1. High-Pressure Metal-Free Catalyzed One-Pot Two-Component Synthetic Approach for New 5-Arylazopyrazolo[3,4-b]Pyridine Derivatives
- Author
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Nayl, AbdElAziz A., Ibrahim, Hamada Mohamed, Dawood, Kamal M., Arafa, Wael A. A., Abd-Elhamid, Ahmed I., Ahmed, Ismail M., Abdelgawad, Mohamed A., Ali, Hazim M., Alsohaimi, Ibrahim Hotan, Aly, Ashraf A., Bräse, Stefan, and Mourad, Asmaa Kamal
- Subjects
5-amino-2-phenyl-4H-pyrazol-3-one ,Chemistry & allied sciences ,ddc:540 ,arylhydrazonals ,Q-tube ,5-arylazopyrazolo[3 ,4-b]pyridines - 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 NH$_4$OAc/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.
- Published
- 2022
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