4)2/Acid Co-Catalyzed Hydration of Alkynes
-
A general atom-economical approach for the synthesis of α-halomethyl ketones is demonstrated through Ce(SO4)2/acid co-catalyzed hydration of a wide range of haloalkynes. The reactions are conducted under convenient conditions and provide products with excellent regioselectivity in good to excellent yields, with broad substrate scope. This protocol is an alternative to conventional α-halogenation of ketones.
- Zou, Huaxu,Jiang, Jun,Yi, Niannian,Fu, Wenqiang,Deng, Wei,Xiang, Jiannan
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supporting information
p. 1251 - 1254
(2016/12/27)
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- High-yielding aqueous synthesis of chloroacetophenones and aroyl chlorohydrins
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The use of large amounts of volatile organic solvents in industrial chemical processes contributes to widespread environmental pollution. To help solve this problem, water and a phase transfer catalyst were used to replace organic solvents in the transformations of bromoacetophenones into chloroacetophenones and aroyl epoxides into aroyl chlorohydrins. The reactions were promoted by sulfonyl chlorides and gave quantitative or close to quantitative yields. Notably, chromatographic purification, which is laborious and consumes large amounts of organic solvents, was not needed. These two processes have opened a green and cost-effective channel to prepare the chemical intermediates chloroacetophenones and aroyl chlorohydrins. The reaction mechanisms are discussed based on control experiments.
- Zhang, Xixi,Liu, Lei,Li, Chunbao
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p. 25339 - 25345
(2016/03/22)
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- Design, synthesis and docking-based 3D-QSAR study of novel 2-substituted 2-aminopropane-1,3-diols as potent and selective agonists of sphingosine-1-phosphate 1 (S1P1) receptor
-
Spingosine-1-phosphate receptor 1 (S1P1) has been actively pursued as an important therapeutic target in immune regulation. A series of 2-substituted 2-aminopropane-1,3-diols were designed and synthesized as selective S1P1 agonists. Most of the compounds with a biphenyl ether scaffold showed moderate to excellent S1P1/S1P3 selectivity. Compound 40c is identified as a potent S1P1 agonist with 350-fold S1P1/S1P3 selectivity. 39c, the alcohol form of 40c exerted good lymphopenia activity in vivo but with weak influence on heart rate. To investigate the SARs of 2-substituted 2-aminopropane-1,3-diols in more details, COMFA (q2 = 0.547, r2 = 0.986) and COMSIA (q 2 = 0.544, r2 = 0.943) models were established based on molecular docking alignment, which were validated with high reliability in predicting activities of agonists. The 3D-QSAR models will be helpful in the design of novel, potent and selective S1P1 agonists. The Royal Society of Chemistry.
- Tian, Yulin,Jin, Jing,Wang, Xiaojian,Han, Weijuan,Li, Gang,Zhou, Wanqi,Xiao, Qiong,Qi, Jianguo,Chen, Xiaoguang,Yin, Dali
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supporting information
p. 1267 - 1274
(2013/09/12)
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- Target-oriented synthesis: Miscellaneous synthetic routes to access 1,4-enediones through the coupling of 1,3-dicarbonyl compounds with multiform substrates
-
Target-oriented synthetic protocol was presented for the synthesis of 1,4-enediones. The approach can efficiently construct 1,4-enediones through different reaction pathways from multiform substrates α-halo aromatic ketones, 2-hydroxy-aromatic ketones and methyl carbinols. In this reaction, CuI was found to be the most efficient catalyst. Multiform substrates were also found to perform well to afford the products in a one-pot fashion.
- Zhu, Yan-Ping,Cai, Qun,Gao, Qing-He,Jia, Feng-Cheng,Liu, Mei-Cai,Gao, Meng,Wu, An-Xin
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supporting information
p. 6392 - 6398
(2013/07/25)
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- A simple and convenient method for direct α-chlorination of ketones with ammonium chloride and Oxone
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When ketones were treated with ammonium chloride and Oxone in MeOH at room temperature, a direct α-chlorination of ketones was occurred and a series of the corresponding α-chloroketones were obtained in moderate to good yields after 24 h. In this reaction, ammonium chloride was used as the source of chlorine and Oxone was used as an oxidant. This method was simple, convenient and providing a novel procedure for preparation of α-chloroketones.
- Zhou, Zhong Shi,Li, Li,He, Xue Han
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p. 1213 - 1216,4
(2020/09/16)
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- Mild and efficient α-chlorination of carbonyl compounds using ammonium chloride and oxone (2KHSO5·KHSO4· K2SO4)
-
A simple protocol for the α-monochlorination of ketones and 1,3-dicarbonyl compounds utilizing NH4Cl as a source of chlorine and Oxone as an oxidant in methanol without catalyst is presented. The reaction proceeds at ambient temperature in yields ranging from moderate to excellent.
- Swamy, Peraka,Kumar, MacHarla Arun,Reddy, Marri Mahender,Narender, Nama
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supporting information; experimental part
p. 432 - 434
(2012/06/01)
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- New, efficient synthesis of α-chloroketones using SiCl 4/urea-hydrogen peroxide or SiCl4/iodosylbenzene reagent systems
-
Alkyl aryl ketones on treatment with SiCl4/urea-hydrogen peroxide (UHP) or SiCl4/iodosylbenzne reagent systems afforded -chloroketones in excllent yields, while ketones with higher enol content provide exclusively,-dichloroketones under exceedingly mild conditions. The reaction proceeds via the initial formation of silyl enol ethers. A polarized chlorine intermediate that resulted from the coordination of SiCl4 with the in situ formed trichlorosilyl hypochlorite Cl3SiOCl is thought to be the active chlorinating agent.
- El-Ahl, Abdel Aziz S.,Elbeheery, Akram H.,Amer, Fathy A.
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experimental part
p. 1508 - 1513
(2011/06/17)
-
- Microwave assisted fluorination: an improved method for side chain fluorination of substituted 1-arylethanones
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A two-step, one-pot microwave (MW) assisted fluorination of 1-arylethanones to their corresponding 1-aryl-2-fluoroethanones has been developed. The first step utilises Selectfluor as a fluorinating agent in methanol forming 1-aryl-2-fluoroethanones and their corresponding dimethyl acetals. In the second step, water is added and Selectfluor acts as a Lewis acid in the hydrolytic cleavage of the dimethyl acetals. Compared to the thermal synthesis, the MW assisted method leads to a reduction in reaction time both in the fluorination and for the dimethyl acetal cleavage. Moreover, the one-pot procedure reduces reagent and solvent consumption. The method is best suited for the preparation of 1-aryl-2-fluoroethanones containing substituents that deactivates electrophilic aromatic substitution, however highly electron deficient ketones such as 1-(3,5-dinitrophenyl)ethanone reacts more slowly. Reactions using electron rich aromatic ketones had a low regioselectivity, and also produced fluoroaromatic products.
- Krane Thvedt, Thor H?kon,Fuglseth, Erik,Sundby, Eirik,Hoff, B?rd Helge
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scheme or table
p. 9550 - 9556
(2010/02/27)
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- Simple and efficient methods for selective preparation of α-mono or α,α-dichloro ketones and β-ketoesters by using DCDMH
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New processes that can selectively prepare α-mono or α,α-dichloro ketones and β-ketoesters using 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) are reported. Using silica gel as the catalyst and methanol as the solvent and heating for 1 h under reflux, α-monochlorinated products were selectively obtained in 86-98% yield. However using a deep eutectic solvent (choline chloride: p-TsOH = 1:1) as the solvent and stirring for 45 min at room temperature, α,α- dichlorinated products were selectively obtained in 86-95% yield.
- Chen, Zizhan,Zhou, Bin,Cai, Huihua,Zhu, Wei,Zou, Xinzhuo
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experimental part
p. 275 - 278
(2010/04/22)
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- THIAZOLE DERIVATIVES AS ANDROGEN RECEPTOR MODULATOR COMPOUNDS
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Provided herein are compounds that bind to androgen receptors and/or modulate activity of androgen receptors and/or modulate the amount of androgen receptors and/or reduce the number of androgen receptors in a cell and/or degrade androgen receptors in a cell; and to methods for making and using such compounds. Also provided are compositions containing such compounds and methods for making and using such compositions.
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Page/Page column 81; 118
(2008/12/04)
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- Copper(I)-promoted synthesis of chloromethyl ketones from trichloromethyl carbinols
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(Chemical Equation Presented) Reaction of several trichloromethyl carbinols with 2 equiv of CuCl/bpy in refluxing DCE for 3 h afforded chloromethyl ketones in excellent yield by 1,2-H shift in the copper-chlorocarbenoid intermediate.
- Ram, Ram N.,Manoj
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p. 5633 - 5635
(2008/12/21)
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- Microwave-assisted synthesis of α-hydroxy ketone and α-diketone and pyrazine derivatives from α-halo and α,α′-dibromo ketone
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A novel reaction of α-halo ketone (α-bromo and α-chloro ketone) with irradiation under microwave gave the corresponding α-hydroxyketone and pyrazine derivative in good yields. In the case of α,α′-dibromo ketone, α-diketone was obtained. This reaction affords a new, clean and convenient synthetic method for α-hydroxyketone, α-diketone, α-chloro ketone and pyrazine derivative.
- Utsukihara, Takamitsu,Nakamura, Hiroaki,Watanabe, Masashige,Akira Horiuchi
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p. 9359 - 9364
(2008/01/27)
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- α-chlorination of acetophenones using 1,3-dichloro-5,5- dimethylhydantoin
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A novel method for the synthesis of α-chloroacetophenones using 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) and p-toluenesulfonic acid in methanol at 30-35°C is described. Substituted acetophenones at the para position or meta position of aromatic ring give α-chloroacetophenones in high yield. However, reaction of o-nitroacetophenone does not take place under the same condition. Copyright Taylor & Francis LLC.
- Xu, Zijin,Zhang, Deyan,Zou, Xinzhuo
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p. 255 - 258
(2007/10/03)
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- Efficient α-chlorination of aryl ketones using aluminum chloride/urea-hydrogen peroxide in ionic liquid
-
Effective α-chlorination reactions of aryl ketones into the corresponding α-chloroketones have been accomplished with aluminum chloride hexahydrate and urea-hydrogen peroxide in [bmim]BF4 ionic liquid. Copyright Taylor & Francis Group, LLC.
- Jong, Chan Lee,Hyun, Jung Park
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p. 777 - 780
(2007/10/03)
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- Efficient microwave induced direct α-halogenation of carbonyl compounds
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A novel and direct method for the synthesis of α-halocarbonyl compounds using sequential treatment of carbonyl compounds with [hydroxy(tosyloxy)iodo]benzene followed by magnesium halides under solvent-free microwave irradiation conditions is described.
- Lee, Jong Chan,Park, Jin Young,Yoon, So Young,Bae, Yong Hun,Lee, Seung Jun
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p. 191 - 193
(2007/10/03)
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- Chemoenzymatic synthesis of enantiomerically pure terminal 1,2-diols
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A new practical method for the enzymatic synthesis of 1,2-diols has been developed by employing a lipase catalyzed one-pot transesterification protocol. A series of substituted α-acetoxyphenylethanones 3a-g have been reduced to the corresponding alcohols under mild conditions employing sodium borohydride and moist neutral alumina, and further subjected for lipase catalyzed irreversible transesterification in the same pot to give mono- and diacetate diols (R)-4 and (S)-5, which on hydrolysis afforded terminal 1,2-diols, (R)- and (S)-6 in high enantiomeric excess.
- Kamal, Ahmed,Sandbhor, Mahendra,Ahmed, Kaleem,Adil,Shaik, Ahmad Ali
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p. 3861 - 3866
(2007/10/03)
-
- Process for the preparation of tricyclic amino alcohol derivatives
-
A process for the preparation of tricyclic amino alcohol derivatives including 2-[N-[2-(9H-carbazol-2-yloxy)ethyl]]amino-1-[(3-methylsulfonylamino)phenyl]ethanol useful in the treatment of diabetes, obesity, hyperlipidemia and so on; and intermediates as represented by formula (5) or (6) or the like useful in the preparation, wherein R11 is hydrogen or the like; and *1 represents an asymmetric carbon atom. 2-Halo-1-(3-nitrophenyl)ethanone derivatives and 1-(3-nitrophenyl)oxirane derivatives, which are intermediates for the preparation of tricyclic amino alcohol derivatives, are easy of purification, and particularly optically active 1-(3-nitrophenyl)oxirane derivatives are effective in enhancing the optical purities of the final products.
- -
-
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- α-(4-Nitro Phenoxy) chalcones as synthons for cis-(±)-1,5- benzothiazepines
-
α-(4-Nitro Phenoxy) chalcones, V have been utilized as intermediate for the synthesis of some new cis- (±)-2-aryl-3-(4-nitro phenoxy)-4-phenyl-1,5- benzothiazepine VI by cycloconden-sation of 2-amino thiophenol in the presence of mild base.
- Rao,Arun Kumar Gupta,Gupta
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p. 2763 - 2768
(2007/10/03)
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- A Convenient Halogenation Procedure for the Preparation of α-Halocarbonyl Compounds
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Except for substituted acetophenones (p-Y-C6H4COCH3, Y=H, Br, CH3O), simple ketones, α-ketoesters and 1,3-diketones reacted smoothly with a preformed homogeneous mixture of hydrochloric acid and potassium permanganate in acetonitrile to give moderate to good yields of the corresponding α-chlorocarbonyl compounds.Mixtures of α-chloro- and α,α-dichlorocarbonyl compounds were obtained for substituted acetophenones.Brominations proceeded similarly with higher yields when the hydrochloric acid was replaced with hydrobromic acid. - Key words: α-chlorocarbonyl compounds; α-bromocarbonyl compounds; potassium permanganate; chlorination; bromination.
- Cheng, Sheng-Fan,Lin, Ching-Shan,Liu, Lilian Kao
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p. 309 - 312
(2007/10/03)
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- One-Pot Synthesis of α-Chloro Ketones from Secondary Alcohols Using N,N-Dichloro-p-toluenesulfonamide
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Various alkyl aryl secondary alcohols reacted with N,N-dichloro-p-toluenesulfonamide (N,N-dichloroamine-T) in CH3CN at 35 deg C to give the corresponding α-chloro ketones in excellent yields under mild and neutral conditions.
- Kim, Yong Hae,Lee, In Sang,Lim, Sang Chul
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p. 1125 - 1128
(2007/10/02)
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- α-Chlorination of Aromatic Acetyl Derivatives with Benzyltrimethylammonium Dichloroiodate
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Reaction of aromatic acetyl derivatives with benzyltrimethylammonium dichloroiodate in refluxing dichloroethane/methanol for several hours gave α-chloroacetyl derivatives in good yields.
- Kajigaeshi, Shoji,Kakinami, Takaaki,Moriwaki, Masayuki,Fujisaki, Shizuo,Maeno, Kimihiro,Okamoto, Tsuyoshi
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p. 545 - 546
(2007/10/02)
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- Carbon-13 NMR Spectra of Some 4-Substituted Phenacyl Chlorides and Iodides
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The 13C NMR signals for some 4-substituted phenacyl chlorides and iodides were assigned.The carbonyl carbons exhibit upfield shifts compared with those of the corresponding 4-substituted acethophenones; in the chlorinated derivatives a downfield shift is observed for the α-methylene carbons, while a reverse effect occurs in the iodinated compounds.The chemical shifts of the aromatic ring carbons are in close agreement with those calculated using substituent chemical shifts.KEY WORDS 13C NMR 4-substituted pheacyl chlorides and iodides
- Olivato, Paulo Roberto,Guerrero, Sandra Alvarez,Rittner, Roberto
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p. 179 - 180
(2007/10/02)
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- Kinetics of Oxidation of Ketones by Trichloroisocyanuric Acid in Acid Medium: Anomalous Behaviour of Alkoxyacetophenones
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Kinetics of oxidation of aliphatic, aryl aliphatic and cyclic ketones by trichloroisocyanuric acid has been studied in aqueous acetic acid medium in the presence of HClO4.The reaction is acid-catalysed exhibiting first order dependence each in and and zero order dependence in .This supports the acid catalyzed enolisation of ketone as the rate-determining step and reaction between enol and oxidant as the fast step.Alkoxyacetophenones exhibit an anomalous behaviour in that there is first order dependence on the halogenating agent.This has been attributed to the fact that in the case of alkoxyacetophenones the rates of halogenation may be less than the rates of enolisation.The decrease in dielectric constant of the medium slightly enhances the rate of reaction.The ρ? relationship in the case of acetophenones is linear with ρ as -0.2 indicating the simultaneous operation of equilibrium protonation of ketone and deprotonation of conjugate acid.Arrhenius activation parameters have been computed.A plausible mechanism consistent with the experimental results is postulated.
- Radhakrishnamurti, P. S.,Rath, Nabeen Kumar
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p. 300 - 303
(2007/10/02)
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- REACTION DE L'ACIDE PERCHLORIQUE SUR LES PHENYLACETYLENES SUBSTITUES. MISE EN EVIDENCE D'UN MECANISME IONIQUE ET RADICALAIRE
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We have studied the reaction of perchloric acid in acetic acid medium on some substituted phenylacetylenes.The ionic and radicalar mechanism is in agreement with the formation of and alkenyl perchlorate which is decomposed according to an homolytic process.
- Montheard, Jean-Pierre,Camps, Marcel,Benzaid, Ahmed,Pascal, Jean-Louis
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p. 3483 - 3486
(2007/10/02)
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- Quaternary pilocarpine derivatives as potential acetylcholine antagonists. 3. Alterations in the lactone and imidazole moieties
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In order to investigate the chemical behavior of pilocarpine, as well as the factors which determine its pharmacological activity, systematic and specific structural changes involving the lactone and imidazole moieties have been performed. Series of model compounds with cyclic or open chain structures and a variety of N 3 bonded chains obtained from previously prepared anticholinergic derivatives of pilocarpine have been synthesized. The changes included N 3 chains of different lengths with an acetylcholine like structure, the introduction of nucleophilic groups such as ketoxime, hydroxamic, or both at the side chain, or following hydroxylaminolysis of the lactone, respectively. Specific structural alterations could be obtained by reacting with free hydroxylamine under carefully controlled conditions, and the existence of syn and anti isomers was disclosed in certain cases. The new groups in the pilocarpine derivatives influenced their degree of antagonism to acetylcholine. Several compounds displayed some antidotal activity.
- Ben Bassat,Lavie,Edery,Porath
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p. 928 - 933
(2007/10/13)
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