Synthesis of novel 6-enaminopurines
Autor(a) principal: | |
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Data de Publicação: | 2004 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/1822/2199 |
Resumo: | Two different approaches have been used for the synthesis of 6-enaminopurines 6 from 5-amino-4-cyanoformimidoyl imidazoles 1. In the first approach imidazoles 1 were reacted with ethoxymethylenemalononitrile or ethoxymethylenecyanoacetate under mild experimental conditions and this led to 9-substituted-6-(1-amino-2,2-dicyanovinyl) purines 6a-f or 9-substituted-6-(1-amino-2-cyano-2-methoxycarbonylvinyl) purines 6g-k. These reactions are postulated to occur through an imidazo-pyrrolidine intermediate 7, which rapidly rearranges to the 6-enaminopurine 6. In the second approach 6-methoxyformimidoyl purines 3, prepared in two efficient steps from 5-amino-4-cyanoformimidoyl imidazoles 1, were reacted with malononitrile and methylcyanoacetate with a mild acid catalysis (ammonium acetate or piperidinium acetate) to give 6-enaminopurines 6a, 6d, 6f, 6g and 6k in very good yields. Only low yields were obtained for the 6-enaminopurine 6j, as competing nucleophilic attack on C-8 of either 3d or 6j causes ring opening with formation of pyrimido-pyrimidines 11 and 10a respectively. |
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Synthesis of novel 6-enaminopurines6-enaminopurinesImidazolesEthoxymethylenemalononitrileEthoxymethylenecyanoacetate6-methoxyformimidoyl purinesMalononitrileScience & TechnologyTwo different approaches have been used for the synthesis of 6-enaminopurines 6 from 5-amino-4-cyanoformimidoyl imidazoles 1. In the first approach imidazoles 1 were reacted with ethoxymethylenemalononitrile or ethoxymethylenecyanoacetate under mild experimental conditions and this led to 9-substituted-6-(1-amino-2,2-dicyanovinyl) purines 6a-f or 9-substituted-6-(1-amino-2-cyano-2-methoxycarbonylvinyl) purines 6g-k. These reactions are postulated to occur through an imidazo-pyrrolidine intermediate 7, which rapidly rearranges to the 6-enaminopurine 6. In the second approach 6-methoxyformimidoyl purines 3, prepared in two efficient steps from 5-amino-4-cyanoformimidoyl imidazoles 1, were reacted with malononitrile and methylcyanoacetate with a mild acid catalysis (ammonium acetate or piperidinium acetate) to give 6-enaminopurines 6a, 6d, 6f, 6g and 6k in very good yields. Only low yields were obtained for the 6-enaminopurine 6j, as competing nucleophilic attack on C-8 of either 3d or 6j causes ring opening with formation of pyrimido-pyrimidines 11 and 10a respectively.Universidade do Minho. Fundação para a Ciência e Tecnologia - PRAXIS/C/QUI/10101/1998.Royal Society of ChemistryUniversidade do MinhoCarvalho, M. AliceZaki, M.Proença, M. Fernanda R. P.Booth, Brian L.Álvares, Yolanda20042004-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/1822/2199eng"Organic and biomolecular chemistry". 2 (2004) 2340-2345.1477-052010.1039/b406806h15305216info: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:RCAAP2023-07-21T12:31:34Zoai:repositorium.sdum.uminho.pt:1822/2199Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T19:26:49.457805Repositório 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 of novel 6-enaminopurines |
title |
Synthesis of novel 6-enaminopurines |
spellingShingle |
Synthesis of novel 6-enaminopurines Carvalho, M. Alice 6-enaminopurines Imidazoles Ethoxymethylenemalononitrile Ethoxymethylenecyanoacetate 6-methoxyformimidoyl purines Malononitrile Science & Technology |
title_short |
Synthesis of novel 6-enaminopurines |
title_full |
Synthesis of novel 6-enaminopurines |
title_fullStr |
Synthesis of novel 6-enaminopurines |
title_full_unstemmed |
Synthesis of novel 6-enaminopurines |
title_sort |
Synthesis of novel 6-enaminopurines |
author |
Carvalho, M. Alice |
author_facet |
Carvalho, M. Alice Zaki, M. Proença, M. Fernanda R. P. Booth, Brian L. Álvares, Yolanda |
author_role |
author |
author2 |
Zaki, M. Proença, M. Fernanda R. P. Booth, Brian L. Álvares, Yolanda |
author2_role |
author author author author |
dc.contributor.none.fl_str_mv |
Universidade do Minho |
dc.contributor.author.fl_str_mv |
Carvalho, M. Alice Zaki, M. Proença, M. Fernanda R. P. Booth, Brian L. Álvares, Yolanda |
dc.subject.por.fl_str_mv |
6-enaminopurines Imidazoles Ethoxymethylenemalononitrile Ethoxymethylenecyanoacetate 6-methoxyformimidoyl purines Malononitrile Science & Technology |
topic |
6-enaminopurines Imidazoles Ethoxymethylenemalononitrile Ethoxymethylenecyanoacetate 6-methoxyformimidoyl purines Malononitrile Science & Technology |
description |
Two different approaches have been used for the synthesis of 6-enaminopurines 6 from 5-amino-4-cyanoformimidoyl imidazoles 1. In the first approach imidazoles 1 were reacted with ethoxymethylenemalononitrile or ethoxymethylenecyanoacetate under mild experimental conditions and this led to 9-substituted-6-(1-amino-2,2-dicyanovinyl) purines 6a-f or 9-substituted-6-(1-amino-2-cyano-2-methoxycarbonylvinyl) purines 6g-k. These reactions are postulated to occur through an imidazo-pyrrolidine intermediate 7, which rapidly rearranges to the 6-enaminopurine 6. In the second approach 6-methoxyformimidoyl purines 3, prepared in two efficient steps from 5-amino-4-cyanoformimidoyl imidazoles 1, were reacted with malononitrile and methylcyanoacetate with a mild acid catalysis (ammonium acetate or piperidinium acetate) to give 6-enaminopurines 6a, 6d, 6f, 6g and 6k in very good yields. Only low yields were obtained for the 6-enaminopurine 6j, as competing nucleophilic attack on C-8 of either 3d or 6j causes ring opening with formation of pyrimido-pyrimidines 11 and 10a respectively. |
publishDate |
2004 |
dc.date.none.fl_str_mv |
2004 2004-01-01T00:00:00Z |
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/1822/2199 |
url |
http://hdl.handle.net/1822/2199 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
"Organic and biomolecular chemistry". 2 (2004) 2340-2345. 1477-0520 10.1039/b406806h 15305216 |
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 |
Royal Society of Chemistry |
publisher.none.fl_str_mv |
Royal Society of Chemistry |
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 |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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1799132756775534592 |