Alternative and efficient one-pot three-component synthesis of substituted 2-aryl-4-styrylquinazolines/4-styrylquinazolines from synthetically available 1-(2-aminophenyl)-3-arylprop-2-en-1-ones: characterization and evaluation of their antiproliferative activities

In this study, an alternative and efficient one-pot three-component synthesis approach to develop a new series of (E)-2-aryl-4-styrylquinazolines and (E)-4-styrylquinazolines is described. According to this approach, the target compounds were synthesized straightforward in high yields and in short reaction times from substituted 1-(2-aminophenyl)-3-arylprop-2-en-1-ones via its well-Cu(OAc)2-mediated cyclocondensation reactions with aromatic aldehydes or its well-catalyst-free cyclocondensation reactions with trimethoxy methane (trimethyl orthoformate), and ammonium acetate under aerobic conditions. This is an operationally simple, valuable, and direct method to synthesize 2-aryl- and non-C2-substituted quinazolines containing a styryl framework at C4 position from cheap and synthetically available starting materials. All the synthesized compounds were submitted to the US National Cancer Institute for in vitro screening. The bromo- and chloro-substituted quinazolines 5c and 5d displayed a potent antitumor activity against all the tested subpanel tumor cell lines with IC50 (MG-MID) values of 5.25 and 5.50 μM, and a low cytotoxic effect with LC50 (MG-MID) values of 91.20 and 84.67 μM, respectively, indicating a low toxicity of these compounds to normal human cell lines, as required for potential antitumor agents.

Recent Advances in Metal-Catalyzed Approaches for the Synthesis of Quinazoline Derivatives

Quinazolines are an important class of heterocyclic compounds that have proven their significance, especially in the field of organic synthesis and medicinal chemistry because of their wide range of biological and pharmacological properties. Thus, numerous synthetic methods have been developed for the synthesis of quinazolines and their derivatives. This review article briefly outlines the new synthetic methods for compounds containing the quinazoline scaffold employing transition metal-catalyzed reactions.

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.

Transition-metal-catalyzed synthesis of quinazolines: A review

Quinazolines are a class of nitrogen-containing heterocyclic compounds with broad-spectrum of pharmacological activities. Transition-metal-catalyzed reactions have emerged as reliable and indispensable tools for the synthesis of pharmaceuticals. These reactions provide new entries into pharmaceutical ingredients of continuously increasing complexity, and catalysis with these metals has streamlined the synthesis of several marketed drugs. The last few decades have witnessed a tremendous outburst of transition-metal-catalyzed reactions for the construction of quinazoline scaffolds. In this review, the progress achieved in the synthesis of quinazolines under transition metal-catalyzed conditions are summarized and reports from 2010 to date are covered. This is presented along with the mechanistic insights of each representative methodology. The advantages, limitations, and future perspectives of synthesis of quinazolines through such reactions are also discussed.

I2/CuCl2-Copromoted Formal [4 + 1 + 1] Cyclization of Methyl Ketones, 2-Aminobenzonitriles, and Ammonium Acetate: Direct Access to 2-Acyl-4-aminoquinazolines

We herein report an I₂/CuCl₂-copromoted diamination of C(sp³)-H bonds for the preparation of 2-acyl-4-aminoquinazolines from methyl ketones, 2-aminobenzonitriles, and ammonium acetate. This reaction features operational simplicity, commercially available substrates, mild reaction conditions, and good functional group compatibility. Mechanistic studies indicate that CuCl₂ plays a pivotal role in this transformation. This study uses a methyl group as a novel input to construct 2-acyl-4-aminoquinazoline derivatives for the first time.

Palladium-Catalyzed Methylsulfonylation of Alkyl Halides Using Dimethyl Sulfite as SO2 Surrogate and Methyl Source

A novel and efficient method for the synthesis of methyl sulfone derivatives via palladium-catalyzed methylsulfonylation of alkyl halides with dimethyl sulfite has been described. A variety of aryl and alkyl iodides underwent the sulfonylation smoothly to furnish methyl sulfites in moderate to excellent yields.

Liquid Chromatography Analysis of Reactive Oxoammonium Cations

This study presents the first liquid chromatography method for the quantitative and qualitative analysis of highly reactive oxoammonium cations based on a simple derivatization reaction. Rapid 1,2-electrophilic addition reactions with olefins were used to transform these reactive species into analyzable derivates. Three model substances were chosen to represent each of the main application fields of oxoammonium cations and to demonstrate the versatility of the method. The measuring protocol was validated according to the ICH and USP guidelines. The method revealed an excellent linearity (R2 = 0.9980–0.9990) with a low limit of detection (0.16–0.14 mmol L−1) and a low limit of quantification (0.55–0.43 mmol L−1). The protocol was finally used to determine the oxoammonium cations in the presence of their corresponding radical, showing a robustness against impurity concentration of up to approx. 30%.

Electrosynthesis of Quinazolines and Quinazolinones via an Anodic Direct Oxidation C(sp3)-H Amination/C-N Cleavage of Tertiary Amine in Aqueous Medium

An electrochemical synthesis for quinazolines and quinazolinones was developed via a C(sp³)-H amination/C-N cleavage by virtue of the anodic oxidation. The reaction can be carried out in aqueous media under mild conditions to afford the desired products with high yields. The reaction mechanism was proposed after detailed investigation.

TFA-Mediated DMSO-Participant Sequential Oxidation/1,3-Dipolar Cycloaddition Cascade of Pyridinium Ylides for the Assembly of Indolizines

A trifluoroacetic acid (TFA)-mediated cascade oxidation/1,3-dipolar cycloaddition reaction of stabilized pyridinium salts with dimethyl sulfoxide (DMSO) has been developed in the presence of K2S2O8 and trimethylethylenediamine (TMEDA). In this transition-metal-free reaction, DMSO acts as a one-carbon source, thus providing a convenient method for the efficient and direct synthesis of various indolizine derivatives.

Copper-catalyzed oxidative amination of methanol to access quinazolines

A novel method for the copper-catalyzed oxidative amination of 2′-aminoarylketones with methanol as a C1 carbon source and ammonium acetate as an amine source to construct quinazolines was established in a one-pot manner.

A cascade oxidation/[4 + 1] annulation of sulfonium salts for synthesis of polyfunctional furans: DMSO as one carbon source

A novel DMSO-involved cascade reaction of stabilized sulfonium salts has been established for direct construction of polyfunctional furans.

Concise Xanthine Synthesis through a Double-Amidination Reaction of a 6-Chlorouracil with Amidines using Base-Metal Catalysis

A new and concise route towards xanthines through a double-amidination reaction is described; consecutive intermolecular C-Cl and intramolecular oxidative C-H amidination. N-uracil amidines are obtained through S_N AE on a 6-chlorouracil with amidines. Direct Cu-catalyzed oxidative C-H amidination on these N-uracil amidines yields polysubstituted xanthines. Sustainable oxidants, tBu₂ O₂ or O₂ , can be used in this oxidase-type reaction. The protocol allows for the introduction of N1, N3, N7, and C8 substituents during the xanthine-scaffold construction, thus avoiding post-functionalization steps. Both 6-chlorouracils and amidines are readily available commercially or through synthesis.

Acid-promoted oxidative methylenation of 1,3-dicarbonyl compounds with DMSO: application to the three-component synthesis of Hantzsch-type pyridines

A series of polysubstituted pyridines and methylene-bridged bis-1,3-dicarbonyl compounds were prepared in high yields from 1,3-dicarbonyl compounds and DMSO, wherein DMSO serves as solvent, carbon source, and oxidant.

Carbon annulation of ortho-vinylanilines with dimethyl sulfoxide to access 4-aryl quinolines

A palladium-catalyzed annulation of ortho-vinylanilines with dimethyl sulfoxide was developed to access 4-aryl quinolines in moderate to good yields.