TITLE:
An Eco-Friendly Synthesis of Heterocyclic Moieties Condensed with Pyrazole System under Green Conditions and Their Biological Activity
AUTHORS:
Mohamed A. El-Borai, Hala F. Rizk, Mohamed R. Sadek, Mai M. El-Keiy
KEYWORDS:
4-Bromo Pyrazolone, N-Bromo Saccharine, Chitosan, Microwave Irradiation, DPPH
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.6 No.2,
May
11,
2016
ABSTRACT: The efficient, facile and green synthesis of 4-bromo pyrazolone by using
N-bromo saccharine as valuable green reagent encouraged us to prepare some new
fused heterocycles as furopyrazole, pyranopyrazole, imidazopyrazole, pyrazolothiazole, pyrazol thiazolopyrimidine,
pyrazolothiazine, oxathinopyrazole,
pyrazolobenzooxazine, and pyrazoloquinoxaline. The synthesis
was carried out by a basic condensation of bromo pyrazolone 2 and a suitable
reagent in a one-pot reaction using chitosan as a green basic catalyst. The
reactions were carried out by microwave irradiation technique as a green source
of energy as well as the conventional heating. The antioxidant activity of the
prepared compounds was studied using 1,1-phenyl-2-picrylhydrazyl (DPPH) assay
and their antibacterial activity against Gram-positive, Gram-negative bacteria
and antifungal activity was evaluated.