Publication
Synthesis and structure elucidation of novel pyrazolyl-2-pyrazolines obtained by the reaction of 3-(3-aryl-3-oxopropenyl)chromen-4-ones with phenylhydrazine
| dc.contributor.author | Santos, Clementina M.M. | |
| dc.contributor.author | Silva, Artur | |
| dc.contributor.author | Jeko, József | |
| dc.contributor.author | Lévai, Albert | |
| dc.date.accessioned | 2013-03-15T16:09:00Z | |
| dc.date.available | 2013-03-15T16:09:00Z | |
| dc.date.issued | 2012 | |
| dc.description.abstract | 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. | por |
| dc.identifier.citation | 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 | por |
| dc.identifier.doi | 10.3998/ark.5550190.0013.522 | |
| dc.identifier.issn | 1551-7004 | |
| dc.identifier.uri | http://hdl.handle.net/10198/8272 | |
| dc.language.iso | eng | por |
| dc.peerreviewed | yes | por |
| dc.publisher | Arkat USA | |
| dc.subject | Chromones | por |
| dc.subject | Phenylhydrazine | por |
| dc.subject | Bispyrazoles | por |
| dc.subject | 4-Pyrazolyl-2-pyrazolines | por |
| dc.subject | Diastereomers | por |
| dc.subject | Planar chirality | por |
| dc.subject | NMR spectroscopy | por |
| dc.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 | por |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| oaire.citation.title | Arkivoc | por |
| person.familyName | Santos | |
| person.givenName | Clementina M.M. | |
| person.identifier.ciencia-id | 9018-DB9C-C590 | |
| person.identifier.orcid | 0000-0003-4380-7990 | |
| person.identifier.scopus-author-id | 7201458663 | |
| rcaap.rights | openAccess | por |
| rcaap.type | article | por |
| relation.isAuthorOfPublication | 64f662b6-775d-4ea0-bfd7-f527af0ac1a0 | |
| relation.isAuthorOfPublication.latestForDiscovery | 64f662b6-775d-4ea0-bfd7-f527af0ac1a0 |