چكيده فارسي :
Pyrazole is amongst the most important structural units found in many different natural and
synthetic products that exhibit a wide range of biological activities [1]. Thepyrazole core is a
privileged heterocyclic scaffold, and is a constituent of agro-chemicals, and polymeric
materials, besides its use as a unique ligand. Although pyrazoles are rarely found in natural
products, they represent an important motif of man-made biologically active compounds such
as celecoxib, fipronil, lonazolac, viagra, and many others. In continuance of our interest in the
1,3-dipolar cycloaddition reactions [2,3] we describe our endeavor toward the synthesis of
1,3-diphenyl pyrazoles on the basis of the 1,3-dipolar cycloaddition protocol. Therefore a
straightforward, operationally simple and high yielding protocol for the synthesis of pyrazole
derivatives, from easily available starting materials is always needed. Presented in this article
are the results of One-Pot , three-component coupling of, 4-oxo-4H-chromene-3-
carbaldehyde, hydroxylamine hydrochloride and hydrazonoyl chlorides 1 to yield 1,3,4-
trisubstituted pyrazoles 2.We describe a straight forward strategy for the regioselective
synthesis of pyrazoles in good to excellent yields in EtOH as solvent at room temperature
(Figure 1).
