One-pot three-component synthesis of dialkyl 3-(alkylamino)-1-aryl-1H-pyrazole-4,5-dicarboxylates using α-Fe2O3 nanoparticles and phenylisocyanate in solvent-free conditions

This work described a simple and efficient synthesis of dialkyl 3-(alkylamino)-1-aryl-1H-pyrazole-4,5-dicarboxylates via a three component reaction between arylhydrazine, alkylisocyanid and dialkylacetylenedicarboxylates in the presence of phenylisocyanate and α-Fe2O3 nanoparticles. Eco friendly, solvent-free conditions, excellent yields, and short reaction times, inexpensive and readily available catalysts are the main advantages of this method. In this work, phenylisocyanate and α-Fe2O3 nanoparticles used as a potent mixed catalyst for promoting the reaction and taking it in a special way to obtain the titled compounds in good to excellent yields. This reaction was not carried out without any of the components of this mixed catalyst. It means that for performance this reaction both of the mixed catalyst components is required.