Synthesis and properties of polymers containing aromatic amino groups in the main chain and their glass-forming model compounds

Polymers containing di(carbazol-3-yl)phenylamine and N,N^′-di(carbazol-3-yl)-N,N^′-diphenyl-1,4-phenylenediamine units in the main chain have been synthesized by a modified Ullmann condensation as a key step. The number-average molecular weights of the polymers synthesized were in the range of 2300-4800 with a molecular weight distribution of 1.42-2.25. Well defined model compounds of the title polymers were synthesized by stepwise reactions. All the materials exhibit high thermal stability with the initial weight loss temperatures exceeding 320 °C and form glasses. Their glass transition temperatures range from 102 to 216 °C as characterised by differential scanning calorimetry. The electron photoemission spectra of thin films of the synthesized compounds have been recorded and the ionisation potentials of 5.0-5.1 eV have been established.     

Hole-transporting [3,3′]bicarbazolyl-based polymers and well-defined model compounds

Polymers containing bicarbazolyl moieties in the main chain have been synthesized by the modified Ullmann coupling reaction from 9H,9′H-[3,3′]bicarbazolyl and different dihalo derivatives. The number-average molecular weights of the polymers synthesized were in the range of 2500-6200 with a molecular weight distribution of 1.6-3.1. Well-defined model compounds for the polymers have been synthesized by stepwise reactions. All these compounds have been found to form glasses with glass transition temperatures in the range of 57-119 °C as characterised by differential scanning calorimetry. The electron photoemission spectra of the compounds have been recorded and the ionisation potentials of 5.35-5.4 eV have been established. Room temperature hole drift mobility of the synthesized compounds molecularly dispersed in a polymer host range from 10⁻⁶ to 3 × 10⁻⁵ cm²/V s at an electric field of 10⁶ V/cm at the room temperature.     

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 of 2-Amino-4-(2-hydroxynaphthyl)-4H-chromene-3-carbonitriles by Michael Addition and Their Transformation into New Pentacyclic Compounds

2-Amino-4-(2-hydroxynaphthyl)-4H-chromene-3-carbonitriles were synthesized by Michael addition of various 3-cyanoiminocoumarins and β-naphthol in good yield. The heterocyclization of these materials in an acidic medium leads new heterocyclic compounds, which have not previously been described, in moderate to good yields and good selectivity. The synthesized compounds were characterized by infrared, ¹H NMR, ¹³C NMR, two-dimensional NMR, and elemental analysis.     

Synthesis of some acylated 2-pyrazoline and chalcone derivatives

α-Haloesters containing the chalcone structure and α-haloamides containing the pyrazoline ring have been synthesized by reaction of substituted hydroxy chalcones and pyrazoline derivatives (prepared as reported elsewhere; J Chem 8(4):1574–1581, 2011) with chloroacetyl chloride in dry THF in the presence of Et₃N. The structures of the synthesized compounds were confirmed by IR, ¹H NMR, and (for some compounds) ¹³C NMR spectroscopy.     

Synthesis and antimicrobial activity of 2,4-diaryl-2,3-dihydrobenzo[b][1,4]thiazepines

A new series of structurally diverse 2,3-dihydrobenzo[b][1,4]thiazepines (2,3-dihydro-1,5-benzothiazepines) with substituted phenyl groups at C(2) and C(4) have been synthesized by reaction of 3-(5-bromo-2-methoxyphenyl)-1-arylpropen-1-ones with 2-aminobenzenethiols. The structures of all the synthesized compounds were confirmed by their analytical and spectral data (IR, ¹H NMR, ¹³C NMR). All the synthesized compounds were evaluated for antibacterial and antifungal activity against a variety of bacterial and fungal strains and interesting results were obtained. Some of the compounds had antibacterial and antifungal activity comparable to that of ciprofloxacin and fluconazole.     

1,2,3‐Triazole derivatives of 3‐ferrocenylidene‐2‐oxindole: Synthesis,characterization, electrochemical and antimicrobial evaluation

A series of bioactive, triazole‐linked benzyl, aryl, sugar and aliphatic conjugates of 3‐ferrocenylidene‐oxindole have been synthesized. A facile 1,3‐dipolar‐Huisgen coupling reaction of the respective azides with the 3‐ferrocenylidene‐oxindole N‐propargyl moiety ( 3 ) gave the corresponding conjugates ( 5a–n ). All the newly synthesized compounds ( 5a–n ) were characterized by ¹H‐NMR, ¹³C‐NMR, HRMS, Fourier transform‐infrared spectroscopy and elemental analysis. The UV–Vis and electrochemical studies of these compounds were performed in dimethylsulfoxide solutions. The structure of compound ( 3 ) was determined by single crystal X‐ray diffraction study. These compounds exhibited moderate to good antimicrobial activity against Gram‐positive and Gram‐negative strains.     

Novel Approach for Rapid and Efficient Synthesis of 2‐(3‐(4‐Aryl)‐1‐isonicotinoyl‐4,5‐dihydro‐1H‐pyrazol‐4‐yl)‐3‐phenylthiazolidin‐4‐one Derivatives and Screened Their Antimicrobial Activity

A series of compounds, viz. 2‐(3‐(4‐aryl)‐1‐isonicotinoyl‐4,5‐dihydro‐1H‐pyrazol‐4‐yl)‐3‐phenylthiazolidin‐4‐one 4 ( a – n ), have been synthesized by reaction of 3 ( a – n ) with thioglycolic acid in the presence of zinc chloride. Compounds 3 ( a – n ) have been synthesized by amination of formylated pyrazoles 2 ( A – B ), which were synthesized by formylation of 1 ( A – B ) by Vilsmeier–Haack reagent (POCl₃/DMF). Compounds 1 ( A – B ) were synthesized by condensation of hydrazide and substituted acetophenones under conventional method and microwave irradiation method. These compounds were identified on the basis of melting point range, Rf values, infrared, ¹H NMR, and mass spectral analysis. These compounds were evaluated for their in vitro antimicrobial activity, and their minimum inhibitory concentration was determined. Among them, compound 4b and compound 4l possess appreciable antimicrobial and antifungal activities. Antibacterial activity results showed that compounds containing electron‐withdrawing groups were more active than compounds containing electron‐releasing groups.     

Synthesis and spectroscopic characterization of asymmetric Schiff bases derived from 4′-formylbenzo-15-crown-5 containing recognition sites for alkali and transition metal guest cations

Asymmetric salen-type Schiff base ligands have been synthesized via a stepwise approach. In the first step, mono-Schiff base compounds were prepared by condensation of salicylaldehyde, 2-hydroxy-3-methoxybenzaldehyde, 2-hydroxy-5-methoxybenzaldehyde and 2-hydroxy-1-naphthaldehyde with hydrazine hydrate. These compounds were then reacted with 4′-formylbenzo-15-crown-5 to prepare asymmetric ligands. ¹H-NMR spectra indicate that the mono- and asymmetric bis-Schiff base compounds exist in both (E) and (Z) isomeric forms in CDCl₃ solution. The asymmetric crown compounds form crystalline 1:1 (Na⁺:ligand) complexes with sodium perchlorate. Homo-metallic Ni(II) and Zn(II) complexes with 1:2 (metal:ligand) stoichiometries have also been synthesized. The results indicate that the Schiff base ligands coordinate through the azomethine nitrogen and phenolic oxygen.     

Synthesis and biological evaluation of novel piperidin-4-ol derivatives

Abstract  

A series of novel piperidin-4-ol derivatives were designed, synthesized, and evaluated for potential treatment of HIV. The compounds were obtained via an efficient synthetic route in excellent yields and have been characterized by ¹H NMR, ¹³C NMR, MS, and elemental analysis. The CCR5 antagonistic activities of the compounds have also been evaluated.     

Microwave assisted selective synthesis of (<Emphasis Type="Italic">E</Emphasis>)-1-(4-Chloro-7-hydroxy-2-aryl-2<Emphasis Type="Italic">H</Emphasis>-chromen-6-yl)-3-arylprop-2-en-1-ones and their antimicrobial activity

A series of new (E)-1-(4-chloro-7-hydroxy-2-aryl-2H-chromen-6-yl)-3-arylprop-2-en-1-ones (2a–2f) have been synthesized by selective mono cyclization of 4,6-dicinnamoyl resorcinols (1a–1f) using Vilsmeier–Haack reagent under conventional heating and microwave irradiation. The structures of the synthesized compounds have been elucidated by elemental analysis, IR, ¹H NMR, ¹³C NMR and Mass spectral data. The synthesized compounds were tested in vitro for antimicrobial activity.     

Microwave synthesis,anti-oxidant and anti-tumor activity of some nucleosides derived 2-oxonicotinonitrile

Abstract

A facile and convenient synthesis of novel cyclic and acyclic nucleoside derivatives incorporating 2-oxo-1,2-dihydropyridine-3-carbonitrile moiety has been described. The aglycons 3a,b were coupled with different activated halosugars such as glucosyl, galactosyl, lactosyl bromides and peracetylated ribose, in addition to, acyclic sugar as 4-bromobutylacetate and 2-acetoxyethoxymethyl bromide in basic medium under conventional and microwave irradiation. Deprotection of the synthesized nucleosides was obtained in presence of Et₃N/MeOH and few drops of water. The structures of the synthesized compounds have been deduced from their elemental analyses and spectral data (IR, ¹H NMR, and ¹³C NMR). Some of the synthesized compounds were screened as antioxidant and anticancer agents. Good and moderate anticancer activities against HepG-2, PC-3 and HCT116 were observed in vitro for some compounds.     

Experimental, theoretical and biological activity study on 1-(4,5-dihydro-3-arylpyrazol-1-yl)-2-(1H-1,2,4-triazol-1-yl)-ethanone

Four compounds have been synthesized and characterized by¹H NMR spectroscopy and elemental analyses, among which 1-(4,5-dihydro-3-phenyl-pyrazol-1-yl)-2-(1H-1,2,4-triazol-1-yl)ethanone 3a was further confirmed by X-ray crystallographic analysis. The biological activities of these compounds were tested, with the result that they displayed moderate fungicidal activities. In addition, a MO calculations using density functional theory (DFT) at B3LYP/6-31G^* level have also been carried out, and the structure–activity relationships for these compounds are discussed.     

Novel Schiff bases–based thiophenes: Design,synthesis and biological evaluation

2-amino-5-(3-fluoro-4-methoxyphenyl)thiophene-3-carbonitrile derivatives have been synthesized from 1-(3-fluoro-4-methoxyphenyl)ethanone, malononitrile, mild base, and sulfur powder using the Gewald method through a multistep reaction sequence. The structures of newly synthesized compounds were established on the basis of their elemental analyses, IR, ¹H NMR, ¹³C NMR, and mass spectral data, and then synthesized compounds were screened for their in vitro antimicrobial activity. Among them, derivatives 3b (thiphene), 3f (pyrazole), and 3d (halogen) showed good activity and remaining derivatives exhibited moderate activity.     

Synthesis of 1-trifluoroacetyl-3-dialkylamino-methyl-5-monosubstituted benzimidazoline-2-thiones using trifluoroacetic acid as an acylating agent

1-Trifluoroacetyl-3-dialkylaminomethyl-5-monosubstituted benzimidazoline-2-thiones have been synthesized from p-substituted anilines which were acetylated with trifluoroacetic acid. The trifluoroacetanilides were nitrated, reduced and cyclised with carbon disulphide in the presence of alcoholic potassium hydroxide and finally treated with formaldehyde and suitable secondary amines to afford the Mannich bases. The compounds were characterised by their analytical and spectral (ir, pmr, ¹⁹F and mass) data. The synthesized compounds have been screened for anti-inflammatory and analgesic activity and found to be active.     

3-取代苯氧甲基-4-氨基-1,2,4-三唑-5-硫酮席夫碱的合成、结构表征和生物活性研究

以醋酸为反应溶剂和催化剂,用自制的4-氨基-4,5-二氢-3-取代苯氧甲基-1,2,4-三唑-5-硫酮与4-氟苯甲醛反应合成了5个4-氨基-4,5-二氢-3-取代苯氧甲基-1,2,4-三唑-5-硫酮席夫碱化合物,通过1HNMR、IR和元素分析对所有化合物进行了结构表征.初步生物活性测试结果表明所有化合物具有优良的杀菌活性,并对席夫碱结构与活性的关系进行了探讨.     

Synthesis,spectroscopic study,X-ray diffraction,and comparative antimicrobial study of Schiff bases based on o-toluidine and their Co(II) complexes

Schiff bases are versatile compounds for the design of the ternary complex. An experiment has been made to synthesize two novel complexes of Co(II). Here, The primary ligand, L₁ was prepared by the condensation reaction of o-toluidine with 3-formyl chromone or o-toluidine with 3- methylquinolinecarbaldehyde and the secondary ligand which was 8-Hydroxyquinoline. These potent complexes were prepared by condensation of primary and secondary ligands with Cobalt salt. The reaction was performed through the conventional reflux method. The newly synthesized chromone and quinoline derived novel compounds are proposed to have significant antimicrobial activity against selective strains of bacteria and fungi. This can be great opportunity for researchers and the use of biological applications of the synthesized novel compounds can be a part of unique field of research for the future to be focus. Chromone derivative has great biological diversity in the medicinal and pharmaceutical fields. Along with these compounds, quinoline derivatives also have antibacterial, and antifungal activities. The synthesized ligand and complex were characterized by elemental analysis, molecular weight determination, magnetic moment measurement, melting point determination, spectral analysis (IR, UV–Vis, ¹H NMR, Mass, etc.), and X-ray diffraction. The synthesized complexes were paramagnetic and non-electrolytic in nature. The Uv–Vis, FTIR, NMR, and Mass spectra suggest the octahedral geometry of the complexes. The synthesized compounds were further evaluated for biological studies against selected bacterial and fungal strains. It has been observed that the antimicrobial activity of most of the complexes are better than that of ligands.     

Synthesis,characterization and antibacterial activity of some new pyrazole based Schiff bases

In the present study a series of new Schiff bases were synthesized. All the synthesized compounds were characterized by IR, ¹H NMR, mass spectral and elemental analyses. Newly synthesized compounds were screened for their antibacterial (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa) activity. The results revealed that, compounds 3f and 3c have exhibited significant biological activity against the tested microorganisms.     

Synthesis of 2-Azido-4-nitroimidazole and Its Derivatives for High-Energy Materials

2-Azido-4-nitroimidazole and its derivatives have been synthesized for energetic material applications. The synthesized compounds were fully characterized by 1H, 13C NMR spectroscopy and elemental analysis. Most of them were determined by single crystal X-ray diffraction. The calculated densities of the compounds range between 1.71 and 1.92 g,cm-3. The calculated detonation pressures （P） for these derivatives fall in the range of 25.17 to 32.62 GPa and the detonation velocities （D） are distributed from 7.65 to 8.55 km·s-1.     

Synthesis and antimicrobial activity of some 7‐aryl‐5,6‐dihydro‐14‐aza[1]benzopyrano[3,4‐b]phenanthren‐8H‐ones

The title compounds, 7‐aryl‐5,6‐dihydro‐14‐aza[1]benzopyrano[3,4‐b]phenanthren‐8H‐ones 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l have been synthesized by reacting various 4‐hydroxy coumarins 1a , 1b , 1c with 2‐arylidene‐1‐tetralones 2a , 2b , 2c , 2d in the presence of ammonium acetate and acetic acid under Krohnke's reaction condition. The structures of all the synthesized compounds were supported by analytical, IR, ¹H‐NMR, and ¹³C‐NMR data. All the synthesized compounds 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l have been screened for their antibacterial activities against Escherichia coli (Gram ?ve bacteria), Bacillus subtilis (Gram +ve bacteria), and antifungal activity against Candida albicans (Fungi). J. Heterocyclic Chem., (2011).