High-Pressure Metal-Free Catalyzed One-Pot Two-Component Synthetic Approach for New 5-Arylazopyrazolo[3,4- b]Pyridine Derivatives

AbdElAziz A Nayl; Hamada Mohamed Ibrahim; Kamal M Dawood; Wael A A Arafa; Ahmed I Abd-Elhamid; Ismail M Ahmed; Mohamed A Abdelgawad; Hazim M Ali; Ibrahim Hotan Alsohaimi; Ashraf A Aly; Stefan Bräse; Asmaa Kamal Mourad

doi:10.3390/molecules27196369

High-Pressure Metal-Free Catalyzed One-Pot Two-Component Synthetic Approach for New 5-Arylazopyrazolo[3,4- b]Pyridine Derivatives

Molecules. 2022 Sep 27;27(19):6369. doi: 10.3390/molecules27196369.

Affiliations

¹ Department of Chemistry, College of Science, Jouf University, Sakaka 72341, Al Jouf, Saudi Arabia.
² Chemistry Department, Faculty of Science, Fayoum University, Fayoum 63514, Faiyum, Egypt.
³ Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Giza, Egypt.
⁴ Composites and Nanostructured Materials Research Department, Advanced Technology and New Materials Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg Al-Arab 21934, Alexandria, Egypt.
⁵ Department of Pharmaceutical Chemistry, College of Pharmacy, Jouf University, Sakaka 72341, Al Jouf, Saudi Arabia.
⁶ Chemistry Department, Faculty of Science, Organic Division, Minia University, El-Minia 61519, Menia, Egypt.
⁷ Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76133 Karlsruhe, Germany.
⁸ Institute of Biological and Chemical Systems-Functional Molecular Systems (IBCS-FMS), Director Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.

Abstract

An appropriate and efficient Q-tube-assisted ammonium acetate-mediated protocol for the assembly of the hitherto unreported 5-arylazopyrazolo[3,4-b]pyridines was demonstrated. This methodology comprises the cyclocondensation reaction of 5-amino-2-phenyl-4H-pyrazol-3-one with an assortment of arylhydrazonals in an NH₄OAc/AcOH buffer solution operating a Q-tube reactor. This versatile protocol exhibited several outstanding merits: easy work-up, mild conditions, scalability, broad substrate scope, safety (the Q-tube kit is simply for pressing and sealing), and a high atom economy. Consequently, performing such reactions under elevated pressures and utilizing the Q-tube reactor seemed preferable for achieving the required products in comparison to the conventional conditions. Diverse spectroscopic methods and X-ray single-crystal techniques were applied to confirm the proposed structure of the targeted compounds.

Keywords: 5-amino-2-phenyl-4H-pyrazol-3-one; 5-arylazopyrazolo[3,4-b]pyridines; Q-tube; arylhydrazonals.

MeSH terms

Catalysis
Chemistry Techniques, Synthetic
Pyridines* / chemistry

Substances

Pyridines

Grants and funding

This work was funded by the Deanship of Scientific Research at Jouf University under grand No. (DSR2022-RG-0130)./Al Jouf University