[DDQM][HSO4]/TBHP as a Multifunctional Catalyst for the Metal Free Tandem Oxidative Synthesis of 2-Phenylquinazolin-4(3H)-ones

Gold nanoparticle-decorated amorphous carbon for oxidative cyclization of anthranilamide and aryl alcohols

Herein, gold nanoparticle-decorated amorphous carbon (Au/AC) was prepared by reducing chloroauric acid and layering it on amorphous carbon. The characteristics of Au/AC were examined using FT-IR, XRD, TGA, SEM, EDS, and XPS. To assess its catalytic activity, Au/AC was tested in a reaction involving anthranilamide and benzyl alcohol at 110 °C for 24 hours. This reaction yielded various 2-phenylquinazolin-4(3H)-one derivatives in moderate to good yields (44-80%). Furthermore, control experiments were conducted to demonstrate the oxidation and cyclization functions of Au/AC. Noteworthy aspects of this approach included the ease of isolating Au/AC (via recrystallization) and the ability to recycle it.

A vitamin C-based natural deep eutectic solvent for the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives

Efficient and green protocols were reported to synthesize 2,3-dihydroquinazolin-4(1H)-one derivatives in natural deep eutectic solvent (NADES). NADES was prepared from ascorbic acid (AA) and choline chloride (ChCl) with reduced or null toxicity, biocompatibility, and low cost. The ChCl/AA NADES was successfully used in the synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives via the condensation reaction of aldehydes with 2-aminobenzamide and the three-component reactions of aldehydes, isatoic anhydrides and ammonium salts under solvent-free conditions. The scope of this method was evaluated by employing various aromatic, heterocyclic, and aliphatic aldehydes. The desired products were achieved in 85-97 % yield in a short reaction time. Also, the deep eutectic solvent ChCl/AA showed good recyclability and reusability.

I2-Promoted Chemoselective Annulative Coupling of 2-Aminobenzamides with Sulfoxonium Ylides: Easy Access to Quinazolinones

A flexible and metal-free synthetic approach for synthesizing 2-benzoyl quinazolinones and 2-aryl quinazolinones via molecular iodine-mediated annulative coupling of sulfoxonium ylides with 2-aminobenzamides has been disclosed. The method demonstrates remarkable chemoselectivity and efficiency, leading to high yields of 2-benzoyl quinazolinones and 2-aryl quinazolinones under optimized conditions. The broad substrate scope, scalability, and practical utility were highlighted through diverse applications, including gram-scale reactions and the synthesis of biologically significant compounds such as tryptanthrin and the chemo/biosensor derivative.

Unveiling the Untapped Potential of Bertagnini's Salts in Microwave-Assisted Synthesis of Quinazolinones

Microwave-assisted organic synthesis (MAOS) has emerged as a transformative technique in organic chemistry, significantly enhancing the speed, efficiency, and selectivity of chemical reactions. In our research, we have employed microwave irradiation to expedite the synthesis of quinazolinones, using water as an eco-friendly solvent and thereby adhering to the principles of green chemistry. Notably, the purification of the product was achieved without the need for column chromatography, thus streamlining the process. A key innovation in our approach is using aldehyde bisulfite adducts (Bertagnini's salts) as solid surrogates of aldehydes. Bertagnini's salts offer several advantages over free aldehydes, including enhanced stability, easier purification, and improved reactivity. Green metrics and Eco-Scale score calculations confirmed the sustainability of this approach, indicating a reduction in waste generation and enhanced sustainability outcomes. This methodology facilitates the synthesis of a diverse array of compounds, offering substantial contributions to the field, with potential for widespread applications in pharmaceutical research and beyond.

H2O2-Mediated Synthesis of a Quinazolin-4(3H)-one Scaffold: A Sustainable Approach

A quinazolin-4(3H)-one ring system is a privileged heterocyclic moiety with distinctive biological properties. From this perspective, the development of an efficient strategy for the synthesis of quinazolin-4(3H)-one has always been in demand for the synthetic chemistry community. In this report, we envisaged an efficient protocol for the synthesis of quinazolin-4(3H)-one using substituted 2-amino benzamide with dimethyl sulfoxide (DMSO) as a carbon source and H2O2 as an effective oxidant. Mechanistically, the reaction proceeds through the radical approach with DMSO as one carbon source. To further substantiate the synthetic claim, the synthetic protocol has been extended to the synthesis of the anti-endotoxic active compound 3-(2-carboxyphenyl)-4-(3H)-quinazolinone.

Room temperature ligand-free Cu2O-H2O2 catalyzed tandem oxidative synthesis of quinazoline-4(3H)-one and quinazoline derivatives

An efficient and simple copper catalytic system has been developed for the synthesis of medicinally important 2-substituted quinazoline-4(3H)-ones from 2-aminobenzonitrile and benzyl alcohol derivatives and additionally 2-substituted quinazolines from 2-aminobenzylamine and benzaldehyde derivatives. Mild oxidant H₂O₂ was utilized, providing excellent product yields. The molecular structure of one of the compounds was substantiated through SC-XRD. The versatility of the protocol was demonstrated through gram-scale syntheses.

Cucurbit[6]uril supported β-Ni(OH)2 nanoparticles as a heterogeneous catalyst for the synthesis of quinazolines via acceptorless dehydrogenative coupling of alcohols with nitriles

Synthesis of a series of quinazolines using β-Ni(OH)2-CB[6] as a heterogeneous nanocatalyst.