New Nitro-Laterally Substituted Azomethine Derivatives; Synthesis, Mesomorphic and Computational Characterizations

Two new homologues series, based on two rings of the azomethine central group bearing the terminal alkoxy group of various chain lengths, were prepared. The alkoxy chain length varied between 6 and 16 carbons. The other terminal wing in the first series was the F atom, and the compound is named N-4-florobenzylidene-4-(alkoxy)benzenamine (In). The second group of compounds included a lateral NO2 substituent in addition to the terminal F atom, named N-(4-fluoro-3-nitrobenzylidene)-4-(alkyloxy)aniline (IIn). Mesomorphic and optical properties were carried out via differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Elemental analyses, FT-IR, and NMR spectroscopy were carried out to elucidate the molecular structures of the synthesized groups. Mesomorphic investigations indicated that all the synthesized homologues (In) were monomorphic, possessing the smectic A (SmA) phase monotropically, while the second group (IIn) members were non-mesomorphic. The experimental data indicated that the formation of the mesophase is affected by the protrusion of the lateral nitro group. The disruption of the mesophase in the second group was attributed to the increase of its molecular width, which affects its lateral intermolecular interactions. The computational simulations were in agreement with the experimental data. On the other hand, the location of NO2 group within the molecular geometry increased the melting temperature of the molecule, and thus, affected their thermal and physical properties. By discussing the estimated parameters, it was found that the molecular architecture, the dipole moment, and the polarizability of the investigated compounds are highly affected by the electronic nature and position of the terminal and lateral substituents as well as their volumes

Ball Milling Promoted N-Heterocycles Synthesis

In the last years, numerous protocols have been published using ball milling for organic synthesis. Compared to other methods such as microwave or ultrasound irradiation and ionic liquids, ball mill chemistry is an economical, and ecofriendly method in organic synthesis that is rather underrepresented in the knowledge of organic chemists. The aim of this review is to explore the advantages of the application of ball milling in synthesis of N-heterocyclic compounds

Characterization, DFT calculations and dyeing performance on polyester fabrics of some azo disperse dyes containing pyrazole ring

A number of azo pyrazole derivatives and novel Schiff bases derived from azo diamino pyrazole were synthesized. These included 4-(2-arylhydrazono)-4H-pyrazole-3,5-diamines and N3,N5-dibenzylidene-4-(2-arylhydrazono)-4H-pyrazole-3,5-diamines. The chemical structures of the novel azo dyes were determined using UV–visible, IR, 1H NMR, and 13C NMR spectroscopy. Dyeing process and tautomerism of the aforementioned azo compounds were predicted using DFT calculations. The electronic absorption spectra in methanol were observed and compared to those computed using B3LYP/6-31G(d,p). The dyeing performance of the produced disperse dyes was examined on polyester. The degree of exhaustion and the fastness properties of the dyed samples in terms of washing, perspiration, scorch, and light fastness were assessed. Moreover, the reflectance and color strength of the synthesized dyes were measured and discussed

A Global Perspective on a Review of a Three-Year C-Nucleosides Development: 2009-2011

Abstract C-Nucleosides rema in among the most challenging modified nucleosides to build for evaluation of their biological act ivities. This review includes a brief introduction of the C-Nucleosides classification and focuses on what has been done during a three year period (2009)(2010)(2011) fo r their synthetic approaches and structural modifications. It spots locations of work and synthetic tactics, then correlate that to international vs. national transformat ion of methodologies. For sustainable developments science diplomacy may provide a foru m for international collaborative research, wh ich leads to intriguing topics of potential applicat ions

Chitosan Capped Copper Oxide Nanocomposite: Efficient, Recyclable, Heterogeneous Base Catalyst for Synthesis of Nitroolefins

In this article, chitosan copper oxide nanocomposite was synthesized by the solution casting method under microwave irradiation. The nanocomposite solution was microwave irradiated at 300 watt for 3 min under optimal irradiation conditions. By suppressing particle agglomeration, the chitosan matrix was successfully used as a metal oxide stabilizer. The goal of this research was to create, characterize, and test the catalytic potency of these hybrid nanocomposites in a number of well-known organic processes. The prepared CS-CuO nanocomposites were analyzed by different techniques, including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). Moreover, energy-dispersive X-ray spectroscopy (EDS) was used to measure the copper content in the prepared nanocomposite film. The finger-print peaks in the FTIR spectrum at around 632–502 cm−1 confirmed the existence of the CuO phase. The CS-CuO nanocomposite has been shown to be an efficient base promoter for nitroolefin synthesis via the nitroaldol reaction (Henry reaction) in high yields. The reaction variables were studied to improve the catalytic approach. Higher reaction yields, shorter reaction times, and milder reaction conditions are all advantages of the technique, as is the catalyst’s reusability for several uses

Synthesis and Antimicrobial Activity of Some New Substituted Quinoxalines

A number of new symmetrically and asymmetrically 2,3-disubstituted quinoxalines were synthesized through functionalization of 2,3-dichloroquinoxaline (2,3-DCQ) with a variety of sulfur and/or nitrogen nucleophiles. The structures of the obtained compounds were established based on their spectral data and elemental analysis. The antimicrobial activity for the prepared compounds was investigated against four bacterial species and two fungal strains. The symmetrically disubstituted quinoxalines 2, 3, 4, and 5 displayed the most significant antibacterial activity, while compounds 6a, 6b, and the pentacyclic compound 10 showed considerable antifungal activity. Furthermore, compounds 3f, 6b showed broad antimicrobial spectrum against most of the tested strains

Pyrimidines-Based Heterocyclic Compounds: Synthesis, Cytoxicity Evaluation and Molecular Docking

A variety of structurally different pyrimidines were synthesized. Elemental analysis, FT-IR, 1H NMR, and 13C NMR spectroscopy were used to confirm the chemical structures of all prepared compounds. The synthesized pyrimidines were screened against the growth of five human cancer cell lines (prostate carcinoma PC3, liver carcinoma HepG-2, human colon cancer HCT-116, human breast cancer MCF-7, human lung cancer A-549), and normal human lung fibroblasts (MRC-5) using MTT assay. Most of the screened pyrimidines have anti-proliferative activity on the growth of the PC3 cell line. Compounds 3b and 3d were more potent than the reference vinblastine sulfate (~2 to 3 × fold) and they can be considered promising leads for treating prostate cancer disease. Moreover, the screened compounds 3b, 3f, 3g, 3h, and 5 were assessed according to the values of their selectivity index (SI) and were found to be more selective and safer than vinblastine sulfate. Furthermore, using in silico computational tools, the physicochemical properties of all pyrimidine ligands were assessed, and the synthesized compounds fall within the criteria of RO5, thus having the potential to be orally bioavailable

Synthesis and Antimicrobial Activity Screening of Piperazines Bearing N,N′-Bis(1,3,4-thiadiazole) Moiety as Probable Enoyl-ACP Reductase Inhibitors

A new N,N′-disubstituted piperazine conjugated with 1,3,4-thiadiazole and 1,2,4-triazole was prepared and the chemical structures were identified by IR, NMR and elemental analysis. All the prepared compounds were tested for their antimicrobial activity. The antimicrobial results indicated that the tested compounds showed significant antibacterial activity against gram-negative strains, especially E. coli, relative to gram-positive bacteria. Docking analysis was performed to support the biological results; binding modes with the active site of enoyl reductase amino acids from E. coli showed very good scores, ranging from −6.1090 to −9.6184 kcal/mol. Correlation analysis was performed for the inhibition zone (nm) and the docking score

New Advanced Liquid Crystalline Materials Bearing Bis-Azomethine as Central Spacer

In this study, a homologous series of novel liquid crystalline compounds bearing the bis-azomethine central linkage (–CH=N-N=CH–), namely ((1E,1′E)-hydrazine-1,2-diylidenebis(methanylylidene))bis(4,1-phenylene) dialkanoate (In), was synthesized, and the mesophase and thermal properties were investigated theoretically and experimentally. The molecular structures of the prepared compounds were determined using elemental analysis, NMR, and FT-IR spectroscopy. The mesophase transitions were detected by differential scanning calorimetry (DSC), and the mesophases were identified using polarized optical microscopy (POM). The results indicated that the derivative with the shortest length (I5) was purely nematogenic, while the other homologues (I9 and I15) possessed SmC mesophases. The optimal geometrical structures of the investigated group were derived theoretically. The estimated results demonstrated that all homologues were mesomorphic, and their type depended on the length of the terminal chains. Computations based on density functional theory (DFT) were used to explain the experimental data. The calculated dipole moment, polarizability, thermal energy, and molecular electrostatic potential all showed that it was possible to predict the mesophase type and stability, which varied according to the size of the molecule

Induced Nematic Phase of New Synthesized Laterally Fluorinated Azo/Ester Derivatives

A new series of laterally fluorinated mesomorphic compounds, namely 2-fluoro-4-((4-(alkyloxy)phenyl)diazenyl)phenyl 4-substitutedbenzoate (Inx) were prepared and evaluated for their mesophase behavior. The synthesized series constitutes five members that possess different terminally attached polar groups (X). Their molecular structures were confirmed by elemental analyses and both FT-IR and NMR spectroscopy. Examination of the prepared derivatives was conducted via experimental and theoretical tools. Mesomorphic investigations were carried by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). DSC and POM measurements indicated that except for the un-substituted analogue, all other derivatives were purely nematogenic, possessing their nematic (N) mesophase enantiotropically. This is to say that insertions of terminal polar substituents on their mesogenic structures induced the N phase. In addition, the location of lateral and terminal polar moieties played a considerable role in achieving good thermal N stability. Computational calculations were investigated to determine the deduced optimized molecular structures. Theoretical data indicated that both size and polarity of the terminal substituent (X) have essential impact on the thermal parameters and optical properties of possible geometries