Synthesis and Complexation Behavior Studies of Novel Bis-crown Ethers

The novel unique structures of bis-crown ethers were successfully synthesized from tri (propylene glycol) di-acrylate with amino- and aza-crown ethers through Michael addition. The crown ethers contained the primary and the secondary amine group such as 2-aminomethyl crown ethers, 4-aminobenzo crown ethers and 1-aza crown ethers. The newly synthesized bis-crown ethers were characterized by elemental analyses, IR, ¹H NMR, ¹³C NMR, mass spectrum, respectively. The newly synthesized host compounds of bis-crown ethers showed complex ability with various sizes of alkali metal cations such as Na⁺, K⁺, Rb⁺ and Cs⁺. The complexation behavior was examined by ¹H NMR spectroscopy and UV spectrometry.     

Synthesis and Structure of Mixed Phosphonium-iodonium Ylide

A mixed phosphonium-iodonium ylide, phenyliodoniumethoxycarbonylmethylenetriphenylphosphorane borofluoride, was synthesized. Its structure was established by means of X-ray diffraction analysis. Temperature dependence of ¹H, ¹³C, and ³¹P spectra of the ylide synthesized was investigated. A dynamic equilibrium between Z and E-isomers was observed.     

Design and Synthesis of 2,5‐Disubstituted‐1,3,4‐Oxadiazole Hybrids Bearing Pyridine and 1,2,3‐Triazole Pharmacophores

A novel series of 2,5‐disubstituted‐1,3,4‐oxadiazoles decorated with two biodynamic moieties pyridine and 1,2,3‐triazole have been successfully synthesized in good yields under mild reaction conditions. The synthesized compounds are valuable for biological activity exploration since three biodynamic moieties are covalently linked together in a single molecular framework. All the synthesized compounds were fully characterized by their detailed spectral studies IR, ¹HNMR, ¹³C NMR and Mass.     

Synthesis and Antimicrobial Activity of 2-Methyl-5-nitroaniline Derivatives:A Structure-Activity Relationship Study

A series of 2‐methyl‐5‐nitroaniline derivatives, 5a – 5k and 6a – 6f , were synthesized in order to determine their in vitro antimicrobial activity. The chemical structures of the synthesized compounds were confirmed by elemental analyses, UV‐visible, FT‐IR, ¹H NMR and ¹³C NMR spectral studies. The structure‐activity relationships of the synthesized compounds were also discussed. Among the synthesized compounds, 5f , 5d , 6b and 6e showed good antimicrobial activity compared to standard drugs.     

Reaction of methyl tetronate with some amines. Synthesis of substituted 4-aminobut-2-enolides

A series of substituted 4-aminobut-2-enolide derivatives have been synthesized by reaction of a variety of substituted amines with methyl tetronate. The ¹H and ¹³C nmr spectral analysis of all compounds synthesized are given.     

Synthesis and cytotoxicity study of pyrazoline derivatives of methoxy substituted naphthyl chalcones

2-Acetyl naphthalene reacts with various methoxy substituted benzaldehyde in the presence of 10 % sodium hydroxide solution giving functionalized chalcones. The synthesized chalcones when further reacted with hydrazine hydrate in the presence of acetic acid afforded N-acetyl pyrazolines. All the synthesized products were confirmed by various spectral data such as FTIR, ¹H NMR, ¹³C NMR, and HRMS studies. All the synthesized compounds were screened for cytotoxicity against various cell lines.     

Preparation,structure elucidation,and antioxidant activity of new bis(thiosemicarbazone) derivatives

Schiff-base–bearing new bis(thiosemicarbazone) derivatives were prepared from terephthalaldehyde and various thiosemicarbazides. FT–IR, ¹H NMR, ¹³C NMR, and UV–Vis spectroscopic methods and elemental analysis were used to elucidate the identification of the synthesized molecules. The in vitro antioxidant activity of the synthesized compounds was analysed with the 1,1-diphenyl-2-picryl hydrazyl free-radical–trapping process. The synthesized compounds exhibited lower antioxidant activity than the standard ascorbic acid. IC₅₀ values of the synthesized molecules measured from 3.81 ± 0.01 to 29.05 ± 0.11 μM. Among the synthesized compounds, compound 3 had the best antioxidant activity. Moreover, this study explained the structure–activity relationship of the synthesized molecules with different substituents in radical trapping reactions.     

Synthesis and characterization of new polyhydrazides based on 2,5-bis(mercapto-acetichydrazide)-1,3,4-thiadiazole moiety

New interesting class of novel polyhydrazides containing 1,3,4-thiadiazole moieties in the main chain was synthesized. A solution polycondensation technique was used in the synthesis of these polymers. The new monomer namely: 2,5-bis(mercapto-acetichydrazide)-1,3,4-thiadiazole III was synthesized from the nucleophilic replacement of 2,5-dimercapto-1,3,5-thiadiazole I with ethylchloroacetate, followed by hydrazinolysis. The model compound VII was synthesized from the monomer 2,5-bis(mercapto-acetichydrazide)-1,3,4-thiadiazole III with benzoyl chloride and characterized by ¹H- NMR, IR, and elemental analyses. The polyhydrazides were synthesized from the polymerization of monomer III with 4,4^′-biphenic, 3,3^′-azodibenzoyl, 4,4^′-azodibenzoyl dichlorides. These polymers were characterized by elemental and spectral analyses, viscometry and solubility. The thermal properties of these polymers were determined by thermal gravimetric analyses, and differential thermal analysis, and correlated with their structure. The crystallinity of some polymers was tested by X-ray analyses.     

CARBAMOYL AND THIOCARBAMOYL DERIVATIVES OF N-BENZYL-AMINOMETHYL-DIMETHYL-PHOSPHINE OXIDE

A series of thirteen new carbamoyl and thiocarbamoyl derivatives of N-benzyl-aminomethyl-dimethyl-phosphine oxide have been synthesized and characterized. The compounds were prepared via interaction of N-benzyl-aminomethyl-dimethyl-phosphine oxide with the corresponding isocyanates or isothiocyanates. The composition of the synthesized novel compounds was proved by elemental analysis for nitrogen and the structures were confirmed by IR,¹H-, ³¹P-³¹P{¹H} NMR spectroscopy and by mass spectrometry.     

Catalytic reduction of 4-nitrophenol by means of nanostructured polymeric Schiff base complexes

Polymeric Schiff base ligands were synthesized using 2-hydroxybenzaldehyde (L²), 4-hydroxy-3-methoxybenzaldehyde (L⁴), and 5-aminoisophthalic acid. The nanostructured complexes were then synthesized using Ni²⁺, Cu²⁺, and Mn³⁺. The ligands and complexes thus synthesized were characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis (TGA), and field-emission scanning electron microscopy. The thermal stability of the complexes was confirmed using TGA. The synthesized complexes were used as catalysts in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol in an aqueous phase in the presence of sodium borohydride. In this work, the catalytic reactivity of nanostructured complexes was compared using the rate constant (k) of the reaction. The reaction time for the reduction of 4-NP was 5–14 min for different complexes. The catalytic system based on Ni²⁺/2-hydroxybenzaldehyde was the most active and displayed reusability in the reduction of 4-NP.     

Synthesis and Biological Evaluation of Amide Derivatives of Imidazopyridine as Anticancer Agents

A series of new amide derivatives of imidazopyridine is synthesized and structures of the products are confirmed by ¹H and ¹³C NMR, and mass spectral data. The synthesized derivatives are screened for their anticancer activity against four human cancer cell lines: lung cancer (A549), breast cancer (MCF-7), melanoma cancer (A375), and colon cancer (HT-29). Six synthesized compounds exhibit more potent activity than the control drug.

     

Bis-Thiourea Bearing Aryl and Amino Acids Side Chains and Their Antibacterial Activities

Abstract

A series of symmetrical 1,3-bis thiourea 1a–e and 1,4-bis thiourea derivatives 2a–e have been successfully synthesized from the reactions of amines with 3-acetylbenzoyl isothiocyanate and 4-acetylbenzoyl isothiocyanate, respectively. All the synthesized compounds were characterized by FT-IR spectroscopy and ¹H and ¹³C NMR spectroscopy. The compounds were screened for their antibacterial activity by turbidimetric method using gram-negative bacteria (E. coli ATCC 8739) using turbidimetric method. The newly synthesized bis-thiourea derivatives bearing aryl side chains showed good antibacterial activity against E. coli. The effect of the molecular structure of the synthesized compounds on the antibacterial activity is discussed.     

Synthesis and in vitro Antimicrobial Activity of New Ethyl 2-(Ethoxyphosphono)-1-cyano-2-(substituted tetrazolo-[1,5-a]quinolin-4-yl)ethanoate Derivatives

A series of new ethyl 2‐(ethoxyphosphono)‐1‐cyano‐2‐(substituted tetrazolo[1,5‐a]quinolin‐4‐yl)ethanoate derivatives have been synthesized for the first time of tetrazolo[1,5‐a]quinoline derivatives. Elemental analysis, IR, ¹H NMR, ¹³C NMR, ³¹P NMR and mass spectral data elucidated the structures of the all newly synthesized compounds. In vitro antimicrobial activities of synthesized compounds have been investigated against Gram‐positive Bacillus subtilis, Gram‐negative Escherichia coli and two fungi Candida albicans and Aspergillus niger in comparison with standard drugs. Significantly microbiological behavior of these newly synthesized derivatives possesses significant antibacterial and antifungal activity.     

One-pot facile synthesis,crystal structure and antifungal activity of 1,2,3-triazoles bridged with amine-amide functionalities

A library of twenty five 1,2,3-triazoles bridged with amine-amide functionalities have been synthesized from reaction of N-substituted(prop-2-yn-1-yl)amines (2a–2e), 2-bromo-N-arylacetamides (4a–4e) and sodium azide through copper(I)-catalyzed alkyne-azide cycloaddition. The synthesized compounds were characterized by using FTIR, ¹H NMR, ¹³C NMR, and HRMS techniques. The structures of synthesized 5a (CCDC 1569245) and 5h (CCDC 1569249) were also confirmed by X-ray crystallography. Antifungal evaluation of newly synthesized triazoles was carried out against – Candida albicans and Aspergillus niger. Biological screening of synthesized 1,2,3-triazoles revealed moderate to good antifungal activity against tested strains.     

Synthesis and in vitro antimicrobial studies of thiodihydropyrimidine derivatives

In the present study, a series of thiodihydropyrimidine derivatives were synthesized from different substituted aromatic aldehydes, ethyl acetoacetate, and urea/thiourea using a bimetallic TUD-1 catalyst. The structures of all the synthesized compounds were characterized by melting point determination, thin layer chromatography (TLC), infrared (IR), ¹HNMR, and ¹³C-NMR values. All the synthesized compounds were screened for their antimicrobial activities against two gram positive bacteria, two-gram negative bacteria, and two fungal strains.     

Synthesis and in vitro Antibacterial Activities of 5‐(2,3,4,5‐Tetrahydro‐1H‐chromeno[2,3‐d]pyrimidin‐5‐yl)pyrimidione Derivatives

A series of novel 5‐(2,3,4,5‐tetrahydro‐1H‐chromeno[2,3‐d]pyrimidin‐5‐yl)pyrimidione derivatives have been synthesized from substituted salicylaldehydes and barbituric acid or 2‐thiobarbituric acid in water catalyzed by phase transfer catalysis of triethylbenzyl ammonium chloride (TEBA). Elemental analysis, IR, ¹H NMR, and ¹³C NMR elucidated the structures of all the newly synthesized compounds. In vitro antimicrobial activities of synthesized compounds have been investigated against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. These newly synthesized derivatives exhibited significant in vitro antibacterial activity.     

Disparity in properties of 20-mol% Eu-doped ceria synthesized by different routes

Ce_0.8Eu_0.2O_2?δ was synthesized by conventional solid state route as well as wet chemical route (i.e. cation complexation, combustion method). The crystallite size obtained for cation complexation and combustion samples is 14 and 19 nm while their surface area is 11.70 and 29.63 m²g^?1 respectively. Cation complexation synthesized product lead to formation of agglomerates and hence the sintered sample showed porosity compared to combustion synthesized sample. However, despite high packing density the combustion synthesized sample showed lower grain boundary, total conductivity than cation complexation synthesized product due to the formation of siliceous film at the grain boundary.     

Synthesis and antimicrobial evaluation of tricyclic macrocycles containing a chalcone moiety

A series of new tricyclic macrocycles containing a chalcone moiety were synthesized from chalcones through alkylation using different dibromoalkanes. All the synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, and mass spectral data and evaluated for their in vitro antimicrobial activity.     

Synthesis,Characterization, and DGAT1 Inhibition of New 5‐Piperazinethiazole and 5‐Piperidinethiazole Analogs

In this study, a novel series of 5‐piperazinethiazole 2,2‐dimethylbutanoic acid and 5‐piperidinethiazole 2,2‐dimethylbutanoic acid derivatives have been synthesized. Structures of the newly synthesized compounds have been elucidated using ¹H‐NMR, ¹³C‐NMR, high‐resolution mass spectroscopy, and high‐performance liquid chromatographic analysis. The synthesized derivatives have been evaluated in vitro for their ability to inhibit the enzyme diacylglycerol acyltransferase 1 responsible for triglyceride biosynthesis.     

Design,Synthesis, and Biological Screening of Novel Anthranilic Diamides

Three series of new anthranilic diamide derivatives containing sulfide, N‐cyanomethylsulfilimine, and N‐cyanomethylsulfoximine groups were designed and synthesized by combining the active substructures of anthranilic diamides and sulfoxaflor. The structures of all newly synthesized compounds were confirmed by IR and ¹H/¹³C‐NMR, and some of them were confirmed by elemental analysis or HRMS too. The synthesized compounds were screened for their insecticidal and fungicidal activities. Bioasssay results indicated that some of the synthesized compounds possessed certain degrees of insecticidal activity against Mythimna separata. However, some compounds exhibited good fungicidal activity against Sclerotinia sclerotiorum.