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

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

Keywords:

Pyrazole , α-Fe2O3 , phenylisocyanate , nanocatalyst , solvent-free