Ethylene glycol promoted catalyst-free pseudo three-component green synthesis of bis(coumarin)s and bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)s

An ethylene glycol promoted catalyst-free practically efficient and sustainable approach has been developed for the synthesis of several benzylidene-bis-(4-hydroxycoumarin)s and 4,4′\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$4^{\prime }$$\end{document}-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ol)s by the pseudo three-component reaction of an aldehyde with 4-hydroxycoumarin and 3-methyl-1-phenylpyrazol-5-one, respectively. Inexpensive, non-toxic, and easily available ethylene glycol used as the reaction solvent and promoter renders an efficient protocol in terms of catalyst-free reaction conditions, short reaction time, high yield, practical utility, and green approach.