Hydrazyl,Nitronyl-, and imino-nitroxides: Synthesis,properties and reaction with nitric oxide and nitrogen dioxide

Ten novel and stable free radicals of nitronyl-, imino-nitroxide and hydrazyl type compounds were synthesized and their physico-chemical properties investigated. UV-Vis and ESR spectroscopic data, as well as the lipophilicities and specific hydrophobic areas of the compounds are compiled. The reaction of these radical compounds with nitric oxide and nitrogen dioxide was also investigated. The radicals synthesized, show selectivity in their reaction with these nitric oxides, depending on their structure (nitronyl-nitroxide radicals react with NO, while hydrazyl radicals react with NO₂). The processes are easily monitored by UV-Vis or ESR spectroscopy.     

Synthesis and antimicrobial evaluation of some novel dithiolane,thiophene, coumarin,and 2-pyridone derivatives

Novel 2-cyano-N-[1-(naphtha-2-yl)ethylidene] acetohydrazide 1 was utilized as key intermediate for the synthesis of some new dithiolane, thiophene, coumarin, 2-pyridone, and other related products containing a hydrazide moiety. Newly synthesized compounds were characterized by elemental analyses and spectral data (IR, ¹H NMR and mass spectra). The antimicrobial activity of the synthesized compounds was evaluated.     

Synthesis, characterization and antifungal evaluation of 5-substituted-4-amino-1,2,4-triazole-3-thioesters

A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard.     

Synthesis and Antioxidant Evaluation of Some Novel Thiophene,Pyrazole, Chromene,Pyrazolotriazine Derivatives Bearing Sulfonamide Moiety

As a part of ongoing studies in developing new potent antioxidant agents, N‐[4‐(aminosulfonyl)phenyl]‐2‐cyanoacetamide ( 3 ) was utilized as key intermediate for the synthesis of some new thiophene, chromene, and pyrazolotriazine pyridine derivatives. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, ¹H‐NMR, and mass spectral data. Representative compounds of the synthesized products were tested and evaluated as antioxidant. Compounds 7 and 30 are promising compounds.     

Novel 1,4-benzothiazine derivatives: synthesis,crystal structure,and anti-bacterial properties

In order to develop relatively small molecules as pharmacologically active molecules, novel 1,4-benzothiazine derivatives with triazole and oxazolidinone were synthesized. In this study, a series of 1,2,3-triazolylmethyl-1,4-benzothiazine derivatives were developed by exploiting a click chemistry reaction using a CuI-catalyzed Huisgen [3 + 2] cycloaddition. Starting from 2-(substituted)-3,4-dihydro-2H-1,4-benzothiazi-3-one, a number of 1,4-benzothiazine derivatives were also synthesized using different alkylating agents to give a 4-(substituted)-2-(substituted)-3,4-dihydro-2H-1,4-benzothiazi-3-one in good yields. The crystal and molecular structure of compound oxazolidin-2-one in basic benzothiazine was established by single-crystal X-ray diffraction. The newly synthesized products were subjected to in vitro biological evaluation. The result indicated that the compounds show convincing antibacterial activities against different microorganisms. All structures of the synthesized compounds were elucidated on the basis of spectral analyses and chemical reactions.     

Precursor route synthesis and thermal contraction of compounds ZrW_(2-x)Mo_xO_8 (x=0, 0.4, 0.6, 0.8, 1.2, 1.6)

A series of title compounds as well as their precursors were synthesized by precursor route. Their PXRD patterns were characterized with ZrW2O8 or ZrMo2O8 model by Rietveld method. The thermal contractions of the compounds were determined according to the variable-temperature PXRD data and NTE coefficients were presented. The two-phase mixture of ZrW0.4Mo1.6O8 was also analyzed individually.     

Synthesis,characterization and pharmacological investigations of some novel heterocyclic derivatives incorporating pyrene and sugar moieties

A series of substituted pyrene derivatives 2–15 incorporated heterocyclic and sugar moieties were synthesized and evaluated as antiviral activities using 1-acetylpyrene as a starting material. The structure assignment of the new compounds was based on chemical and spectroscopic evidence. The detailed synthesis, spectroscopic data and pharmacological activities of the synthesized compounds were reported.     

Design,Synthesis, and Docking Studies of Novel Dimethyl Triazene Incorporated Thiazolyl Pyrazolines for Anticancer Activity

A novel series of dimethyl triazene incorporated thiazolyl pyrazolines have been designed on the basis of hybridization and also in support with combi‐targeting approach. The designed compounds were synthesized through facile synthetic methods, and the compounds were confirmed by ¹H NMR, ¹³C NMR, MS, and elemental analysis. Further, compounds were screened for in vitro anticancer activity against human breast cancer (MCF‐7) and human colon cancer (HT‐29) cell lines by MTT assay. Among all the tested compounds, compound 9b showed highest activity against both the cell lines in comparison with reference drug, Cisplatin. In addition, the synthesized compounds were docked into VEGFR‐2 kinase (PDB code: 2XIR) to explore their binding interactions at the active site. The compounds showed essential key interactions as that of known VEGFR‐2 inhibitors, and hence, the synthesized compounds may be considered as molecular scaffolds for anticancer activity.     

Quinoline and 2-nitroimino-1, 3-diazacycloalkane hybrids: Design,synthesis and insecticidal activity

A library of new hybrid molecules comprising quinoline, 2-nitroimino-1, 3-diazacycloalkane motifs were designed and synthesized as plausible neonicotinoid analogues. These compounds were synthesized from 2-chloro/aryloxy-3-formyl quinolines and guanidine nitrate with the coupling of 2-chloro/aryloxy-3-(chloromethyl)quinolines, 2-nitroimino-1, 3-diazacycloalkanes under phase transfer catalysis (PTC) as crucial step. All the compounds were obtained in excellent yields (80–90%) and were characterized by ¹H, ¹³C NMR and mass spectrometry. The newly generated compounds were screened for insecticidal activity against aphids in safflower field and some of them displayed moderate activity.     

Synthesis,characterization, DNA binding,antibacterial, and antioxidant activity of new bis-phthalimides

New bis-phthalimides were synthesized by 2: 1 condensation of phthalic anhydride and tetrachlorophthalic anhydride with 1,2,4-triazole-3,5-diamine, pyridine-2,6-diamine, and 4-hydroxypyrimidine- 2,6-diamine. The synthesized compounds were characterized by elemental analyses and IR, ¹H NMR, and mass spectra. Their interaction with calf thymus DNA (ct-DNA) was studied by UV-Vis spectrophotometry, cyclic voltammetry, and viscosity measurements, which revealed intercalative mode of binding to ct-DNA. Antibacterial activity of the synthesized compounds against Escherichia coli and Streptococcus mutans was assessed in vitro by the agar well diffusion method. The antioxidant activity of these compounds was estimated by DPPH assay.     

Synthesis, Analgesic, and Antiparkinsonian Profiles of Some Pyridine, Pyrazoline, and Thiopyrimidine Derivatives

Summary. A series of substituted pyridine, pyrazoline, and thiopyrimidine derivatives were synthesized from 3-acetylpyridine, which was prepared from nicotinic acid as a naturally starting material. The pharmacological screening showed that many of these compounds have good analgesic and antiparkinsonian activities comparable to Voltarene^? and Benzatropine^? as reference drugs. The structure assignment of the new compounds is based on chemical and spectroscopic evidence. The detailed synthesis, spectroscopic data, and pharmacological properties for synthesized compounds are reported.     

Polynitro Containing Energetic Materials based on Carbonyldiisocyanate and 2, 2‐Dinitropropane‐1, 3‐diol

New polynitro compounds containing a carbonyl biscarbamate moiety derived from the precursor carbonyldiisocyanate were synthesized. In addition, 2, 2‐dinitropropane‐1, 3‐diyl bis(2, 2,2‐trinitroethylcarbamate) and 2, 2‐dinitropropane‐1, 3‐diyl bis(2, 2,2‐trinitroethyl) dicarbonate, were synthesized using 2, 2‐dinitropropane‐1, 3‐diol as starting material. The compounds were characterized by using the analytical methods, single‐crystal X‐ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, and mass spectrometry. The thermal behavior was investigated with DSC measurements. The suitability of the compounds as potential oxidizers in energetic formulations was determined. The heats of formation of the compounds were calculated with GAUSSIAN 09. The detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code. For a secure handling of the materials, the sensitivity towards impact, friction, and electrical discharge was tested using the BAM drop hammer, BAM friction tester as well as a small‐scale electrical discharge device, respectively.     

Synthesis, Mass Spectrometric Studies, and Biological Evaluation of 3,5-Dimethoxyhomophthalic Acid and Related Compounds

3,5-Dimethoxyhomophthalic acid was synthesized in four steps from 3,5-dimethoxycinnamic acid via a series of reactions including cyclization of 3-(3',5'-dimethoxyphenyl)propionic acid to 5,7-dimethoxy-1-indanone and oxidative decomposition of methyl-2-hydroxy-2-[5,7-dimethyoxy-1-oxo-1H-inden-2(3H)-ylidene]acetate to 3,5-dimethoxyhomophthalic acid.The synthesized compounds were characterized by elemental analysis,IR,1H NMR,and MS.The biological evaluation experiments of 3,5-dimthoxyhomophthalic acid and the related synthesized compounds were also carried out.Naturally occurring biologically active isocoumarins were prepared in a single step by the condensation of the homophthalic acid with appropriate acid chlorides.     

Design,synthesis, characterization,computational study and in-vitro antioxidant and anti-inflammatory activities of few novel 6-aryl substituted pyrimidine azo dyes

A series of 6-aryl substituted pyrimidine azodyes were synthesized by coupling of phenyl pyrimidine 2-amine with different aromatic amines. The synthetic compounds were screened for their in-vitro antioxidant and anti-inflammatory activities. The characterization of the synthesized compounds was carried out by IR, ¹H NMR, ¹³C NMR and Mass spectrophotometry. Computational study of designed compounds was done by OCHEM, Molinspiration cheminformatics, Datawarrior, and Swiss ADME. DPPH assay was used to determine the antioxidant activity and heat hemolysis method for anti-inflammatory activity.     

Synthesis and antitumor activity evaluation of some 1, 2, 4-triazine and fused triazine derivatives

Reactions of 3-hyrazino-5,6-diphenyl-1,2,4-triazine with various carbonyl compounds such as ethyl acetoacetate, acetylacetone, benzoin, isatin, phthalic anhydride, phenyl isocyanate and acetic anhydride were discussed. Its reactions with α, β unsaturated compounds such as arylidinemalononitrile, diethyl acetylenedicarboxylate, dibenzylidine hydrazine were studied. These reactions led to the formation of various triazine and fused-triazine derivatives. The antitumor activity of the synthesized compounds was tested against HePG2 and MCF-7 cell lines. Some of the tested compounds were most active, whereas other compounds exhibited little or no activity.     

One-pot three-component azide-alkyne cycloaddition: Synthesis of new pyrazole, 1,2,3-triazole,and oxadiazole tethered and their anti-inflammatory,quantitative structure-activity relationship,and docking studies

A simple and efficient one-pot three-component azide-alkyne cycloaddition of 5-chloro-1-phenyl-pyrazole-4-carbaldehyde with 2-(prop-2-yn-1-ylthio)-5-(substituted phenoxy)methyl-1,3,4-oxadiazole and sodium azide is reported. The newly synthesized compounds were characterized by spectral and analytical data. They were screened for in vitro anti-inflammatory activity by bovine serum albumin denaturation assay. All the tested compounds showed moderate anti-inflammatory activity, whereas three compounds ( 4d , 4i , and 4k ) showed excellent activity comparable with that of the standard drug diclofenac sodium. The quantitative structure-activity relationship (QSAR) study was carried out for anti-inflammatory activities of the synthesized compounds and developed a QSAR model. Inspired by their in vitro anti-inflammatory activities, they were docked to the active site of COX-2 to know the anti-inflammatory potency in silico.     

Design of novel substituted phthalocyanines; synthesis and fluorescence,DFT, photovoltaic properties

The 4-(2-[3,4-dimethoxyphenoxy] phenoxy) phthalonitrile was synthesized as the starting material of new syntheses. Zinc, copper, and cobalt phthalocyanines were achieved by reaction of starting compound with Zn(CH3COO)2, CuCl2, and CoCl2 metal salts. Basic spectroscopic methods such as nuclear magnetic resonance electronic absorption, mass and infrared spectrometry were used in the structural characterization of the compounds. Absorption, excitation, and emission measurements of the fluorescence zinc phthalocyanine compound were also investigated in THF. Then, structural, energy, and electronic properties for synthesized metallophthalocyanines were determined by quantum chemical calculations, including the DFT method. The bandgap of HOMO and LUMO was determined to be chemically active. Global reactivity (I, A, η, s, μ, χ, ω) and nonlinear properties were studied. In addition, molecular electrostatic potential (MEP) maps were drawn to identify potential reactive regions of metallophthalocyanine (M-Pc) compounds. Photovoltaic performances of phthalocyanine compounds for dye sensitive solar cells were investigated. The solar conversion efficiency of DSSC based on copper, zinc, and cobalt phthalocyanine compounds was 1.69%, 1.35%, and 1.54%, respectively. The compounds have good solubility and show nonlinear optical properties. Zinc phthalocyanine gave fluorescence emission.     

Synthesis,Characterization, and Biological Activity of Substituted Thiazole-5-carboxaldehydes and Their Ylidenenitriles Derivatives

The Vilsmeier–Haack reaction of 2-amino -4-(4-substituted phenyl)-thiazoles 1, in the presence of micellar media, gives formylated derivatives 2, which upon hydrolysis afforded thiazole-5-carboxaldehydes 3. Microwave-assisted Knoevenagel condensation of 3 with active methylene compounds, in the presence of piperidine as catalyst, gives excellent yields of ylidenenitrile compounds 4. The structures of the newly synthesized compounds were established on the basis of elemental analysis, IR, ¹H NMR, and ¹³C NMR spectral analysis. All newly synthesized compounds were screened for antibacterial activity using two Gram-positive and one Gram-negative bacterial species and their antifungal activity was screened using two fungal species.     

Design,synthesis, evaluation,and molecular dynamic simulation of triclosan mimic diphenyl ether derivatives as antitubercular and antibacterial agents

In the present work, we have explored triclosan mimic diphenyl ether derivatives as inhibitors of Mycobacterium tuberculosis enoyl acyl carrier protein reductase (InhA) using a structure-based drug design approach. The virtual library of diphenyl ethers was designed and compounds with acceptable absorption, distribution, metabolism, excretion, and toxicity properties were docked. The compounds with higher dock score (5a-g) than triclosan were synthesized, characterized, and evaluated for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv. Among the synthesized compounds, compounds 5f and 5c appeared to be the most promising with minimum inhibitory concentration of 18 μM and 36 μM respectively. The molecular dynamics simulation study of the most active compound 5f and triclosan was performed, which correlates with its activity in comparison with triclosan. All the compounds were further evaluated for cytotoxicity studies against Vero, and HepG2 were found to be safe. Furthermore, compound 5f was evaluated for in vitro cytotoxicity against mouse macrophage cell lines (RAW 264.7), and the study indicated its safety in eukaryotes at 50-μM concentration. In addition, compounds 5a-g were also screened for their in vitro antibacterial activity against two gram-positive and two gram-negative bacteria by resazurin-based microtiter dilution assay method. Among the synthesized compounds, 5f and 5b appeared to be promising, against various gram-positive and gram-negative microorganisms, indicating its broad-spectrum potential.

     

Synthesis,characterization, and investigations of antimicrobial activity of benzopyrans,benzofurans and spiro[4.5]decanes

In this study, the radical cyclization reactions of cyclic 1,3-dicarbonyl compounds (1a–c) and α,β-unsaturated alcohols (2a–d) through Mn(OAc)₃ were performed. A series of biologically interesting dihydropyrans (3–5) and dihydrofurans (6–18) were synthesized as a result of these reactions. Spiro compounds (19–20) were obtained from the reactions of 1,3-dicarbonyl compounds and (E)-2,4-diphenyl-but-3-en-2-ol (2e). The unique structure of compound 19 was also confirmed by X-ray crystallography. In addition, the antibacterial activities of synthesized compounds were screened against some bacteria. Their zone diameters showed better results than some known antibiotics.