Combined XRD and DFT studies towards understanding the impact of intramolecular H-bonding on the reductive cyclization process in pyrazole derivatives

Paweł Szlachcic , Tomasz Uchacz , Marlena Gryl , Andrzej Danel , Katarzyna Wojtasik , Przemysław Kołek , Bożena Jarosz , Katarzyna M. Stadnicka


The manuscript comprises the analysis of pyrazole derivatives: (5-methyl-4-nitro-2-phenyl-2H-pyrazol-3-yl)-phenyl-amines and (2H-pyrazol-3-yl)-(2-nitrophenyl)-amines molecular structure as obtained for from single-crystal X-ray diffraction measurements and DFT calculations. High temperature requirements for the reductive cyclization of the derivatives, leading to substituted 1H-pyrazolo[3,4-b]quinoxalines were discussed and explained. Our results show that one of the important factors responsible for low reactivity of the studied compounds is the existence of intramolecular hydrogen bonds. Alternative conditions for the synthesis involving microwave irradiation were proposed and tested within the study.
Author Paweł Szlachcic (FoFT / IoCh)
Paweł Szlachcic,,
- Institute of chemistry
, Tomasz Uchacz
Tomasz Uchacz,,
, Marlena Gryl
Marlena Gryl,,
, Andrzej Danel (FoFT / IoCh)
Andrzej Danel,,
- Institute of chemistry
, Katarzyna Wojtasik (FoFT / IoCh)
Katarzyna Wojtasik,,
- Institute of chemistry
, Przemysław Kołek
Przemysław Kołek,,
, Bożena Jarosz (FoFT / IoCh)
Bożena Jarosz,,
- Institute of chemistry
, Katarzyna M. Stadnicka
Katarzyna M. Stadnicka,,
Journal seriesJournal of Molecular Structure, ISSN 0022-2860, e-ISSN 1872-8014, (N/A 70 pkt)
Issue year2020
Publication size in sheets0.5
Article number127087
Keywords in English1H-pyrazolo[3,4-b]quinoxalines, DFT calculations, X-ray diffraction, Energy barrier, Hydrogen bond energy
ASJC Classification1602 Analytical Chemistry; 1604 Inorganic Chemistry; 1605 Organic Chemistry; 1607 Spectroscopy
Languageen angielski
Score (nominal)70
Score sourcejournalList
Publication indicators WoS Citations = 0; Scopus SNIP (Source Normalised Impact per Paper): 2018 = 0.807; WoS Impact Factor: 2018 = 2.12 (2) - 2018=1.861 (5)
Citation count*
Additional fields
FinansowanieThe part of the research was carried out with the equipment purchased thanks to the financial support of the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program (contract no. POIG.02.01.00-12-023/08). Chemicals for the purpose of the research were financed by the Ministry of Science and Higher Education of the Republic of Poland (DS 3711/3/ICh).
Share Share

Get link to the record

* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.
Are you sure?