Graphite decorated nano alumina (nano Al2O3@Cg): A versatile inorganic nano-promoter for the synthesis of 4-alkyl-5-methyl-1H-pyrazol-3-ols in aqueous media

A benign, simple, and efficient synthesis of 4-alkyl-5-methyl-1H-pyrazol-3-ols has been described in refluxing water through the four-component reaction of beta-ketoesters, hydrazine hydrate, different aldehydes, and acetophenone derivatives in the presence of nano Al2O3@Cg, as a novel nanocatalyst. The new promoter has been prepared via a straightforward procedure and characterized by fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDAX), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) techniques. Utilizing water as the reaction medium, uncomplicated operational procedure, mild reaction conditions, application of a cost-effective, nontoxic, heterogeneous, easily available nanoscale inorganic-based catalyst, wide-range of substrates usage, and recovery and reusability of nano Al2O3@Cg catalyst within 4 runs without activity loss, are some highlighted features of the reported method. (C) 2018 Published by Elsevier Ltd.