Letters in Organic Chemistry - Volume 20, Issue 7, 2023

A series of pyranopyrazoles were synthesized via a one-pot four-component approach. The reaction was catalyzed by a β-CD/Yb(OTf)3 dual catalytic system. The protocol demonstrated offers several advantages such as short reaction times, excellent yields, good functional group tolerance, ambient and environmentally benign conditions, scalability and simple purification. Such dual catalytic systems are an attractive alternative to regular catalysts and can be further explored for a diverse set of reactions.

A rapid and facile one-pot three-component synthesis of biologically active 6-amino-5- cyano-4-aryl-1,4-dihydro pyrano[2,3-c] pyrazoles was developed using chitosan-p-toluene sulfonate (CS-p-TSA) as a biodegradable catalyst in an aqueous medium. The products synthesized were characterized by FT-IR, 1H-NMR, and 13C NMR. The catalyst was stable and could be used for five cycles without much change in the catalytic activity. The products synthesized were in good yields (90-96%). This method provides several advantages, including the use of a biodegradable catalyst, a simple workup procedure, mild reaction conditions, and lower reaction times.

A series of N-(furan/thiophene/pyrrole-2-yl-(2-hydroxynaphthalen-1-yl)methyl) acetamide derivatives 4 has been depicted by one-pot three-component synthesis using 2- naphthol 1 with aldehydes 2 and amides 3 in the presence of DBU as a catalyst in ethanol as solvent under reflux condition for 110-120 min. This method has the advantages of good yields, being environmentally friendly, straightforward protocol, short reaction times, and mild reaction conditions.

An iodobenzene diacetate (IBD)-mediated simple and green method was determined for the intramolecular oxidative cyclization of 3-aryl-2-pyridiylhydrazones of different aromatic aldehydes in an aqueous medium at room temperature. This efficient strategy provides a route to the synthesis of 3-aryl-1,2,4-triazolo[4,3-a]pyridines in water which eliminates the requirement to use costly and unsafe volatile organic solvents. All reactions were carried out by just stirring the reaction components in water at room temperature. This protocol provides a wide substrate scope and good functional group tolerance.

Chicory, or ‘Cichorium intybus’, is an erect perennial herb that can be used to treat a variety of diseases, including enteric sickness, diabetes, haemorrhoids, malaria, allergies, digestive issues, and more. The enzyme, called 6G-FFT, uses 1-kestose as a substrate for the synthesis of the more complex and branched fructans. To understand the residues involved in this conjugation reaction between 6G-FFT and 1-kestose, molecular docking study was performed. The amino acids ASP157, ASP33, SER32, TRP57, GLU211, ASP244, and GLU117 of the 6G-FFT protein showed a good interaction with the ligand by SP (Standard Precision) docking studies. Results for XP (Extra Precision) docking studies also suggest the amino acids THR153, GLU117, ASP244, GLU211, TRP57, ASP33 and ASP157 interact with the docking score of -10.6 Kcal/mol. Among these interacting amino acids, GLU117, ASP244, GLU211, TRP57, ASP33, and ASP157 were found to be common in both methods. This in silico study will be beneficial for further exploring conjugation reactions in Cichorium intybus.

In the growing field of heterocyclic compounds, phenothiazine and the associated nucleus are among the most significant potential scaffolds with excellent pharmacological activities. The knowledge of chemistry, synthetic routes, and various physicochemical parameters of these compounds draws particular attention to create a chemical library. Related compounds synthesized by various routes have diverse pharmacological functions. The exhaustive search of phenothiazine literature helps the medicinal chemists who develop the molecules for designing new drugs. A broad view of the synthetic routes has been outlined in this study. This paper includes the chemistry, physiochemical properties, and various biological activities of phenothiazine and related compounds.

New non-symmetric liquid crystal dimers, N-(4-(n-(4-(benzothiazol-2-yl)phenoxy) alkyloxy) benzylidene)-2,4-difluoroaniline (DSFCn), containing two mesogenic core units of benzothiazole and benzylideneaniline were reported. The core system was connected by a flexible alkyl spacer, -(CH2)n-(where n =2-6, 8, 10, and 12). The spectroscopic techniques were employed to confirm the molecular structure of the title compounds. Differential scanning calorimetry and polarizing optical microscopy were used to study the mesomorphic properties of the synthesized compounds. Observation under crossed polarized light reveals that compounds (n = 4, 5, 6, 8, 10, 12) are purely nematogens. The nematic phase in the dimers are caused by the presence of the lateral fluorine atoms at the benzylideneaniline core. Mesophase thermal stability has been suppressed significantly by the fluorine atom at the lateral position which increased the molecular breadth and subsequently, results in weaker overall lateral intermolecular attraction. The structure-property relationships of the dimers were inferred through comparison of thermal properties of the present dimers with those of the earlier reported analogous that do not possess any lateral substituents.

A new series of metallophthalocyanines (MPc) containing metals such as : Zn (II), Cu (II) and, Pd (II) were designed, synthesized, and characterized, using MS, IR and UV-Vis spectroscopy. A Suzuki cross-coupling reaction was investigated by using the Pd(dppf)Cl2 as a catalyst and cesium carbonate as a base to improve the yield of the precursor 2.6-di(pyridin-3-yl)- phenyl benzyl ether. The changes of metals, substituents, and positions increases the Q-band value from the monosubstituted to the octa-substituted macrocycles, and from Pd, to Cu to Zn complexes. All MPc showed quite similar IR spectra.

In this study, the interaction of Melphalan, which is an anti-cancer medicine, with Singlewall carbon nanotubes (SWCNTs) and Boron nitride nanotubes (BNNTs), was investigated. Calculations were performed by using two methods of quantum mechanics and molecular mechanics. Thermodynamic parameters and Frontier Molecular Orbitals (FMOs) of the title compounds were evaluated by using the Density Functional Theory (DFT) calculations. The Quantum Mechanics calculations proved that BNNTs are more suitable carriers for Melphalan. Moreover, the interaction of Melphalan with SWCNTs and BNNTs at different temperatures was evaluated by Monte Carlo calculations. The MM+ force field was chosen as the most efficient field, and the HCl solvent has the lowest amount of energy and proven to be the most stable solvent for the simulation. The most significant finding obtained from this study is that the results of all types of calculations are in line with each other regarding both thermodynamic properties and conformers.

Memantine hydrochloride (MH) is a first-line therapeutic drug approved by the US FDA for the management of moderate to severe Alzheimer's disease. This study involves the synthesis of memantine hydrochloride from 1-bromo-3,5-dimethyladamantane through a reaction with thiourea. The research results showed that the solvent reaction was propylene glycol (PG); the total time reaction was 5.5 hours, the temperature reaction in the first stage was 160°C and in the second stage was 80°C; the overall yield was 82.44%. The reaction intermediates were confirmed by the IR, MS,¹HNMR, and ¹³C-NMR spectra.

Globally, chronic diseases are becoming the leading cause of death. Because of the large number of patients, high medical cost, long duration of illness and the great demand for services. Diabetes is one of them and the prevalence is still rising, causing a serious physical burden to patients; it also affects a great economic burden on society. Therefore, the development of more effective antidiabetic medication is of great importance. To screen the rare chromone dimer compounds and study their inhibitory effects on type 2 diabetes mellitus. The structure was geometrically optimized and its thermodynamic properties were analyzed by DFT B3LYP-D3(BJ)/6-31G(d,p); molecular docking and molecular dynamics simulation were used to investigate the interaction of PPARγ with their ligands. In addition, its ESP and FMO were analyzed. The bis-2-(2-phenethyl)chromone derivatives have high molecular docking fractions and stable molecular dynamics simulation results, indicating that the extracts from Agarwood species bi-2-(2-phenethyl)chromone derivatives have good interactions with PPARγ. This implies that bis- 2-(2-phenethyl)chromone derivatives have good interactions with PPARγ. It is suggested that BPEC may be a natural agonist of PPARγ, which is expected to exert a more efficient hypoglycemic effect and avoid more drug side effects, laying a foundation for the research and development of anti-type 2 diabetes drugs.