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Pál Sohár - One of the best experts on this subject based on the ideXlab platform.
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A Convenient Synthesis of 1,4-Benzothiazepinesfrom 1,3-Benzothiazines via the Ring Transformation of β-Lactam-Condensed1,3-Benzothiazine Derivatives
Synthesis, 2010Co-Authors: Lajos Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:A convenient synthesis was devised for rare 2,3-disubstituted 4,5-dihydro-1,4-benzothiazepines from 2-aryl-4H-1,3-Benzothiazines. The Staudinger reaction of 1,3-Benzothiazines obtained with chloroacetyl chloride selectively furnished trans-monochloroβ-lactam-condensed thiazines. The ring expansion of azeto[2,1-b][1,3]benzothiazin-1-one derivatives with sodium methoxide afforded 1,4-benzothiazepines as the sole product in good yields. The structures of the new molecules were proved by means NMR and IR spectroscopy.
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staudinger and retro staudinger reactions the dichloro β lactam moiety as a useful handle for the synthesis of 4 aryl 2h 1 3 Benzothiazine 1 1 dioxides
Tetrahedron Letters, 2010Co-Authors: L Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:Abstract The dichloro-β-lactam ring, obtained via Staudinger reaction of 4-aryl-2H-1,3-Benzothiazines, proved to be a useful protecting strategy for the synthesis of 4-aryl-2H-1,3-Benzothiazine 1,1-dioxides. After oxidation of the 1,1-dichloroazeto[2,1-c][1,3]-benzothiazin-2-ones, the thiazine ring could be recovered selectively and in good yield by treatment with base. Thus, novel 4-aryl-2H-1,3-Benzothiazine 1,1-dioxides were obtained efficiently.
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Synthesis of quinazolino-1,3-Benzothiazine derivatives
Acta pharmaceutica Hungarica, 1994Co-Authors: János Szabó, Lajos Fodor, Gábor Bernáth, E. Bani‐akoto, György Dombi, Pál SohárAbstract:The ring-closure reactions of N-(3,4-dimethoxyphenylthio-methyl)-2-nitrobenzamide derivatives 5a,b with phosphoryl chloride gave 4-(2'-nitrophenyl)-2H-1,3-Benzothiazine derivatives 7a,b, which on reduction yielded 4-(2'-aminophenyl)-3,4-dihydro-2H-1,3-Benzothiazines 8a,b. Reaction of these compounds with phosgene led to the derivatives 9a,b of a new heterocyclic ring system, 6H,8H-quinazolino[3,4-c] [1,3]Benzothiazine. The structures of the title compounds were proved by their ir and nmr (1H, 13C) spectra.
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Synthesis of quinazolino‐1,3‐Benzothiazine derivatives
Journal of Heterocyclic Chemistry, 1992Co-Authors: János Szabó, Lajos Fodor, Gábor Bernáth, E. Bani‐akoto, György Dombi, Pál SohárAbstract:The ring-closure reactions of N-(3,4-dimethoxyphenylthiomethyl)-2-nitrobenzamide derivatives 5a,b with phosphoryl chloride gave 4-(2-nitrophenyl)-2H-1,3-Benzothiazine derivatives 7a,b, which on reduction yielded 4-(2'-aminophenyl)-3,4-dihydro-2H-1,3-Benzothiazines 8a,b. Reaction of these compounds with phosgene led to a new heterocyclic ring system, 6H,8H-quinazolino[3,4-c][1,3]Benzothiazine derivatives 9a,b. The structures of the title compounds were proved via their ir and nmr ( 1 H, 13 C) spectra
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Synthesis of partially saturated N-substituted 4H-3,1-Benzothiazine-2(1H)-thiones
Monatshefte für Chemie Chemical Monthly, 1991Co-Authors: Pál Perjési, Pál SohárAbstract:Die säurekatalysierte Reaktion von 2-Arylidencyclohexanonen 1 mit N-substituierten Dithiocarbaminsäure 2 ergab die offenkettigen Additionsprodukte 3 und 4 . Die Dehydratation von 3 und 4 führte ausschließlich zu einem der drei möglichen N-substituierten 4 H -3,1-Benzothiazin-2(1 H )-thion-Isomeren 5 und 6 . Acid-catalyzed reaction of 2-arylidenecyclohexanones 1 with N-substituted dithiocarbamic acids 2 gave open-chain addition products 3 and 4 . Dehydration of 3 and 4 afforded only one of the three possible isomeric N-substituted 4 H -3,1-Benzothiazine-2(1 H )-thiones 5 and 6 .
D. C. Gautam - One of the best experts on this subject based on the ideXlab platform.
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An Efficient Synthesis and Antimicrobial Studies of Bioactive 4H-1,4-Benzothiazine and Their Sulfone Derivatives
Phosphorus Sulfur and Silicon and the Related Elements, 2013Co-Authors: Naveen Gautam, Yogesh Dixit, Rahul Dixit, Sudesh Kumar Gupta, D. C. GautamAbstract:Abstract 4H-1,4-Benzothiazines were prepared by condensation followed by oxidative cyclization of substituted 2-aminobenzenethiols with β-diketones in dimethylsulfoxide. On refluxing with 30% hydrogen peroxide in glacial acetic acid, 4H-1,4-Benzothiazines yielded 4H-1,4-Benzothiazine-1,1-dioxides. Structural evaluation has been done by spectral and elemental analysis. All the synthesized compounds were evaluated for their antibacterial and antifungal activity and all these have shown moderate to high activity against the test microbes. Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures and tables.
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An efficient synthesis and biological study of substituted 8-chloro-5-methoxy/8-chloro-4H-1,4-Benzothiazines, their sulphones and ribofuranosides
Journal of Chemical Sciences, 2013Co-Authors: Nishidha Khandelwal, Naveen Gautam, Abhilasha, D. C. GautamAbstract:8-Chloro-5-methoxy/8-chloro-4H-1,4-Benzothiazines were synthesized by condensation followed by oxidative cyclisation of 2-amino-6-chloro-3-methoxy/2-amino-3-chlorobenzenethiol with β–diketones/β–ketoesters in the presence of dimethyl sulphoxide. By treating 4H-1,4-Benzothiazines with 30% hydrogen peroxide in glacial acetic acid, 4H-1,4-Benzothiazine-1,1-dioxides (sulphones) were synthesized. The 4H-1,4-Benzothiazines have also been used as a base to prepare ribofuranosides by the reaction with β–D-ribofuranose-1-acetate-2,3,5-tribenzoate. All the synthesized compounds have been characterized by spectral and elemental analysis and have been examined for antimicrobial and anthelmintic activity.
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an efficient synthesis and biological study of substituted 8 chloro 5 methoxy 8 chloro 4h 1 4 Benzothiazines their sulphones and ribofuranosides
Journal of Chemical Sciences, 2013Co-Authors: Nishidha Khandelwal, Naveen Gautam, D. C. GautamAbstract:8-Chloro-5-methoxy/8-chloro-4H-1,4-Benzothiazines were synthesized by condensation followed by oxidative cyclisation of 2-amino-6-chloro-3-methoxy/2-amino-3-chlorobenzenethiol with β–diketones/β–ketoesters in the presence of dimethyl sulphoxide. By treating 4H-1,4-Benzothiazines with 30% hydrogen peroxide in glacial acetic acid, 4H-1,4-Benzothiazine-1,1-dioxides (sulphones) were synthesized. The 4H-1,4-Benzothiazines have also been used as a base to prepare ribofuranosides by the reaction with β–D-ribofuranose-1-acetate-2,3,5-tribenzoate. All the synthesized compounds have been characterized by spectral and elemental analysis and have been examined for antimicrobial and anthelmintic activity.
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Synthesis And Biological Activity Of Substituted 4H-1,4-Benzothiazines, Their Sulfones, And Ribofuranosides
Nucleosides nucleotides & nucleic acids, 2013Co-Authors: Kshamta Goyal, Naveen Gautam, Nishidha Khandelwal, D. C. GautamAbstract:The present article describes the synthesis of new 4H-1,4-Benzothiazines via condensation and oxidative cyclization of substituted 2-aminobenzenethiols with β-diketones/β-ketoesters in dimethyl sulfoxide. The oxidation of these synthesized 4H-1,4-Benzothiazines with 30% hydrogen peroxide in glacial acetic acid yielded 4H-1,4-Benzothiazine sulfones and the reaction of these synthesized Benzothiazines with sugar (β-D-ribofuranose-1-acetate-2,3,5-tribenzoate) afforded the new ribofuranosides. These compounds were evaluated for their antioxidant and antimicrobial activities (using broth microdilution method). The structural assignments of the synthesized compounds were made on the basis of elemental analyses and spectroscopic data.
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Synthesis, Characterization and Pharmacological Importance of Novel 4H-1,4- Benzothiazines and their Sulfone Analogues
2013Co-Authors: Shikha Agarwal, Naveen Gautam, Neha Ajmera, Neetu Kumari, Dinesh K. Agarwal, Sudesh Gupta, D. C. GautamAbstract:H-1,4-Benzothiazines and its derivatives are potential pharmacologically and industrially useful agents. They were prepared by condensation followed by oxidative cyclization of 2-amino-4,6-dimethylbenzenethiol with varied β- diketones/β-ketoesters in dimethyl sulfoxide. On refluxing with H2O2 in glacial acetic acid, the substituted 4H-1,4- Benzothiazines yielded 4H-1,4-Benzothiazine-1,1-dioxides (sulfones). These compounds were evaluated for antioxidant activity by DPPH and ABTS assay and the antimicrobial properties were investigated against various strains of bacteria (Coagulase negative Staphylococci, Coagulase positive Staphylococci, Enterobacter) and fungi (Candida albicans) using Paper disc method. The structures of the compounds have been confirmed by spectral and elemental analysis.
Peter Csomos - One of the best experts on this subject based on the ideXlab platform.
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A Convenient Synthesis of 1,4-Benzothiazepinesfrom 1,3-Benzothiazines via the Ring Transformation of β-Lactam-Condensed1,3-Benzothiazine Derivatives
Synthesis, 2010Co-Authors: Lajos Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:A convenient synthesis was devised for rare 2,3-disubstituted 4,5-dihydro-1,4-benzothiazepines from 2-aryl-4H-1,3-Benzothiazines. The Staudinger reaction of 1,3-Benzothiazines obtained with chloroacetyl chloride selectively furnished trans-monochloroβ-lactam-condensed thiazines. The ring expansion of azeto[2,1-b][1,3]benzothiazin-1-one derivatives with sodium methoxide afforded 1,4-benzothiazepines as the sole product in good yields. The structures of the new molecules were proved by means NMR and IR spectroscopy.
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staudinger and retro staudinger reactions the dichloro β lactam moiety as a useful handle for the synthesis of 4 aryl 2h 1 3 Benzothiazine 1 1 dioxides
Tetrahedron Letters, 2010Co-Authors: L Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:Abstract The dichloro-β-lactam ring, obtained via Staudinger reaction of 4-aryl-2H-1,3-Benzothiazines, proved to be a useful protecting strategy for the synthesis of 4-aryl-2H-1,3-Benzothiazine 1,1-dioxides. After oxidation of the 1,1-dichloroazeto[2,1-c][1,3]-benzothiazin-2-ones, the thiazine ring could be recovered selectively and in good yield by treatment with base. Thus, novel 4-aryl-2H-1,3-Benzothiazine 1,1-dioxides were obtained efficiently.
Antal Csámpai - One of the best experts on this subject based on the ideXlab platform.
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A Convenient Synthesis of 1,4-Benzothiazepinesfrom 1,3-Benzothiazines via the Ring Transformation of β-Lactam-Condensed1,3-Benzothiazine Derivatives
Synthesis, 2010Co-Authors: Lajos Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:A convenient synthesis was devised for rare 2,3-disubstituted 4,5-dihydro-1,4-benzothiazepines from 2-aryl-4H-1,3-Benzothiazines. The Staudinger reaction of 1,3-Benzothiazines obtained with chloroacetyl chloride selectively furnished trans-monochloroβ-lactam-condensed thiazines. The ring expansion of azeto[2,1-b][1,3]benzothiazin-1-one derivatives with sodium methoxide afforded 1,4-benzothiazepines as the sole product in good yields. The structures of the new molecules were proved by means NMR and IR spectroscopy.
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staudinger and retro staudinger reactions the dichloro β lactam moiety as a useful handle for the synthesis of 4 aryl 2h 1 3 Benzothiazine 1 1 dioxides
Tetrahedron Letters, 2010Co-Authors: L Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:Abstract The dichloro-β-lactam ring, obtained via Staudinger reaction of 4-aryl-2H-1,3-Benzothiazines, proved to be a useful protecting strategy for the synthesis of 4-aryl-2H-1,3-Benzothiazine 1,1-dioxides. After oxidation of the 1,1-dichloroazeto[2,1-c][1,3]-benzothiazin-2-ones, the thiazine ring could be recovered selectively and in good yield by treatment with base. Thus, novel 4-aryl-2H-1,3-Benzothiazine 1,1-dioxides were obtained efficiently.
L Fodor - One of the best experts on this subject based on the ideXlab platform.
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staudinger and retro staudinger reactions the dichloro β lactam moiety as a useful handle for the synthesis of 4 aryl 2h 1 3 Benzothiazine 1 1 dioxides
Tetrahedron Letters, 2010Co-Authors: L Fodor, Peter Csomos, Antal Csámpai, Pál SohárAbstract:Abstract The dichloro-β-lactam ring, obtained via Staudinger reaction of 4-aryl-2H-1,3-Benzothiazines, proved to be a useful protecting strategy for the synthesis of 4-aryl-2H-1,3-Benzothiazine 1,1-dioxides. After oxidation of the 1,1-dichloroazeto[2,1-c][1,3]-benzothiazin-2-ones, the thiazine ring could be recovered selectively and in good yield by treatment with base. Thus, novel 4-aryl-2H-1,3-Benzothiazine 1,1-dioxides were obtained efficiently.