Synthesis and characterization of some conjugated ketoanilides and their metal complexes

The reaction between acetoacetanilide and aromatic aldehydes (2,4-dimethoxybenzaldehyde, veratraldehyde and piperonal) under specified conditions yielded two types of conjugated ketoanilides in which the keto-groups are attached to olefinic linkages. The existence of these compounds predominantly in the intramolecularly hydrogen-bonded enol form has been well demonstrated from their IR, ¹H NMR, and mass spectral data. Details on the formation of their complexes with Ni(II), Cu(II), and Zn(II) and their nature of bonding are discussed on the basis of analytical, IR, ¹H NMR, and mass spectral data. The text was submitted by the authors in English.     

Copper(II), nickel(II), palladium(II) and iron(III) complexes of 2-(3-phthalhydrazidylazo)-1,3-diketones

Neutral complexes of three phthalhydrazidylazo-1,3-diketones [phthalhydrazidylazo-acetylacetone (H₂PAA),-benzoylacetone (H₂PBA) and-dibenzoylmethane (H₂PDM)] with Cu(II), Ni(II), Pd(II) and Fe(III) have been synthesised and characterized on the basis of their analytical data, magnetic moment, molar conductance and IR and¹H NMR spectral data. Dibasic tridentate coordination of the ligands is brought out by the above spectral data. Half-wave potentials and far IR spectral data of the Cu(II) complexes indicate that the H₂PAA complex is the most stable. M?ssbauer spectra of the Fe(III) complexes reveal that delocalisation of the metald electrons with the chelate ring decreases with increasing capability of the pendant groups of the ring for cross conjugation.     

Unsaturated polycarbonyl compounds and their metal complexes

A new series of unsaturated polycarbonyl compounds in which the keto group attached to olefinic linkage has been synthesized by the reaction of acetoacetanilide and aromatic aldehydes under specified conditions. The existence of these compounds predominantly in the intramolecularly hydrogen bonded enol form has been well demonstrated from their IR, ¹H NMR and mass spectral data. Details on the formation of their complexes with Ni(II), Cu(II), and Zn(II) and their nature of bonding are discussed on the basis of analytical, IR, ¹H NMR and mass spectral data.     

New Copper（Ⅱ） and Nickel（Ⅱ） Complexes of 4-Morpholinoacetophenone Thiosemicarbazone： Structural, Electrochemical and Antimicrobial Studies

4-Morpholinoacetophenone thiosemicarbazone, MAPT, and its nickel（Ⅱ） and copper（Ⅱ） complexes have been prepared and characterized by elemental analysis, magnetic susceptibility, spectral methods （FT-IR, ^1H NMR） and cyclic voltammetry. Electrochemical behaviors of the complexes have been studied by cyclic voltammetry in DMF media showing metal centered reduction processes for both of them. The redox properties, nature of the electrode processes and the stability of the complexes were discussed. [Cu（MAPT）2]Cl2 complex shows Cu（Ⅱ）/Cu（Ⅰ） couple and quasi-reversible wave associated with the Cu（Ⅲ）/Cu（Ⅱ） process. The reduction/oxidation potential values depend on the structures of complexes. Also, the antimicrobial activities of these complexes were determined against S. aureus, E. coli and B. subtilis.     

Complexation of 4-amino-1,3 dimethyl-2,6 pyrimidine-dione derivatives with cobalt(II) and nickel(II) ions: synthesis,spectral, thermal and antimicrobial studies

Four heterocyclic Schiff-base ligands derived from condensation of 4-amino-1,3 dimethyl-2,6 pyrimidine-dione with 2-hydroxybenzaldehyde, 2-methoxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde and 4-(dimethylamino) benzaldehyde, (HL¹, L², HL³and L⁴), respectively, and their Co(II) and Ni(II) complexes have been prepared and characterized via elemental analysis, molar conductance, magnetic moment, thermal and XRPD analysis as well as spectral data (IR, ¹H-NMR, mass and solid reflectance). IR data reveal that the ligands are bidentate neutral ligands except HL¹, which is monobasic tridentate with coordination sites azomethine (N), carbonyl (O) and phenolic (O). Conductance data suggest that all complexes are non-electrolytes, except cobalt(II) complexes of L²and HL³are 1 : 1 electrolytes. The mass spectra confirm the proposed structure of the ligands and their complexes. The solid reflectance spectral data and magnetic moment measurements suggest octahedral, tetrahedral and square planar geometrical structures for the metal complexes. The spectral data were utilized to compute the important ligand field parameters B, β and Dq; LFSE also was calculated. The thermal behavior is also studied. Antibacterial and antifungal properties of the ligands and their complexes show broad-spectrum activities and the metal complexes show higher activity than the free ligands.     

Synthesis and antibacterial activity of novel series of 2‐(p‐tolyloxy)‐3‐(5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl)quinoline

A new series of 2‐(p‐tolyloxy)‐3‐(5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl)quinoline were synthesized from oxidative cyclization of N′‐((2‐(p‐tolyloxy)quinoline‐3‐yl)methylene)isonicotinohydrazide in DMSO/I₂ at reflux condition for 3–4 h. The structures of the new compounds were confirmed by elemental analyses as well as IR, ¹H‐NMR, and mass spectral data. All the synthesized compounds were screened for their antibacterial activities against various bacterial strains. Several of these compounds showed potential antibacterial activity. J. Heterocyclic Chem., (2011).     

Synthesis of 4-(4-Methylsulfonylphenyl)-3-phenyl-2(3H)-thiazole Thione Derivatives as New Potential COX-2 Inhibitors

Synthesis of novel 4-（4-methylsulfonylphenyl）-3-phenyl-2（3H）-thiazole thione derivatives with functionalized diarylheterocycle pharmacophore as potential COX-2 inhibitors was described. The title compounds were synthesized by cyclocondensation of corresponding dithiocarbamate and 2-bromo-1-（4-methylsulfonylphenyl）ethanone, followed by dehydration with H2SO4. All of the target compounds were characterized by ^1H NMR, IR and mass spectral data.     

Synthesis and characterization of substituted aminobiphenylglyoximes and their complexes with some transition metals

In this study, four different new vic-dioximates, [L¹H₂] N-(4-ethylphenyl)amino-biphenylglyoxime, [L²H₂] N-(4-butylphenyl)aminobiphenylglyoxime, [L³H₂] N-(4-aminoacetanilide)aminobiphenylglyoxime, and [L⁴H₂] N-(thiazol-2-yl-aminobiphenylglyoxime are synthesized from anti-4′-biphenylchloroglyoxime and the corresponding substituted aromatic amines. The Co(II), Ni(II), and Cu(II) complexes of these ligands are prepared. The structures of these new ligands and their complexes are proposed based upon IR, ¹H, and ¹³C NMR spectral data, mass spectroscopy, magnetic susceptibility measurement, and elemental analyses. The text was submitted by the authors in English.     

Synthesis and Structure of Tetrahydro-4,7-ethanoisobenzofuran-1,3-dione Derivative

(1R,2R,3S,4R,7R)‐7‐Isopropyl‐6‐methylbicyclo[2.2.2]oct‐5‐ene‐2,3‐dicarboxylic acid anhydride (tetrahydro‐4,7‐ethanoisobenzofuran‐1,3‐dione derivative) adduct 2 was prepared via the isomerization of α‐pinene and β‐pinene in turpentine followed by the Diels‐Alder cycloaddition with maleic anhydride in the presence of phosphoric acid/iodine catalysis. The molecular structure of adduct 2 was characterized by IR, ¹H NMR, ¹³C NMR, ¹H‐¹H COSY, DEPT, HSQC, HMBC, 2D NOESY and MS spectra. The single crystal X‐ray crystallographic analysis of adduct 2 was performed, and the X‐ray powder diffractive spectrum of the sample adduct 2 is consistent with the diffractive spectrum calculated from the single crystal data. Therefore the structure and stereochemistry of adduct 2 was established based on extensive spectral data and single crystal X‐ray analysis.     

Efficient,Convenient and Mild Three‐Component Template Preparation and Characterization of Some New Schiff Base Complexes

A few kinds of novel Schiff base complexes have been prepared by three‐component reaction of the substituted hydroxyacetophenone with several aliphatic diamines and transition metals such as; Cu(II), Co(II), Mn(II), Zn(II) and UO₂(II) under mild reaction conditions. The products have been afforded with excellent yields and appropriate reaction times. The structures of these ligands have been characterized by their IR, ¹H NMR, ¹³C NMR and MS spectral and physical data.     

Polymer complexes,part XXI. Stereochemical changes of metal chelates of poly(5-vinylsalicylidene-2-benzothiazoline)

Summary Poly(5-vinylsalicylidene-2-benzothiazoline) homopolymer (PVSBH₂) and polymer complexes of 5-vinylsalicylidene-2-benzothiazoline with a number of divalent transition metals have been prepared and characterized using spectral (¹H NMR and¹³C-NMR, IR, UV-VIS) and magnetic measurements. The data suggest that the Co(II), Ni(II), Fe(II) and Mn(II) polymer complexes are octahedral dimers, while the rest are monomeric with square planar tetrahedral geometries.

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Polymere Komplexe, 21. Mitt.: Stereochemische Änderungen in Metallchelaten von Poly(5-vinylsalicyliden-2-benzothiazolinen)

Zusammenfassung Es wurden homopolymere Poly(5-vinylsalicyliden-2-benzothiazolin)-(PVSBH₂) und polymere 5-Vinylsalicyliden-2-benzothiazolin-Komplexe mit einer Reihe von zweiwertigen Metallen hergestellt und mittels spektroskopischer (¹H- und¹³C-NMR, IR, UV-VIS) und magnetischer Messungen charakterisiert. Die Daten erlauben den Schluß, daß es sich bei den Co(II)-, Ni(II)-, Fe(II)- und Mn(II)-Polymerkomplexen um oktahedrale Dimere handelt, während der Rest monomere Strukturen mit planar-tetrahedraler Geometrie zeigt.

     

Synthesis of 2‐amino‐4‐(2‐ethoxybenzo[d][1,3]dioxol‐5‐yl)‐4H‐pyran‐3‐Carbonitrile Derivatives and Their Biological Evaluation

A new class of substituted 2‐amino‐4‐(2‐ethoxybenzo[d][1,3]dioxol‐5‐yl)‐4H‐pyran‐3‐carbonitrile derivatives catalyzed by Imidazole under mild reaction conditions has been developed. A variety of functionalized 2‐amino‐4‐(2‐ethoxybenzo[d][1,3]dioxol‐5‐yl)‐4H‐pyran‐3‐carbonitrile scaffolds were assembled in high yields by this catalytic protocol. The newly synthesized compounds have been characterized by IR, ¹H NMR, ¹³C NMR, and mass spectral data. The compounds were then evaluated for antimicrobial activities.     

Synthesis,spectroscopic, antibacterial and antifungal studies of nickel(II)5(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolinates and their addition complexes with N and P donor ligands

A number of complexes of nickel(II) with 5(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolines of the type (C₁₅H₁₂N₂O ··· X)₂Ni [where X = H, Cl, CH₃ and OCH₃] were synthesized by the reaction of anhydrous nickel(II) chloride with sodium salts of pyrazoline in 1 : 2 molar ratio. Their addition complexes with 2,2′-bipyridine, 1,10-phenanthroline and triphenylphosphine were prepared in 1 : 1 molar ratio. These complexes were characterized by elemental analyses, molecular weight, magnetic, conductivity, IR, electronic, ¹H, ¹³C, ³¹P NMR and FAB mass spectral data. All complexes are amorphous. Square planar geometry around nickel confirms the presence of two bidentate pyrazoline ligands in nickel(II)5(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolinates. In the addition complexes pyrazoline is monodentate. Bidentate and monodentate pyrazoline was confirmed by IR, ¹H, ¹³C and ³¹P NMR spectral data. All the metal complexes exhibit very good antibacterial and antifungal activity. Coordination of metal ion has pronounced effect on the microbial activities of the ligand. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties; all complexes and adducts display potent cytotoxic activity against Artemia salina.     

Efficient,Convenient and Mild Three Component Template Preparation and Characterization of Some New Schiff Base Complexes

A few kinds of novel Schiff base complexes have been prepared by three component reaction of the substituted hydroxyacetophenone with several aliphatic diamines and transition metals such as; Ni(II), Zn(II) and UO₂(II) under mild reaction conditions. The products have been afforded with excellent yields and appropriate reaction times. The structure of these ligands has been characterized by their IR, ¹H NMR, ¹³C NMR and MS spectral and physical data.     

The synthesis and characterization of three new vic -dioximes and their nickel(II), copper(II) and cobalt(II) complexes

Three new vic-dioximes, [L¹H₂], N-(4-ethylphenyl)amino-1-acetyl-1-cyclohexenylglyoxime, [L²H₂], N-(4-butylphenyl)amino-1-acetyl-1-cyclohexenylglyoxime, and [L³H₂], N-(4-methoxyphenyl)amino-1-acetyl-1-cyclohexenylglyoxime were synthesized from 1-acetyl-1-cyclohexeneglyoxime and the corresponding substituted aromatic amines. Metal complexes of these ligands were also synthesized with Ni(II), Cu(II), and Co(II) salts. These new compounds (ligands and complexes) were characterized with FT–IR, magnetic susceptibility measurement, molar conductivity measurements, mass spectrometry measurements, thermal methods (e.g. thermal gravimetric analysis), ¹H NMR (Nuclear Magnetic Resonance) and ¹³C NMR spectral data and elemental analyses.     

Zinc(II) 5-(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolinates and their adducts with N and P donor ligands: synthesis,spectral, biological,and anti-inflammatory investigations

Synthesis, spectral, biological, and anti-inflammatory investigations of a series of complexes of zinc(II) with 5-(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolines of the type (C₁₅H₁₂N₂OX)₂Zn (where X =–H,–Cl,–CH₃,–OCH₃) are presented. The complexes were synthesized by reaction of anhydrous zinc(II) chloride with sodium salts of pyrazoline in 1 : 2 molar ratio. Adducts with N and P donor ligands (2,2′-bipyridine, 1,10-phenanthroline and triphenylphosphine) were prepared in 1 : 1 molar ratio. The complexes were characterized by elemental analyses, molecular weight, conductivity, IR, electronic, ¹H, ¹³C, ³¹P NMR, and FAB mass spectral studies. All complexes are amorphous. Tetrahedral geometry around zinc confirms the presence of two bidentate pyrazoline ligands in zinc(II) 5-(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolinates. In adducts pyrazoline is monodentate. Bidentate and monodentate pyrazoline were confirmed by IR, ¹H, ¹³C, and ³¹P NMR spectral data. All metal complexes were tested for their antibacterial and antifungal activities. Anti-inflammatory activity was also carried out by the carrageenan-induced rat paw edema test. Brine shrimp bioassay was also carried out to study in-vitro cytotoxic properties.     

A New Cyclopropyl‐Triterpenoid from Ochradenus arabicus

One new cyclopropyl‐triterpenoid ( 1 ), along with four known constituents including octacosan‐1‐ol ( 2 ), pentacosanoic acid ( 3 ), β‐sitosterol ( 4 ), and β‐sitosterol 3‐O‐β‐D ‐glucopyranoside ( 5 ) were isolated from the aerial parts of Ochradenus arabicus for the first time. These compounds were isolated by repeated column chromatography followed by further purification through recycling HPLC. The structure of the new secondary metabolite 1 was established on the basis of UV, IR, 1D‐ (¹H‐ and ¹³C‐) and 2D‐NMR (HMBC and HSQC), and MS spectral data. The molecular mass was determined by HR‐MS, and hence the molecular formula was deduced. The configurations of stereogenic centers in the molecule were assigned by NOESY experiments, along with biogenetic considerations. The structures of the known compounds were confirmed by comparison of their physical and spectroscopic data with those reported in literature.     

One Pot Photoredox Decarboxylation Reaction of N‐Cyano(α‐bromo‐α‐phenyl)methylanilines Leading to Synthesis of Four‐Membered Cyclic Carbamates

A new four‐membered cyclic carbamates have been synthesized through solar irradiation of N‐cyano(α‐bromo‐α‐phenyl)methylanilines in their aqueous methanolic solution using iodide salt in basic medium. These compounds have been characterized as 3,4‐diphenyl‐1,3oxazetidin‐2‐one through their elemental analysis, IR, ¹H‐NMR, ¹³C‐NMR, and mass spectral studies.     

Transition metal complexes of 1,2‐dihydroquinazolinone derivative,an emerging class of analgesic and anti‐inflammatory agents

A new 1,2‐dihydroquinazolinone, 2‐(2‐hydroxy‐phenyl)‐3‐[1‐(2‐oxo‐2H‐chromen‐3‐yl)‐ethylideneamino]‐2,3‐dihydro‐1H‐quinazolin‐4‐one (L) and its Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been prepared. These were characterized by elemental, spectral [UV–visible, IR, NMR (¹H, ¹³C and 2D heteronuclear correlation) and mass], conductance, magnetic susceptibility and thermal studies. The physicochemical data indicate that the ligand behaves as tridentate with ONO donor sequence towards the metal ions, and trigonal bipyramidal geometry was assigned for complexes. The ligand and its metal complexes were evaluated for their in vivo anti‐inflammatory and analgesic activity. The tested compounds have shown excellent activity, which are almost equipotent to the standard used in the study. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis and spectral characterization of some binuclear complexes designed from N4O and N2O3 donor Schiff-base ligands of 2,6-diformyl-4-methylphenol

New pentadentate binucleating ligands containing phenoxide as an endogenous bridging group, 2,6-diformyl-4-methylphenol bis(carbohydrazone) (L¹H), and 2,6-diformyl-4-methylphenol bis(semicarbazone) (L²H), and their binuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes of general formula [M₂LCl₃] · nH₂O with chloride as an exogenous bridge have been synthesized. The complexes were characterized on the basis of elemental analysis, conductivity measurements, thermal analysis, IR, Far-IR, NMR, UV–Vis, EPR, FAB-mass and magnetic data. The coordination mode (N₄O, N₂O₃), as well as endogenous phenoxide bridge and an exogenous chloride bridge have been established on the basis of IR, Far-IR and ¹H-NMR spectral data. Electronic spectral data of the complexes indicate square-pyramidal geometry. EPR spectra show line broadening, which is further supported by weak antiferromagnetic interaction from the room temperature magnetic moment data. All compounds show appreciable antimicrobial activity.