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Nilo Zanatta - One of the best experts on this subject based on the ideXlab platform.
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Synthetic Versatility of β-Alkoxyvinyl Trichloromethyl Ketones for Obtaining [1,2,4]Triazolo[1,5-a]pyrimidines
Synthesis, 2018Co-Authors: Laura A. Souza, Helio G. Bonacorso, Marcos A. P. Martins, Josiane M. Dos Santos, Mateus Mittersteiner, Valquiria P. Andrade, Marcio M. Lobo, Felipe Ribeiro Botelho Santos, Adailton J. Bortoluzzi, Nilo ZanattaAbstract:The synthetic versatility of 4-alkoxy-4-alkyl/aryl-1,1,1-trichloroalk-3-en-2-ones (enones) for the synthesis of [1,2,4]triazolo[1,5-a]pyrimidines, in which the Trichloromethyl Group is either maintained or eliminated from the product by simply controlling the reaction medium, is reported. These enones react with 3-amino-1H-1,2,4-triazoles under acidic conditions to furnish exclusively 7-(Trichloromethyl)-[1,2,4]triazolo[1,5-a]pyrimidines, whereas under basic conditions [1,2,4]triazolo[1,5-a]pyrimidin-5/7(1H)-ones are obtained with elimination of the Trichloromethyl Group. The regioselectivity of the reactions performed under basic conditions is highly influenced by the substituents present in the starting enones. Twenty-one examples are synthesized using these two methodologies, with yields of up to 86%.
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Synthesis, antimicrobial activity, and QSAR studies of furan-3-carboxamides.
Bioorganic & medicinal chemistry, 2007Co-Authors: Nilo Zanatta, Sydney Hartz Alves, Helena S. Coelho, Deise M. Borchhardt, Pablo Machado, Kelen M. Flores, Fabio M. Da Silva, Tatiana B. Spader, Jânio Morais Santúrio, Helio G. BonacorsoAbstract:The synthesis and characterization of a new series of furan-3-carboxamides, from the aromatization of 4-trichloroacetyl-2,3-dihydrofuran to 3-trichloroacetyl furan followed by nucleophilic displacement of the Trichloromethyl Group or the corresponding carboxylic acid chloride by nitrogen-containing compounds, is presented. Preliminary in vitro antimicrobial activity of the title compounds was assessed against a panel of microorganisms including yeast, filamentous fungi, bacteria, and alga. Some of the furan-3-carboxamides exhibited significant in vitro antimicrobial activity. QSAR investigation was applied to find a correlation between the different physicochemical parameters of the compounds studied and their biological activity.
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Convenient synthesis of furan-3-carboxylic acid and derivatives
Tetrahedron Letters, 2004Co-Authors: Nilo Zanatta, Helio G. Bonacorso, Débora Faoro, Simone C. Silva, Marcos A. P. MartinsAbstract:Abstract A convenient synthesis of furan-3-carboxylic acid and derivatives from aromatization of 4-trichloroacetyl-2,3-dihydrofuran followed by nucleophilic displacement of the Trichloromethyl Group by hydroxide, alcohols, and amines, is presented.
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1,1,1-Trichloro-4,4-diethoxy-3-buten-2-one and its trichloroacetylacetate derivatives: Synthesis and applications in regiospecific preparation of azoles
Synthesis, 2003Co-Authors: Marcos A. P. Martins, Adilson P Sinhorin, Helio G. Bonacorso, Nilo Zanatta, Wilson Cunico, Claudio M. P. Pereira, Sidnei Moura, Nilo E. K. Zimmermann, Alex C. F. FloresAbstract:The synthesis of 1,1,1-trichloro-4,4-diethoxy-3-buten-2-one and three trichloroacetylacetate derivatives from the acylation reaction of respective trialkyl orthoacetates and orthopropionates with trichloroacetyl chloride in good yields, is reported. The title compounds were used for the regiospecific preparation of two isoxazoles and five pyrazoles in the cyclocondensation with hydroxylamine and hydrazines, respectively. The transformation of the Trichloromethyl Group under mild conditions into carboxylic Groups is also described.
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A Convenient Preparation of 4-Methyl- and 4-Phenylseleno-1,1,1-trihalo-3-alken-2-ones and their Usefulness in the Synthesis of 3-Trihalomethylisoselenazoles
Synthesis, 2002Co-Authors: Marcos A. P. Martins, Giovani P Bastos, Adilson P Sinhorin, Helio G. Bonacorso, Nilo E. K. Zimmermann, Nilo ZanattaAbstract:A convenient synthesis of fourteen 4-methyl- and 4-phenylseleno-1,1,1-trihalo-3-alken-2-ones [CX 3 C(O)CH=CR 1 SeR. where X = F, Cl; R = Me, Ph; and R 1 = H, alkyl, aryl from the reaction of the corresponding 4-methoxy-1,1,1-trihalo-3-alken-2-ones with methyl- or phenylselenols in the presence of boron trifluoride etherate is reported. The reaction of 4-methylseleno- 1,1,1-trihalo-3-alken-2-ones with bromine and ammonia lead to 3-trihalomethylisoselenazoles in good yields. The usefulness of the Trichloromethyl Group as a carboxyl Group precursor was demonstrated by the conversion of 5-ethyl-3-Trichloromethylisoselenazole to 5-ethyl-3-carboxyisoselenazole acid.
Helio G. Bonacorso - One of the best experts on this subject based on the ideXlab platform.
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Synthetic Versatility of β-Alkoxyvinyl Trichloromethyl Ketones for Obtaining [1,2,4]Triazolo[1,5-a]pyrimidines
Synthesis, 2018Co-Authors: Laura A. Souza, Helio G. Bonacorso, Marcos A. P. Martins, Josiane M. Dos Santos, Mateus Mittersteiner, Valquiria P. Andrade, Marcio M. Lobo, Felipe Ribeiro Botelho Santos, Adailton J. Bortoluzzi, Nilo ZanattaAbstract:The synthetic versatility of 4-alkoxy-4-alkyl/aryl-1,1,1-trichloroalk-3-en-2-ones (enones) for the synthesis of [1,2,4]triazolo[1,5-a]pyrimidines, in which the Trichloromethyl Group is either maintained or eliminated from the product by simply controlling the reaction medium, is reported. These enones react with 3-amino-1H-1,2,4-triazoles under acidic conditions to furnish exclusively 7-(Trichloromethyl)-[1,2,4]triazolo[1,5-a]pyrimidines, whereas under basic conditions [1,2,4]triazolo[1,5-a]pyrimidin-5/7(1H)-ones are obtained with elimination of the Trichloromethyl Group. The regioselectivity of the reactions performed under basic conditions is highly influenced by the substituents present in the starting enones. Twenty-one examples are synthesized using these two methodologies, with yields of up to 86%.
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Highly regioselective Synthesis of 1-(5-Trichloromethyl -5-hydroxy - 4,5-dihydroisoxazole-3-methylene)-5-phenyl-1H-1,2,3-triazoles
2008Co-Authors: Marcos A. P. Martins, Adilson P Sinhorin, Helio G. Bonacorso, Daniel J. Emmerich, Marcelo Rossatto, Clarissa P. Frizzo, Nilo ZanataAbstract:A convenient method to obtain a series of 1-(5-hydroxy-5-Trichloromethyl-4,5-dihydroisoxazole3-methylene)-5-phenyl-1H-1,2,3-triazoles by a regiospecific cycloaddition reaction of phenyl acetylenes [Ph–C≡C–R, where R = C(O)CCl3, C(O)CHCl2, C(OH)2CF3, CCl3 and 3methylisoxazolo-5-carbonyl] with 5-hydroxy-5-Trichloromethyl-4,5-dihydroisoxazole-3methylene azide is reported, in moderate to good yields (67-80%). From the reaction of a 4trichloroacetyltriazole derivative with methanol or methylamine it was possible to obtain the corresponding ester and amide derivatives, respectively, by substitution of the Trichloromethyl Group.
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Synthesis, antimicrobial activity, and QSAR studies of furan-3-carboxamides.
Bioorganic & medicinal chemistry, 2007Co-Authors: Nilo Zanatta, Sydney Hartz Alves, Helena S. Coelho, Deise M. Borchhardt, Pablo Machado, Kelen M. Flores, Fabio M. Da Silva, Tatiana B. Spader, Jânio Morais Santúrio, Helio G. BonacorsoAbstract:The synthesis and characterization of a new series of furan-3-carboxamides, from the aromatization of 4-trichloroacetyl-2,3-dihydrofuran to 3-trichloroacetyl furan followed by nucleophilic displacement of the Trichloromethyl Group or the corresponding carboxylic acid chloride by nitrogen-containing compounds, is presented. Preliminary in vitro antimicrobial activity of the title compounds was assessed against a panel of microorganisms including yeast, filamentous fungi, bacteria, and alga. Some of the furan-3-carboxamides exhibited significant in vitro antimicrobial activity. QSAR investigation was applied to find a correlation between the different physicochemical parameters of the compounds studied and their biological activity.
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One‐Pot Synthesis of Pyrazole‐5(3)‐carboxyamides
Synthetic Communications, 2004Co-Authors: Marcos A. P. Martins, Adilson P Sinhorin, Daniel J. Emmerich, Paulo Beck, Wilson Cunico, Claudio M. P. Pereira, Sergio Brondani, Rodrigo L. Peres, Marcos V. M. Teixeira, Helio G. BonacorsoAbstract:Abstract A convenient one‐pot synthesis of eight pyrazole‐5(3)‐carboxyamides from the reaction of the 5(3)‐Trichloromethylpyrazoles with amines, in good yield, is reported. These reactions show that the Trichloromethyl Group is a convenient precursor to carboxyamide Groups.
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Convenient synthesis of furan-3-carboxylic acid and derivatives
Tetrahedron Letters, 2004Co-Authors: Nilo Zanatta, Helio G. Bonacorso, Débora Faoro, Simone C. Silva, Marcos A. P. MartinsAbstract:Abstract A convenient synthesis of furan-3-carboxylic acid and derivatives from aromatization of 4-trichloroacetyl-2,3-dihydrofuran followed by nucleophilic displacement of the Trichloromethyl Group by hydroxide, alcohols, and amines, is presented.
Marcos A. P. Martins - One of the best experts on this subject based on the ideXlab platform.
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Synthetic Versatility of β-Alkoxyvinyl Trichloromethyl Ketones for Obtaining [1,2,4]Triazolo[1,5-a]pyrimidines
Synthesis, 2018Co-Authors: Laura A. Souza, Helio G. Bonacorso, Marcos A. P. Martins, Josiane M. Dos Santos, Mateus Mittersteiner, Valquiria P. Andrade, Marcio M. Lobo, Felipe Ribeiro Botelho Santos, Adailton J. Bortoluzzi, Nilo ZanattaAbstract:The synthetic versatility of 4-alkoxy-4-alkyl/aryl-1,1,1-trichloroalk-3-en-2-ones (enones) for the synthesis of [1,2,4]triazolo[1,5-a]pyrimidines, in which the Trichloromethyl Group is either maintained or eliminated from the product by simply controlling the reaction medium, is reported. These enones react with 3-amino-1H-1,2,4-triazoles under acidic conditions to furnish exclusively 7-(Trichloromethyl)-[1,2,4]triazolo[1,5-a]pyrimidines, whereas under basic conditions [1,2,4]triazolo[1,5-a]pyrimidin-5/7(1H)-ones are obtained with elimination of the Trichloromethyl Group. The regioselectivity of the reactions performed under basic conditions is highly influenced by the substituents present in the starting enones. Twenty-one examples are synthesized using these two methodologies, with yields of up to 86%.
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Highly regioselective Synthesis of 1-(5-Trichloromethyl -5-hydroxy - 4,5-dihydroisoxazole-3-methylene)-5-phenyl-1H-1,2,3-triazoles
2008Co-Authors: Marcos A. P. Martins, Adilson P Sinhorin, Helio G. Bonacorso, Daniel J. Emmerich, Marcelo Rossatto, Clarissa P. Frizzo, Nilo ZanataAbstract:A convenient method to obtain a series of 1-(5-hydroxy-5-Trichloromethyl-4,5-dihydroisoxazole3-methylene)-5-phenyl-1H-1,2,3-triazoles by a regiospecific cycloaddition reaction of phenyl acetylenes [Ph–C≡C–R, where R = C(O)CCl3, C(O)CHCl2, C(OH)2CF3, CCl3 and 3methylisoxazolo-5-carbonyl] with 5-hydroxy-5-Trichloromethyl-4,5-dihydroisoxazole-3methylene azide is reported, in moderate to good yields (67-80%). From the reaction of a 4trichloroacetyltriazole derivative with methanol or methylamine it was possible to obtain the corresponding ester and amide derivatives, respectively, by substitution of the Trichloromethyl Group.
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One‐Pot Synthesis of Pyrazole‐5(3)‐carboxyamides
Synthetic Communications, 2004Co-Authors: Marcos A. P. Martins, Adilson P Sinhorin, Daniel J. Emmerich, Paulo Beck, Wilson Cunico, Claudio M. P. Pereira, Sergio Brondani, Rodrigo L. Peres, Marcos V. M. Teixeira, Helio G. BonacorsoAbstract:Abstract A convenient one‐pot synthesis of eight pyrazole‐5(3)‐carboxyamides from the reaction of the 5(3)‐Trichloromethylpyrazoles with amines, in good yield, is reported. These reactions show that the Trichloromethyl Group is a convenient precursor to carboxyamide Groups.
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Convenient synthesis of furan-3-carboxylic acid and derivatives
Tetrahedron Letters, 2004Co-Authors: Nilo Zanatta, Helio G. Bonacorso, Débora Faoro, Simone C. Silva, Marcos A. P. MartinsAbstract:Abstract A convenient synthesis of furan-3-carboxylic acid and derivatives from aromatization of 4-trichloroacetyl-2,3-dihydrofuran followed by nucleophilic displacement of the Trichloromethyl Group by hydroxide, alcohols, and amines, is presented.
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1,1,1-Trichloro-4,4-diethoxy-3-buten-2-one and its trichloroacetylacetate derivatives: Synthesis and applications in regiospecific preparation of azoles
Synthesis, 2003Co-Authors: Marcos A. P. Martins, Adilson P Sinhorin, Helio G. Bonacorso, Nilo Zanatta, Wilson Cunico, Claudio M. P. Pereira, Sidnei Moura, Nilo E. K. Zimmermann, Alex C. F. FloresAbstract:The synthesis of 1,1,1-trichloro-4,4-diethoxy-3-buten-2-one and three trichloroacetylacetate derivatives from the acylation reaction of respective trialkyl orthoacetates and orthopropionates with trichloroacetyl chloride in good yields, is reported. The title compounds were used for the regiospecific preparation of two isoxazoles and five pyrazoles in the cyclocondensation with hydroxylamine and hydrazines, respectively. The transformation of the Trichloromethyl Group under mild conditions into carboxylic Groups is also described.
Moisés Romero-ortega - One of the best experts on this subject based on the ideXlab platform.
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Reactivity of electrophilic chlorine atoms due to σ-holes: a mechanistic assessment of the chemical reduction of a Trichloromethyl Group by sulfur nucleophiles.
Physical chemistry chemical physics : PCCP, 2016Co-Authors: Guillermo Caballero-garcía, Moisés Romero-ortega, Joaquín Barroso-floresAbstract:σ-Holes are shown to promote the electrophilic behavior of chlorine atoms in a Trichloromethyl Group when bound to an electron-withdrawing moiety. A halogen bond-type non-covalent interaction between a chlorine atom and a negatively charged sulfur atom takes place, causing the abstraction of such a chlorine atom while leaving a carbanion, subsequently driving the chemical reduction of the Trichloromethyl Group to a sulfide in a stepwise process. The mechanism for the model reaction of Trichloromethyl pyrimidine 1 with thiophenolate and thiophenol to yield phenylsulfide 4 was followed through 1H-NMR and studied using DFT transition state calculations, and the energy profile for this transformation is fully discussed. MP2 calculations of the electrostatic potential were performed for a series of Trichloromethyl compounds in order to assess the presence of σ-holes and quantify them by means of the maximum surface electrostatic potential. Such calculations showed that the chlorine atoms behave as electrophilic leaving Groups toward a nucleophilic attack, opening a new possibility in the synthetic chemistry of the Trichloromethyl Group.
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A new synthesis of 2-substituted-1,3-dithianes from Trichloromethyl compounds
Tetrahedron Letters, 2007Co-Authors: Nancy González Rivera, David Corona Becerril, Carlos Guadarrama‐perez, Adrián Covarrubias-zúñiga, José Gustavo Ávila-zárraga, Moisés Romero-ortegaAbstract:Trichloromethyl compounds are efficiently converted into 1,3-dithianes upon reaction with a disodium 1,3-propanedithiolate-1,3-propanedithiol mixture in DMF solution at 0 °C. This synthesis is limited to those substrates where the substituent attached to the Trichloromethyl Group is an electron-withdrawing Group.
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Facile Synthesis of Thiolacetates from Trichloromethyl Compounds
Synthesis, 2003Co-Authors: Moisés Romero-ortega, Horacio Reyes, Adrian Covarruvias‐zuniga, Raymundo Cruz, José Gustavo Ávila-zárragaAbstract:A new method for the conversion of Trichloromethyl compounds into the corresponding thiolacetates by treatment with sodium thiolacetate in the presence of thiolacetic acid is described. This transformation proceeds at room temperature in high yield when a strong electron-withdrawing substituent is attached to the Trichloromethyl Group.
Anna V. Dolzhenko - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and biological activity of fluorinated 7-benzylamino-2-phenyl-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines
Journal of Fluorine Chemistry, 2015Co-Authors: Gigi N.c. Chiu, Bee Jen Tan, Wai Keung Chui, Anna V. DolzhenkoAbstract:Abstract New fluorinated 7-benzylamino-2-phenyl-1,2,4-triazolo[1,5- a ][1,3,5]triazin-5-amines were designed as potential anticancer agents and a practical method for their preparation was developed. The reaction of benzhydrazide with cyanoguanidine followed by intramolecular cyclocondensation resulted in the formation of triazolylguanidine, which upon condensation with trichloroacetonitrile afforded a key intermediate – 2-phenyl-7-Trichloromethyl-1,2,4-triazolo[1,5- a ][1,3,5]triazin-5-amine. In mild conditions, this intermediate underwent nucleophilic displacement of the Trichloromethyl Group with a series of fluorinated benzylamines providing the target compounds. Antiproliferative activity of the prepared compounds against the lung and breast cancer cells was explored. Together with anticancer effect, some compounds demonstrated anti-angiogenic properties.
