The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Christopher Hulme - One of the best experts on this subject based on the ideXlab platform.
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Facile, novel two-step syntheses of Benzimidazoles, bis-Benzimidazoles, and bis-benzimidazole-dihydroquinoxalines.
Molecular diversity, 2012Co-Authors: Arthur Y. Shaw, Justin Dietrich, Alexandra P. Cappelli, Gary S. Nichol, Christopher HulmeAbstract:Three scaffolds of Benzimidazoles, bis-Benzimidazoles, and bis-benzimidazole-dihydroquinoxalines were synthesized via Ugi/de-protection/cyclization methodology. Benzimidazole forming ring closure was enabled under microwave irradiation in the presence of 10% TFA/DCE. The methodology demonstrates the utility of 2-(N-Boc-amino)-phenyl-isocyanide for the generation of new molecular diversity.
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two step solution phase synthesis of novel Benzimidazoles utilizing a udc ugi de boc cyclize strategy
Tetrahedron Letters, 2001Co-Authors: Paul Tempest, Vu Van, Samuel Thomas, Zheng Hua, Michael G Kelly, Christopher HulmeAbstract:Abstract The novel solution-phase synthesis of an array of biologically relevant Benzimidazoles in a simple two-step procedure is revealed. Transformations are carried out in excellent yield by condensation of mono-Boc protected ortho-phenylene diamine and supporting Ugi reagents. Subsequent acid treatment and evaporation affords Benzimidazoles in good to excellent yield. The described protocol represents a highly attractive solution-phase procedure for the rapid generation of benzimidazole libraries.
Susanne Rath - One of the best experts on this subject based on the ideXlab platform.
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Leaching of benzimidazole antiparasitics in soil columns and in soil columns amended with sheep excreta
Environmental Science and Pollution Research, 2020Co-Authors: Rafael Silveira Porto, Rafael Silvio Bonilha Pinheiro, Susanne RathAbstract:Benzimidazoles are anthelmintics frequently used in sheep farming due to the high susceptibility of these animals to parasitic diseases. Sheep excreta are often disposed onto soils as a fertilizer, and they may contain benzimidazole residues that can contaminate soil and water. This work aimed to assess the leaching behavior of benzimidazole drugs (albendazole, fenbendazole, and thiabendazole) and their metabolites in two Brazilian soils of different textural classifications (sandy and clay), as well as sheep excreta-amended soils, following the OECD 312 Guidelines. Ewes received a single oral dose of 10 mg kg^−1 b.w. of either albendazole or fenbendazole. The feces were collected at 24, 48, 72, 96, and 120 h post-dose, and the parent drugs and their metabolites extracted using the QuEChERS approach and quantified by UHPLC-MS/MS. For the leaching assays, a benzimidazole solution was directly applied onto the soil columns, or an amount of 5 g of the medicated sheep feces was distributed over the top of the soil columns. In soil samples, Benzimidazoles were extracted by solid-liquid extraction and quantified by UHPLC-MS/MS. For the leaching studies, atrazine was used as a reference substance to determine the relative mobility factor of the analytes of interest. Benzimidazoles were considered slightly to moderately mobile in both soils tested, with a leaching distance of up to 25 cm in a 30-cm soil column. Approximately 3 to 6% of the Benzimidazoles present in ewe feces were able to leach into the soil columns. This finding is of concern since Benzimidazoles are persistent in soil and may pose a risk to soil biota and induce the development of resistant strains of parasites.
Rafael Silveira Porto - One of the best experts on this subject based on the ideXlab platform.
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Leaching of benzimidazole antiparasitics in soil columns and in soil columns amended with sheep excreta
Environmental Science and Pollution Research, 2020Co-Authors: Rafael Silveira Porto, Rafael Silvio Bonilha Pinheiro, Susanne RathAbstract:Benzimidazoles are anthelmintics frequently used in sheep farming due to the high susceptibility of these animals to parasitic diseases. Sheep excreta are often disposed onto soils as a fertilizer, and they may contain benzimidazole residues that can contaminate soil and water. This work aimed to assess the leaching behavior of benzimidazole drugs (albendazole, fenbendazole, and thiabendazole) and their metabolites in two Brazilian soils of different textural classifications (sandy and clay), as well as sheep excreta-amended soils, following the OECD 312 Guidelines. Ewes received a single oral dose of 10 mg kg^−1 b.w. of either albendazole or fenbendazole. The feces were collected at 24, 48, 72, 96, and 120 h post-dose, and the parent drugs and their metabolites extracted using the QuEChERS approach and quantified by UHPLC-MS/MS. For the leaching assays, a benzimidazole solution was directly applied onto the soil columns, or an amount of 5 g of the medicated sheep feces was distributed over the top of the soil columns. In soil samples, Benzimidazoles were extracted by solid-liquid extraction and quantified by UHPLC-MS/MS. For the leaching studies, atrazine was used as a reference substance to determine the relative mobility factor of the analytes of interest. Benzimidazoles were considered slightly to moderately mobile in both soils tested, with a leaching distance of up to 25 cm in a 30-cm soil column. Approximately 3 to 6% of the Benzimidazoles present in ewe feces were able to leach into the soil columns. This finding is of concern since Benzimidazoles are persistent in soil and may pose a risk to soil biota and induce the development of resistant strains of parasites.
Paul Tempest - One of the best experts on this subject based on the ideXlab platform.
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two step solution phase synthesis of novel Benzimidazoles utilizing a udc ugi de boc cyclize strategy
Tetrahedron Letters, 2001Co-Authors: Paul Tempest, Vu Van, Samuel Thomas, Zheng Hua, Michael G Kelly, Christopher HulmeAbstract:Abstract The novel solution-phase synthesis of an array of biologically relevant Benzimidazoles in a simple two-step procedure is revealed. Transformations are carried out in excellent yield by condensation of mono-Boc protected ortho-phenylene diamine and supporting Ugi reagents. Subsequent acid treatment and evaporation affords Benzimidazoles in good to excellent yield. The described protocol represents a highly attractive solution-phase procedure for the rapid generation of benzimidazole libraries.
Elisabeth Von Moos - One of the best experts on this subject based on the ideXlab platform.
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a practical oxone mediated high throughput solution phase synthesis of Benzimidazoles from 1 2 phenylenediamines and aldehydes and its application to preparative scale synthesis
Synthesis, 2003Co-Authors: Pierre L Beaulieu, Bruno Hache, Elisabeth Von MoosAbstract:Addition of oxone ® to a mixture of a 1,2-phenylenedi- amine and an aldehyde in wet DMF at room temperature results in rapid formation of Benzimidazoles under very mild conditions. The reaction is applicable to a wide range of substrates including ali- phatic, aromatic and heteroaromatic aldehydes, and is not signifi- cantly affected by steric or electronic effects. In most cases, crude products are isolated in good to excellent yields (59-95%) and ho- mogeneities (86-99%) by simple precipitation or extraction from the reaction mixture and do not require additional purification. Lim- itations to the scope of this methodology were encountered in cases where aldehydes were sensitive to oxone ® under the acidic reaction conditions. The features of this methodology make it particularly well suited for the high-throughput, solution-phase synthesis of benzimidazole libraries. The low cost and simplicity of this proce- dure makes it equally attractive for preparative-scale syntheses where safety and environmental issues are of greater concern.