By employing a catalytic proportion of Co-Al<sub>2</sub>O<sub>3</sub>-SO<sub>3</sub>H in a three-component Biginellitype condensation, combining various aromatic aldehydes, 1,3-cyclohexadione, and urea, practical one-pot synthesis of hexahydroquinazolinone was accomplished. This method yielded hexahydroquinazolinones in good yields, which were further enhanced under reflux conditions. This approach offers several significant advantages, including high efficiency, straightforward reaction conditions, simple workup, reusable catalysts, superior yields, and shorter reaction times. The structure of the produced heterogeneous catalyst Co-Al<sub>2</sub>O<sub>3</sub>-SO<sub>3</sub>H was analyzed using Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM).

Antioxidants are vital molecules that play a crucial role in maintaining optimal health by neutralizing reactive oxygen species (ROS) and mitigating oxidative stress, which is implicated in various chronic diseases, such as cancer and heart diseases. Apigenin, a naturally occurring flavonoid, has demonstrated significant antioxidant properties through free radical scavenging, metal ion chelation, and modulation of redox signaling pathways. We synthesized a series of novel apigenin derivatives via the Mannich reaction and evaluated their antioxidant activities using the 2,2-diphenyl-1- picrylhydrazyl (DPPH) assay. New derivatives of trihydroxychromen were synthesized and evaluated for their <i>in vitro</i> antioxidant activity. The target compounds were prepared by bonding pharmacophoric moieties possessing antioxidant activity, including amino substituents, via simple and efficient synthetic strategies. Physical and spectral data confirmed the structures of the newly synthesized compounds. The synthesized compounds 4e (IC50 = 0.09 μg/ml), 4i (IC50 = 2.74 μg/ml), and 4j (IC50 = 2.90 μg/ml) showed potential antioxidant activity than gallic acid (IC50 = 4.39 μg/ml) and exhibited moderate to excellent activities, with some derivatives surpassing the standard gallic acid. Molecular docking studies further elucidated the presence of an amino substituent at position 8 in compounds 4i, 4j, and 4e, resulting in good interactions with the receptor molecule's TYR662, ASN710, and GLN553. This study highlights the potential of apigenin derivatives as effective antioxidants with possible therapeutic applications.

Novel simple approach was elaborated for the preparation of fentanyl and sufentanil starting from commercially available, cheap 1-methyl-4-piperidone. Compared to existing syntheses new route is shorter, easily scalable, and does not require the use of expensive palladium catalysts, highpressure equipment, and chromatographic separations. Moreover, it allows for to avoidance of working with the unstable norsufentanil, which is prone to a facile acyl migration to the nitrogen atom of the piperidine core even at ambient temperature, resulting in contamination of the target product.

Understanding the rotational barriers (RBs) and bond dissociation enthalpies (BDEt) of substituted aromatic compounds is crucial for predicting their chemical reactivity and stability. The RBs for 26 varying para-substituted anilines, benzaldehydes, and toluenes around the respective phenyl- NH2, -CHO, and -CH3 bonds, as well as around the corresponding radical phenyl-NH, -CO, and - CH2 bonds, were computed, based on the Density Functional Theory (DFT). The BDEt of the aminic N-H, CO-H, and methyl C-H bonds in the respective neutral molecules was also computed. The RBs and various geometric, molecular, and atomic properties were used to explain how the substituents influence the BDEt. The trends were rationalized by considering the relative stabilization/destabilization of the parent neutral molecules versus the corresponding radicals. This study is the first in which trends in the RBs and BDEts are rationalized by considering the effect of substituent, providing valuable information for understanding the fundamental behavior of substituted aromatics.

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3, 3-di(indolyl)indolin-2-one derivatives have attracted the attention of researchers due to their various biological and medicinal applications. Due to the significant importance of indole compounds, various methods with different conditions and catalysts have been used for their synthesis. However, some of these reactions have disadvantages, such as low efficiency, long reaction time, use of toxic solvents, etc. In the study, iron nanocatalysts have been used as a suitable catalyst to prepare 3, 3-di(indolyl)indolin-2-one derivatives. This method has many advantages compared to other methods and it completes the reaction in a shorter time and with a higher yield, as described in this article.

result: M3MCn are liquid crystals that comprised phenyl rings as the core system, flexible alkyloxy chain at both terminal side and methyl substituents attached to the lateral position of the molecules. Observation under crossed polarized light reveals that all compounds are purely nematogens.

Herein, we disclose an eco-friendly route for the synthesis of 2,4,5-triaryl-1H-imidazole derivatives. One-pot, three-component synthesis involving benzil, substituted aromatic aldehydes, and ammonium acetate in the presence of a catalytic amount of trihexyltetradecyl-phosphonium bis(2,4,4-trimethylpentyl)phosphinate (PBIL) ionic liquid in ethanol at room temperature yields corresponding 2,4,5-triaryl-1H-imidazole derivatives in appreciable yield. The use of ionic liquid as a green catalyst with ethanol, which is considered to be an environmentally benign solvent, simple workup procedure, and appreciable yield of the product are some of the notable advantages of this method.

A novel and efficient method for synthesizing various quinoxaline derivatives has been developed, utilizing rainwater as both a solvent and a catalyst. This approach represents a significant advancement in green chemistry, as it combines simplicity, rapidity, and convenience while avoiding the need for toxic or expensive reagents. The synthesis involves the condensation reaction of aromatic 1,2-diamines with aromatic 1,2-dicarbonyl compounds. Traditionally, these reactions require specialized solvents and catalysts, but in this method, rainwater serves a dual function, streamlining the process and minimizing environmental impact. The use of rainwater not only simplifies the reaction setup but also provides an eco-friendly alternative to conventional organic solvents. The condensation leads to the formation of quinoxaline derivatives, a class of compounds known for their diverse biological and pharmacological activities. The reaction proceeds smoothly at ambient temperature, significantly reducing the energy requirements typically associated with chemical syntheses. This innovative synthesis method demonstrates the potential of using natural resources like rainwater in chemical reactions, contributing to sustainable practices in the field of organic synthesis. The versatility of the approach allows for the preparation of a variety of quinoxalines, offering promising applications in medicinal chemistry and material science. The rapid and straightforward process opens new avenues for the synthesis of quinoxalines, showcasing the potential of rainwater as a green solvent and catalyst in synthetic chemistry.