Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine

Detalhes bibliográficos
Autor(a) principal: Santos, Clementina M.M.
Data de Publicação: 2012
Outros Autores: Silva, Artur, Jeko, József, Lévai, Albert
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10198/8272
Resumo: Novel 3-aryl-5-{4-[5-(2-hydroxyphenyl)-1-phenylpyrazolyl]}-2-pyrazolines 2a-g have been prepared by the treatment of 3-(3-aryl-3-oxopropenyl)chromen-4-ones 1a-g with phenylhydrazine in refluxing acetic acid. NMR studies on deuteriochloroform solutions of pyrazolyl-2-pyrazolines 2a-g at different temperatures showed that at room temperature a mixture of diastereomers are present. This diastereoselectivity arises from the combination of the pyrazoline C-4 stereocenter and two planar chiral subunits due to internal steric hindrance. The energy barriers of this steric hindrance were overcome in DMSO-d6 solutions at 60oC. The acetylation of some pyrazolyl-2-pyrazoline derivativess 2a-c,e helped to confirm the presence of the referred mixture of diastereomers.
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spelling Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazineChromonesPhenylhydrazineBispyrazoles4-Pyrazolyl-2-pyrazolinesDiastereomersPlanar chiralityNMR spectroscopyNovel 3-aryl-5-{4-[5-(2-hydroxyphenyl)-1-phenylpyrazolyl]}-2-pyrazolines 2a-g have been prepared by the treatment of 3-(3-aryl-3-oxopropenyl)chromen-4-ones 1a-g with phenylhydrazine in refluxing acetic acid. NMR studies on deuteriochloroform solutions of pyrazolyl-2-pyrazolines 2a-g at different temperatures showed that at room temperature a mixture of diastereomers are present. This diastereoselectivity arises from the combination of the pyrazoline C-4 stereocenter and two planar chiral subunits due to internal steric hindrance. The energy barriers of this steric hindrance were overcome in DMSO-d6 solutions at 60oC. The acetylation of some pyrazolyl-2-pyrazoline derivativess 2a-c,e helped to confirm the presence of the referred mixture of diastereomers.Arkat USABiblioteca Digital do IPBSantos, Clementina M.M.Silva, ArturJeko, JózsefLévai, Albert2013-03-15T16:09:00Z20122012-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10198/8272engSantos, Clementina M. M.; Silva, Artur; Jeko, J.; Levai, A. (2012). Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine. ARKIVOC. ISSN 1551-7004. 5, p. 265-2811551-700410.3998/ark.5550190.0013.522info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-21T10:19:38Zoai:bibliotecadigital.ipb.pt:10198/8272Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T22:59:37.716814Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
title Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
spellingShingle Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
Santos, Clementina M.M.
Chromones
Phenylhydrazine
Bispyrazoles
4-Pyrazolyl-2-pyrazolines
Diastereomers
Planar chirality
NMR spectroscopy
title_short Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
title_full Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
title_fullStr Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
title_full_unstemmed Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
title_sort Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
author Santos, Clementina M.M.
author_facet Santos, Clementina M.M.
Silva, Artur
Jeko, József
Lévai, Albert
author_role author
author2 Silva, Artur
Jeko, József
Lévai, Albert
author2_role author
author
author
dc.contributor.none.fl_str_mv Biblioteca Digital do IPB
dc.contributor.author.fl_str_mv Santos, Clementina M.M.
Silva, Artur
Jeko, József
Lévai, Albert
dc.subject.por.fl_str_mv Chromones
Phenylhydrazine
Bispyrazoles
4-Pyrazolyl-2-pyrazolines
Diastereomers
Planar chirality
NMR spectroscopy
topic Chromones
Phenylhydrazine
Bispyrazoles
4-Pyrazolyl-2-pyrazolines
Diastereomers
Planar chirality
NMR spectroscopy
description Novel 3-aryl-5-{4-[5-(2-hydroxyphenyl)-1-phenylpyrazolyl]}-2-pyrazolines 2a-g have been prepared by the treatment of 3-(3-aryl-3-oxopropenyl)chromen-4-ones 1a-g with phenylhydrazine in refluxing acetic acid. NMR studies on deuteriochloroform solutions of pyrazolyl-2-pyrazolines 2a-g at different temperatures showed that at room temperature a mixture of diastereomers are present. This diastereoselectivity arises from the combination of the pyrazoline C-4 stereocenter and two planar chiral subunits due to internal steric hindrance. The energy barriers of this steric hindrance were overcome in DMSO-d6 solutions at 60oC. The acetylation of some pyrazolyl-2-pyrazoline derivativess 2a-c,e helped to confirm the presence of the referred mixture of diastereomers.
publishDate 2012
dc.date.none.fl_str_mv 2012
2012-01-01T00:00:00Z
2013-03-15T16:09:00Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10198/8272
url http://hdl.handle.net/10198/8272
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Santos, Clementina M. M.; Silva, Artur; Jeko, J.; Levai, A. (2012). Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine. ARKIVOC. ISSN 1551-7004. 5, p. 265-281
1551-7004
10.3998/ark.5550190.0013.522
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Arkat USA
publisher.none.fl_str_mv Arkat USA
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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