- PROCESS FOR THE SYNTHESIS OF S-BEFLUBUTAMID USING ASYMMETRIC HYDROGENATION
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Disclosed is a method for preparing compound S-1, from compound S-5; wherein compound S-5 is prepared by treating compound 2 with a tertiary amine and a hydrogen source in the presence of a chiral complex.
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Page/Page column 27
(2021/08/20)
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- α-Bromoacrylic Acids as C1 Insertion Units for Palladium-Catalyzed Decarboxylative Synthesis of Diverse Dibenzofulvenes
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Herein α-bromoacrylic acids have been employed as C1 insertion units to achieve the palladium-catalyzed [4 + 1] annulation of 2-iodobiphenyls, which provides an efficient platform for the construction of diverse dibenzofulvenes. This protocol enables the formation of double C(aryl)-C(vinyl) bonds via a C(vinyl)-Br bond cleavage and decarboxylation. It is particularly noteworthy that the method features a broad substrate scope, and various interesting frameworks, such as bridged ring, fused (hetero)aromatic ring, and divinylbenzene, can be successfully incorporated into the products.
- Zhang, Minghao,Deng, Wenbo,Sun, Mingjie,Zhou, Liwei,Deng, Guobo,Liang, Yun,Yang, Yuan
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supporting information
p. 5744 - 5749
(2021/08/18)
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- Reaction of Vinyl Aziridines with Arynes: Synthesis of Benzazepines and Branched Allyl Fluorides
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We report the cycloaddition between vinyl aziridines and arynes. Depending on the reaction conditions and the choice of the aryne precursor, the aziridinium intermediate can be trapped through two distinct mechanistic pathways. The first one proceeds through a formal [5+2] cycloaddition to furnish valuable multi-substituted benzazepines. In the second pathway, the aziridinium is intercepted by a fluoride ion to afford allylic fluorides in good yields. Both reactions proceed stereospecifically and furnish enantiopure benzazepines and allylic fluorides.
- Kaldas, Sherif J.,Kran, Eva,Mück-Lichtenfeld, Christian,Yudin, Andrei K.,Studer, Armido
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supporting information
p. 1501 - 1505
(2020/02/05)
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- Synthesis and biological evaluation of a series of benzoxazole/ benzothiazole-containing 2,3-dihydrobenzo[b][1,4]dioxine derivatives as potential antidepressants
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A series of benzoxazole/benzothiazole-2,3-dihydrobenzo[b][1,4]dioxine derivatives (5a-5d and 8a-8j) was synthesized. Compounds were evaluated for binding affinities at the 5-HT1A and 5-HT2A receptors. Antidepressant activities of the compounds were screened using the forced swimming test (FST) and the tail suspension test (TST). The results indicated that the compounds exhibited high affinities for the 5-HT1A and 5-HT2A receptors and showed a marked antidepressant-like activity. Compound 8g exhibited high affinities for the 5-HT1A (Ki = 17 nM) and 5-HT2A (Ki = 0.71 nM) receptors; it also produced a decrease of the immobility time and exhibited potent antidepressant-like effects in the FST and TST in mice.
- Wang, Songlin,Chen, Yin,Zhao, Song,Xu, Xiangqing,Liu, Xin,Liu, Bi-Feng,Zhang, Guisen
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p. 1766 - 1770
(2014/04/17)
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- Anionic [4+3] heteroannulation of 2-azidoacrylates: A modular synthesis of 2-benzazepin-1-ones
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2-Azidoacrylates undergo [4+3] annulation with phthalides under anionic conditions at low temperatures to furnish 5-hydroxy-2-benzazepinones, the formation of which represents a new concept for the construction of azepines as well as a new reactivity of 2-azidoacrylates.
- Dinda, Bidyut Kumar,Jana, Amit Kumar,Mal, Dipakranjan
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supporting information; experimental part
p. 3999 - 4001
(2012/06/01)
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- Dioxane dibromide-mediated solvent-free synthesis of vicinal dibromides
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Structurally varied vicinal dibromides have been synthesized in high yield and good purity through highly stereoselective anti-addition of bromine across the olefinic linkages using dioxane dibromide (DD) under solvent-free conditions. Copyright Taylor & Francis Group, LLC.
- Chaudhuri, Subrata Kumar,Roy, Sanchita,Saha, Manabendra,Bhar, Sanjay
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p. 271 - 274
(2007/10/03)
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- A thermal cascade route to pyrroloisoindolone and pyrroloimidazolones
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(Chemical Equation Presented) Flash vacuum pyrolysis (FVP) of indol-1-ylacrylate derivatives 11 and 15 or the isomeric indol-3-ylacrylates 21, 22, and 24 at 925°C (0.05 Torr) provides pyrrolo[1,2-a]indol-3-ones 2, 18, 28, and 29 in 53-90% yield by a cascade mechanism that involves a sigmatropic migration, elimination, electrocyclization sequence. Pyrrolo[1,2-a]imidazol-5- ones 3 and pyrrolo[1,2-c]imidazol-5-ones 4 were similarly obtained by FVP of corresponding 2,5-unsubstituted imidazol-1-ylacrylates (e.g., 33), with the former isomer predominating in ca. 80:20 ratio. Migration to the 2-position is therefore favored in the initial sigmatropic shift. FVP of 2-substituted imidazol-1-ylacrylates 35, 37, and 51 (825-875°C) instead give pyrrolo[1,2-c]imidazol-5-ones 56-58 only (88-91%), and that of 4,5-disubstituted imidazol-1-ylacrylates 39 and 41 (825-850°C) provide pyrrolo[1,2-a] imidazol-5-ones 59 and 60 exclusively (93-95%), and thus the selectivity of the initial shift can be controlled by the presence of substituents on the imidazole 2- and 5-positions. FVP of the benzimidazole analogues 61 and 62 at 950°C gave the pyrrolo[1,2-a]benzimidazol-1-ones 6 (71%) and 63 (36%), respectively.
- McNab, Hamish,Tyas, Richard G.
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p. 8760 - 8769
(2008/03/13)
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- NOVEL CRYSTALLINE FORMS OF ANTIDIABETIC COMPOUNDS
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Novel crystalline forms of two indole compounds connected to phenoxyalkylcarboxylic acid groups are selective PPAR gamma partial agonists that are useful in the treatment of type 2 diabetes, hyperglycemia, obesity, dyslipidemia, and the metabolic syndrome. The novel crystal forms include a crystalline free acid dihydrate and crystalline free acid anhydrate of one compound and several crystalline forms of the free acid and the sodium salt of the second compound. The invention also relates to pharmaceutical compositions comprising these novel crystal forms, processes to prepare the crystal forms and their pharmaceutical compositions, and uses of the crystal forms in the treatment of type 2 diabetes and other PPAR gamma modulated diseases.
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Page/Page column 16-17
(2010/11/23)
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- New palladium(II)-catalyzed asymmetric 1,2-dibromo synthesis
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(Matrix presented) The oxidation of olefins by chiral monometallic and bimetallic Pd(II)-Cu(II) catalysts in bromide-containing aqueous-THF reaction mixtures produced chiral 1,2-dibromides. With α-olefins, the ee's were about 95% while most of the interna
- El-Qisairi, Arab K.,Qaseer, Hanan A.,Katsigras, George,Lorenzi, Philip,Trivedi, Unnati,Tracz, Sylvia,Hartman, Amy,Miller, Jason A.,Henry, Patrick M.
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p. 439 - 441
(2007/10/03)
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- Bicycloannulation of α-Bromo α,β-Unsaturated Esters; Synthesis of the Tricyclo1,5>decane Framework and Its Congeners
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Reactions of the kinetic enolates 6 of 1-acetylcyclohexenes 5 with α-bromo α,β-unsaturated esters 7 proceed via a successive Michael-Michael-substitution pathway to give methyl 2-oxotricyclo1,5>decane-5-carboxylates 8 in a one-pot operation.
- Hagiwara, Hisashiro,Abe, Futoshi,Uda, Hisashi
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p. 2651 - 2656
(2007/10/02)
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- The Compounds Related to 3-(1-Imidazolyl)-2-alken-1-ones. Preparation and Reactions
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Compounds related to 3-(1-imidazolyl)-2-alken-1-ones, 3-(1-imidazolyl)-2-alkenoic acid derivatives and 2-alken-1-ones having heterocycles on the C-3 carbon were prepared.The reaction of nucleophiles with these compounds was also discussed.
- Kashima, Choji,Tajima, Tadakuni,Omote, Yoshimori
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p. 171 - 176
(2007/10/02)
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- Kinetics and Mechanism of Bromine Addition to Derivatives of Unsaturated Aliphatic Carboxylic Acids in Aqueous Solution
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This paper deals with the kinetics of bromine addition to unsaturated compounds in presence of added bromide ions at 22, 30, 38, 46, and 54 deg C.The substrates used were acrylamide (AAm), methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), t-butyl acrylate (tBA), methacrylamide (MAAm), methyl methacrylate (MMA), ethyl methacrylate (EMA), methyl crotonate (MC), and ethyl crotonate (EC).The kinetics was followed potentiometrically.The activation parameters (ΔH*, ΔS*, and ΔG*) were calculated and compared.Estimation of product ratio of bromohydrin to dibromide showed the absence of any correlation of the product formation with reactivity of the substrates.The observed parameters are discussed in relation to the proposed reaction mechanisms.
- Mohamed Farook, Syed Ahamed,Viswanathan, Seshaiyer,Ganesan, Ramachandran
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p. 1394 - 1400
(2007/10/02)
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- ADDITION OF CHLORINE, BROMINE AND BROMINE CHLORIDE TO SOME α,β-UNSATURATED METHYL ESTERS
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The additions of chlorine, bromine and bromine chloride to trans methyl 2-butenoate 1, trans methyl 2-methyl-2-butenoate 2 and methyl 3-methyl-2-butenoate 3 under ionic conditions were studied.Bromine chloride addition always gave as a major regioisomer the 2-bromo-3-chloro compound, almost quantitatively in the case of 3.The mechanism of bromonium ion ring-opening (SN1 or SN2) is discussed with respect to the double bond substitution and regioisomer proportions.The dihalo products were identified by MS, 1H and 13C NMR.
- Korhonen, Ilpo O. O.,Pitkaenen, Maija,Korvola, Jorma N. J.
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p. 2837 - 2841
(2007/10/02)
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- Carbon-13 NMR Spectra of Bromine-containing Esters
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13CHBrCOOR fragments of bromine-containing mono- and dicarboxylates show 13C NMR signals in the range 38-45 ppm, at 12-15 ppm to high field of their chloro analogues.The introduction of one bromine atom into the α-CH2 group causes a 6-13 ppm shift of the carbon signal, depending on the type of ester.The replacement of H with Br in 13C2H2(COOR)2 has only a negligible influence on the 13CH2 signal position.The 13CBr2COOR fragment signals appear in the range 40-54 ppm. 13C NMR data, including the chemical shift values, signal multiplicities and spin-spin couplings, make possible the identification of isomers present in isomer mixtures of bromine-containing esters.The 13COOR chemical shifts of diastereomers of α,β-dibromoesters differ noticeably from each other, and the 13C NMR spectra can thus be used to supply preliminary information about the stereochemistry of bromine addition to α,β-unsaturated acids.
- Velichko, F. K.,Dostovalova, V. I.,Vinogradova, L. V.,Freidlina, R Kh.
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p. 442 - 446
(2007/10/02)
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