Current Organic Synthesis - Volume 22, Issue 2, 2025

The degree sequence of a graph is the list of its vertex degrees arranged in usually increasing order. Many properties of the graphs realized from a degree sequence can be deduced by means of a recently introduced graph invariant called omega invariant.

We used the definitions of the considered graph products together with the list of degree sequences of these graph products for some well-know graph classes. Naturally, the vertex degree and edge degree partitions are used. As the main theme of the paper is the omega invariant, we frequently used the definition and fundamental properties of this very new invariant for our calculations. Also, some algebraic properties of these products are deduced in line with some recent publications following the same fashion.

In this paper, we determine the degree sequences of strong and lexicographic products of two graphs and obtain the general form of the degree sequences of both products. We obtain a general formula for the omega invariant of strong and lexicographic products of two graphs. The algebraic structures of strong and lexicographic products are obtained. Moreover, we prove that strong and lexicographic products are not distributive over each other.

We have obtained the general expression for degree sequences of two important products of graphs and a general expression for omega invariants of strong and lexicographic products. Furthermore, we have obtained algebraic structures of strong and lexicographic products in terms of their degree sequences. Also, it has been found that the disruptive property does not hold for strong and lexicographic products.

The objective of this study is to compute the Kirchhoff index and resistance distance for two classes of windmill graphs, namely the French windmill graph and the Dutch windmill graph.

In this study, G is considered a simple connected graph with vertex set V (G) and edge set E (G). N is supposed to represent a network derived from G by substituting a 1-ohm resistor for each edge of G. In that case, the resistance between υ, ν ϵ V (G) is considered analogous to the resistance between two equivalent nodes in network N. We employed techniques from electrical network theory to compute the resistance distance and Kirchhoff index.

The Kirchhoff index of G is the sum of the resistance distances between all pairs of vertices in G. Our computations revealed specific patterns and relationships in the resistance distances and Kirchhoff indices across different classes of windmill graphs.

In addition, the Kirchhoff index and resistance distance are computed in this study for specific generalizations of these graphs. The derived equations can inspire further investigation into the resistance distance and Kirchhoff index in real-world windmill networks. Additionally, they offer a chemical framework for future research, aiding in the determination of molecular structures and characteristics.

In China, the traditional method for analyzing soil available phosphorus is inadequate for large-scale soil assessment and nationwide soil formulation demands. To address this, we propose a rapid and reliable method for soil-available phosphorus detection. The setup includes an on-site rapid pre-treatment device, a non-contact conductivity detection device, and a capillary electrophoresis buffer solution system composed of glacial acetic acid and hydroxypropyl-β-cyclodextrin.

The on-site rapid pre-treatment process includes fresh soil moisture content detection (moisture rapid detector), weighing (handheld weighing meter), stirring (handheld rapid stirrer), and filtration (soil rapid filter) to obtain the liquid sample, and direct injection (capillary electrophoresis detector). The phosphate ion detection parameters include capillary size, separation voltage, injection parameters, and electric injection. We used Liaoning brown soil, Henan yellow tidal soil, Heilongjiang black soil, and Anhui tidal soil as standard samples. Additionally, we used mathematical modeling methods and machine learning algorithms to analyze and process research data.

Following calibration with standard samples, the experimental blind test samples demonstrated conformity with the national standard method, exhibiting a relative standard deviation of less than 3%. The proposed pre-treatment device and non-contact conductivity detector are powered by lithium-ion batteries, rendering them ideal for extended field operations. The non-contact conductivity detector obviates the need for direct contact with test samples, mitigating environmental pollution. Furthermore, the neural network model exhibited the highest level of goodness of fit in chemical data analysis.

Nitroaromatic compounds are important scaffolds used for the synthesis of a variety of compounds, such as explosives, herbicides, dyes, perfumes and pharmaceuticals. Bismuth nitrate pentahydrate is a widely used reagent in organic synthesis; however, its utility as a nitrating agent for anilines is underexplored.

The aim of this work is to propose and find the proper reaction conditions of an alternative nitrating agent constituted by a mixture of bismuth nitrate / acetic anhydride in DCM with a series of substituted anilines under mild reflux.

Several anilines having both activating and deactivating substituents in the ortho, meta and para positions were the substrate for the nitration reaction. Experimental conditions were performed in “one-pot” conditions before product purification.

Bi(NO3)3•5H2O demonstrated to be effective and somehow regioselective when it came to the nitration of anilines in the ortho position. Although other products were also identified under these conditions, in most cases, the ortho derivative was the major or even the only product obtained with moderate to high yields in the range of 50% – 96%.

Bi(NO3)3•5H2O is an efficient and safe nitrating agent since the use of concentrated and corrosive acids like sulfuric and nitric is avoided; furthermore, bismuth nitrate is low-priced and no special care nor equipment is required.

One of the most researched issues is the elimination of uremic toxins from the human body. These toxins can build up and lead to catastrophic issues including renal failure. To get rid of them, absorbents like activated carbon, zeolites, and other minerals are frequently utilized.

Mesoporous silica nanoparticles functionalized with (3-Aminopropyl) triethoxysilane (APTES) linker (MSN-NH2) and mesoporous silica nanoparticles grafted with molecularly imprinted polymers (MSN-MIP) from the previous study were examined in this study to determine how well they absorbed urea, creatinine, and uric acid in a simulated intestinal serum.

MSN-MIP's large surface area (879.12 (m²/g)) and volume of pores (0.8475 (cm³/g)) made removal results that were satisfactory in the simulated serum. Additionally, MSN-MIP demonstrated a high urea adsorption capacity (qm = 1836.45 mg/g). Creatinine (qm = 1529.5 mg/g) and uric acid (qm = 1210.6 mg/g) were absorbed via NH-MSN2, which demonstrated a noticeable potential for absorption. The results of cell viability test for the first 72 hours, showed that the use of these absorbents in hemodialysis systems is acceptable.

Synthesized adsorbents can be utilized in the hemodialysis system since the results of the cell viability test also showed that the percentage of cell viability was extremely high up to 72 hours.

The small organic molecular compounds with biological activity containing C-C and C-N or C-O bonding were efficiently prepared without catalyst and solvent in the hydrothermal synthesis reactor.

Our goal was to explore new applications for the more environmentally friendly and efficient synthesis of bis(indolyl)methyl, xanthene, quinazolinone, and N-heterocyclic derivatives in hydrothermal synthesis reactors under solvent-free and catalyst-free conditions.

A greener and more efficient method was successfully developed for the synthesis of bis(indolyl)methyl, heteroanthracene, quinazolinone, and N-heterocyclic derivatives using a hydrothermal synthesis reactor in a solvent- and catalyst-free manner.

In a hydrothermal synthesis reactor, bis(indoyl)methyl, xanthene, quinazolinone, and N-heterocyclic derivatives were synthesized without catalysts and solvents.

Overall, it is proved once again that the catalyst-free and solvent-free synthesis method has universal value and is a more ideal and environmentally friendly new method, especially the hydrothermal reactor for synthesis.

The effect of power and duration of ultrasonic irradiation on the synthesis of thiazoles via the Hantzsch reaction was investigated.

The reaction of phenacyl bromides with thioamides under ultrasonic irradiation afforded the target thiazoles in good yields.

The results showed that high power and long irradiation time cause the decomposition of the reaction materials, and for this reaction, the irradiation power of 720 watts and a total duration of 4 minutes, wherein a pulsing function was performed in 50% of each second, were considered the most suitable irradiation properties for the synthesis of thiazoles through the Hantzsch reaction.

The use of mild conditions, short time frame, high yields, simple separation of the reaction product, and no use of the base for neutralization are the advantages of the present method.

A new series of 4-hydroxy-8-methyl-2-oxo-1,2-dihydroquinoline-3-carboxamide derivatives has been synthesized in good yields, followed by complete characterization using 1D-NMR, 2D-NMR, and IR techniques.

The final products contain amide, hydroxyl, and aromatic functional groups that usually show significant bioactivity. The target products have been examined towards three cancer cell lines, namely colorectal cancer cell line (HCT116), breast cancer cell line (MCF-7), and leukemia cell line (K562) in addition to the fibroblast cells, that were used as a model for normal human tissue.

The anticancer results signified that compound 6 showed the most activity in the series accomplished with IC50 values of 14.6, 5.3 and 12.8 M,

Other compounds exhibited considerable activity, such as compounds 9 (IC50 3.5 and 19.0 M), 10 (IC50 12.6 M), and 11 (IC50 10.3 M) against the three cancer cell lines HCT116, MCF-7 and K562, respectively.