Background: Multicomponent reactions (MCRs) are one of the most revolutionary concepts
in synthetic organic chemistry. By definition, an MCR is a convergent chemical process involving
three or more reactants to fabricate products which retain all structural and substructural features of the
starting materials. The value of MCRs lies in all areas of synthetic chemistry, as they offer shorter reaction
time, uncomplicated process protocol and high yield. We here reported a novel, effortless, ecofriendly
multi-component one-pot synthesis of potent 2,3-dihydroquinazoline-4(1H)-ones is disclosed.
Methods: The method causes condensation of isatoic anhydride, ammonium salts and aromatic aldehydes
in ethanol. The reaction further employs metal chloride catalyst and offers significant advantages
including the use of green solvent and unsophisticated work-up methodology. Additionally,
the method is of value owing to the excellent yield obtained by the reaction.
Results: The multicomponent reaction of isatoic anhydride and ammonium chloride with various aldehydes
was investigated in presence of ethanol at reflux for 1.5 h. The catalytic MCR of a substituted
aldehyde with ammonium chloride and isatoic anhydride generates 10 products with percentage yield
ranging from 84-95%.
Conclusion: In a nutshell, it can be stated that indium chloride-catalyzed multi-component reaction is
a novel and efficient method for the synthesis of 2,3-dihydroquinazoline-4(1H)-ones. Significant advantages
of the method include the use of simple and readily available precursors, high yield and easy
workup with short reaction times. Better reactivity of ammonium chloride and high catalytic activity
of InCl3 is an added advantage while using ethanol as a green solvent renders the reaction an ecocompatible