Green and Catalyst-free One-pot Synthesis Of 2,3-dihydroquinazolin-4(1h)-ones in Water

Unique and outstanding catalytic behavior of a novel MOF@COF composite as an emerging and powerful catalyst in the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives

The creation of an emerging porous structure using the hybridization of UiO-66-NH2-MOF, a zirconium-based metal-organic framework (MOF), with a covalent organic framework (COF) based on terephthaldehyde and melamine (UiO-66-NH2-MOF@COF), was assessed using SEM, XRD, EDX/mapping, FT-IR, BET, and TGA analyses. Using the obtained composite as a potential recoverable heterogeneous nanocatalyst, different aldehydes were condensed with isatoic anhydride and anilines or ammonium acetate under solvent-free conditions to create derivatives of 2,3-dihydroquinazolin-4(1H)-one. Examining the catalytic capabilities of the designed UiO-66-NH2-MOF@COF to efficiently produce 2,3-dihydroquinazolin-4(1H)-ones was a standout activity. Low catalyst loading, simple set-up, outstanding yields, and catalyst recoverability are all benefits of this research.

2,3-Dihydroquinazolin-4(1H)-one as a privileged scaffold in drug design

2,3-Dihydroquinazolin-4-one (DHQ) belongs to the class of nitrogen-containing heterocyclic compounds representing a core structural component in various biologically active compounds. In the past decades, several methodologies have been developed for the synthesis of the DHQ framework, especially the 2-substituted derivatives. Unfortunately, multistep syntheses, harsh reaction conditions, and the use of toxic reagents and solvents have limited their full potential as a versatile fragment. Recently, use of green chemistry and alternative strategies are being explored to prepare diverse DHQ derivatives. This fragment is used as a synthon for the preparation of biologically active quinazolinones and as a functional substrate for the synthesis of modified DHQ derivatives exhibiting different biological properties. In this review, we provide a comprehensive assessment of the synthesis and biological evaluations of DHQ derivatives.

Scalable preparation, characterization, and application of alkali-treated starch as a new organic base catalyst

Preparation, characterization, and application of alkali starch (AS) given by dry co-grinding of starch and alkali is described in this work. Grinding using a mortar (agate) and pestle or, more conveniently, a ball mill has been found to be satisfactory for the preparation of the AS. The AS products were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) and x-ray fluorescence (XRF) analyses. The base capacities of ASs were 4.25-4.45 mmol/g, respectively. AS is a low cost and easy to handle base catalyst that showed promising catalytic performance in the synthesis of a dihydroquinazoline-based antibacterial drug that involves tandem hydration or decarboxylative amidation, imination, and Aza-Michael reactions.

Novel Synthetic Approach for the Access of Functionalised 4H-Chromenes

A simple, efficient and high-yielding one-pot protocol for the synthesis of novel functionalised 4H-chromenes and chromene carboxylic acids has been developed using multi-component domino coupling reactions of anil-like compounds with 1,3-diketones and indole in the presence of formic acid catalyst under solvent-free conditions. The protocol avoids the use of expensive catalysts, toxic solvents and chromatographic separation.