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Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/61937
Title: Hydrogen-bond-mediated self-assembly of 26-membered diaza tetraester crowns of 3,5-disubstituted 1 h -pyrazole. Dimerization study in the solid state and in CDCl3 solution
Authors: Reviriego, Felipe; Navarro, Pilar; Arán, Vicente J.; Jimeno, M. Luisa; García-España, Enrique; Latorre, Julio; Yunta, María J. R.
Issue Date: 2011
Publisher: American Chemical Society
Citation: Journal of Organic Chemistry 76: 8223- 8231 (2011)
Abstract: By using an improved synthetic method reported earlier, the cyclic stannoxanes obtained from RN-diethanolamine (R = Me, Bu) and dibutyltin oxide have been reacted with 1H-pyrazole-3,5-dicarbonyl dichloride to afford 26-membered diaza tetraester crowns (1, R = Me; 3, R = Bu) and 39-membered triaza hexaester crowns (2, R = Me; 4, R = Bu). The new structures were identified from their analytical and spectroscopic (1H and 13C NMR, FAB-MS, and/or ESI-MS) data. Both diaza tetraester crowns (1 and 3), containing two 1H-pyrazole units, self-assemble into dimeric species through the formation of four hydrogen bonds involving the two NH pyrazole groups and the two tertiary amine groups of both crowns, as proved by X-ray crystallography and NMR analysis. Preliminary NMR, ESI-MS, MALDI-TOF-MS, and molecular modeling studies suggest that, in CDCl3 solution, 1 interacts with ethyleneurea (ETU), affording 1:1, 2:1, and 2:2 1-ETU complexes. © 2011 American Chemical Society.
URI: http://hdl.handle.net/10261/61937
Identifiers: doi: 10.1021/jo2012835
issn: 0022-3263
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