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https://hdl.handle.net/1822/2199
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Campo DC | Valor | Idioma |
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dc.contributor.author | Carvalho, M. Alice | - |
dc.contributor.author | Zaki, M. | - |
dc.contributor.author | Proença, M. Fernanda R. P. | - |
dc.contributor.author | Booth, Brian L. | - |
dc.contributor.author | Álvares, Yolanda | - |
dc.date.accessioned | 2005-06-15T09:24:25Z | - |
dc.date.available | 2005-06-15T09:24:25Z | - |
dc.date.issued | 2004 | - |
dc.identifier.citation | "Organic and biomolecular chemistry". 2 (2004) 2340-2345. | eng |
dc.identifier.issn | 1477-0520 | por |
dc.identifier.uri | https://hdl.handle.net/1822/2199 | - |
dc.description.abstract | 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. | eng |
dc.description.sponsorship | Universidade do Minho. Fundação para a Ciência e Tecnologia - PRAXIS/C/QUI/10101/1998. | por |
dc.language.iso | eng | eng |
dc.publisher | Royal Society of Chemistry | eng |
dc.rights | openAccess | eng |
dc.subject | 6-enaminopurines | eng |
dc.subject | Imidazoles | eng |
dc.subject | Ethoxymethylenemalononitrile | eng |
dc.subject | Ethoxymethylenecyanoacetate | eng |
dc.subject | 6-methoxyformimidoyl purines | eng |
dc.subject | Malononitrile | eng |
dc.title | Synthesis of novel 6-enaminopurines | eng |
dc.type | article | eng |
dc.peerreviewed | yes | eng |
oaire.citationStartPage | 2340 | por |
oaire.citationEndPage | 2345 | por |
oaire.citationIssue | 16 | por |
oaire.citationVolume | 2 | por |
dc.identifier.doi | 10.1039/b406806h | por |
dc.identifier.pmid | 15305216 | por |
dc.subject.wos | Science & Technology | por |
sdum.journal | Organic and Biomolecular Chemistry | por |
Aparece nas coleções: | CDQuim - Artigos (Papers) |
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displayarticle.pdf | 439,85 kB | Adobe PDF | Ver/Abrir |