Pd(0)‐guanidine@MCM‐41: a very effective catalyst for rapid production of bis (pyrazolyl)methanes

Abstract

In this research, a rapid, green and efficient protocol for synthesis of bis (pyrazolyl)methane derivatives in the presence of Pd(0)‐guanidine@MCM‐41 catalysts under solvent‐free conditions by the following two methods has been reported: (i) via the one‐pot pseudo five‐component reaction among phenylhydrazine (2 equivalents), ethyl acetoacetate (2 equivalents) and aromatic aldehydes (1 equivalent); and (ii) the one‐pot pseudo three‐component reaction between 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐one (2 equivalents) and aromatic aldehydes (1 equivalent). Some advantages of this protocol include: green conditions, extremely short times, high efficiency, proper one‐pot operation, generality of method, easy work‐up and recyclability, and reusability of the catalyst up to five times without significant loss in catalytic activity.