A choline hydroxide catalyzed synthesis of 2,3-dihydroquinazolin-4(1H)-ones in an aqueous medium

Abstract

A simple, metal and ligand-free protocol for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones derivatives using choline hydroxide (ChOH) as an effective catalyst in an aqueous medium has been developed. The good to high yield of the desired product is obtained, with low environmental factor and high atom economy. The ChOH was found to be recyclable up to six consecutive runs without significant loss in its activity. The use of water as an environmentally benign solvent, ease of work up and efficient recyclability of the catalyst makes this process more advantageous and greener.

Polyethylene Glycol‐Bonded Tetraethyl Ammonium Hydroxide ([PEG‐TEA]OH): A New Surfactant‐Combined Base Catalyst for the Synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones in Water

“…Based on obtained experimental results and literature reports, the selectivity of the synthesis of 2‐substituted‐2,3‐dihydroquinazolin‐4(1 H )‐ones ( 3 a‐ac ) in the presence of [PEG‐TEA]OH in water can be explained by the strict sequence of the reactions shown in Scheme . The process was initiated with the condensation reaction of carbonyl compounds ( 2 ) and 2‐aminobenzonitrile ( 1 ) to afford a Schiff base intermediate ( 8 ) in the presence of [PEG‐TEA]OH as a catalyst followed by a nucleophilic attack of counter hydroxide ion of [PEG‐TEA]OH on the electrophilic carbon of nitrile which convert the nitrile group to an amide moiety ( 9 ).…”

“…Other methods in this regard are the reaction of anthranilamide and 3,4‐dihydro‐2 H ‐pyran, the condensation of 2‐nitrobenzamide and aldehydes, the condensation of benzyl alcohols, amines and aldehydes and the reaction of gem‐dibromomethylarenes and anthranilamide . The newest synthetic pathway for the preparation of dihydroquinazolin‐4(1 H )‐ones is the reaction of 2‐aminobenzonitrile and aldehydes that was conducted in water using choline hydroxide as a reusable catalyst …”

“…[11] The newest synthetic pathway for the preparation of dihydroquinazolin-4(1H)-ones is the reaction of 2-aminobenzonitrile and aldehydes that was conducted in water using choline hydroxide as a reusable catalyst. [12] Growing awareness of the need for sustainable technologies has stimulated the chemistry community to streamline synthetic methodologies across academic and industrial fields. [13] The solvent and the reaction medium are two important factors in a sustainable synthetic pathway because in chemical reactions, solvents account for about 80% of the total mass handled.…”

β‐Cyclodextrin: A Green and Efficient Supramolecular Catalyst for Organic Transformations

“…A number of classical methods for synthesis of 2,3‐dihydroquinazolin‐4(1H)‐one have been reported in literature involving solid‐phase synthesis of 2‐arylamino substituted quinazolinones, reaction of ortho‐nitrobenzamide with aldehyde promoted by samarium iodide, reaction of anthranilamide with aldehydes or ketones in presence of cerium (IV) ammonium nitrate, silica sulfuric acid, ionic liquid/water, KAl(SO 4 ) 2 ⋅ 12H 2 O, gallium triflate, chiral phosphoric acid,, TiCl 4 −Zn in THF, amberlyst‐15 sulfonic acid, MCM−41−SO 3 H a mesoporous silica material, Sc(III)‐ inda ‐pybox, Choline hydroxide, ZnFe 2 O 4 , Yttrium nitrate, etc. However most of the reported methods involve the use of organic solvents, metal catalyst with tedious procedure and low yields of product.…”

Choline Hydroxide Promoted Synthesis of N‐Aryl Anthraquinone Derivatives: Metal Free Approach to Ullmann Coupling Reactions

“…Despite of these advantages, ionic liquids based on imidazolium and pyridinium salts, possess limitations such as toxicity, high cost and difficulty in preparation. Choline hydroxide (ChOH) is an environmentally benign, water soluble and biodegradable task‐specific ionic liquid which displays strong basicity . In our prior work we have reported C−N, C−O and C−S coupling reactions catalysed by deep eutectic solvents (DES) .…”