Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/163391
Title: An Unequivocal Synthesis of 2-Aryl Substituted 3-Amino-2,4,5,7-tetrahydro-6H-pyrazolo[3,4-b]pyridin-6-ones
Author: Bou-Petit, Elisabeth
Picas, Elsa
Puigjaner Vallet, Ma. Cristina
Font Bardia, Ma. Mercedes
Ferrer,, N.
Sempere, J.
Puig de la Bellacasa, R.
Batllori, X.
Teixidó, Jordi
Estrada-Tejedor, R.
Ramon y Cajal, S.
Borrel, José I.
Keywords: Química orgànica
Compostos cíclics
Organic chemistry
Cyclic compounds
Issue Date: May-2017
Publisher: Wiley-VCH
Abstract: The reaction between pyridones (1) and substituted hydrazines 4 can afford two different regioisomeric pyrazolo[3,4-b]pyridin - 6-ones 2 and 3 depending on the initial substitution of the methoxy group and the direction of the cyclization. In the case of phenylhydrazine 4 (R3 = Ph), we have clearly shown that the treatment of pyridones 1a-d with 4 (R3 = Ph) in MeOH at temperatures below 1408C yields, independently of the nature and position of the substituents present in the pyridone ring, the open intermediates 7a-d. When the reaction is carried at 1408C under microwave irradiation, the corresponding 2-aryl substituted pyrazolo[3,4-b]pyridines 3a-d are always formed. We have experimentally determined, using DSC techniques, the activation energies of the two steps involved in the formation of 3: a) substitution of the methoxy group present in pyridones 1 with phenylhydrazine 4 (R3 = Ph) to afford intermediates 7 and b) cyclization of intermediates 7 to yield pyrazolopyridines 3. The results obtained, 15 and 42 kcal·mol 1 respectively, are in agreement with the experimental findings.
Note: Versió postprint del document publicat a: https://doi.org/10.1002/slct.201700732
It is part of: Chemistryselect, 2017, vol. 2, num. 13, p. 3668-3672
URI: http://hdl.handle.net/2445/163391
Related resource: https://doi.org/10.1002/slct.201700732
ISSN: 2365-6549
Appears in Collections:Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)

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