Synthesis and Antibacterial Activity of New Cephalosporin Compounds

The fourth generation cephalosporin cefepime I exhibited potent antibacterial activity with board antibacterial spectrum1,2.Based on the structure of cefepime,we synthesized its analogs Ia having fluoro atom at the aminothiazolyl oxime moiety at the7-position of the cephem nucleus,and Ib possessing1-(2-fluoroethyl)pyrrolidium methyl group at the3-position.It was reported that cephalosporin derivatives with a quaternary ammonium moiety at the3-position of the cephem nucleus,showed enhanced ant…     

Molecular recognition studies on supramolecular systems (XXIV)——Conformations and complexation abilities of chemically modified cyclodextrins in aqueous solution

Circular dichroism spectral and fluorescence decay methods have been employed to determine the conformations of mono[6-(p-tolylseleno)-6-deoxy]-p-CD(1), mono(6-anilino-6-deoxy) β -CD (2) and mono[6-(L-tryptophan)-6-deoxy]-β-CD (3) in phosphate buffer solution (pH 7.2, 0.1 mol dm-3) at 298.15 K. The results indicate that compounds 2 and 3 formed self-inclusion complexes in aqueous buffer solution, while the substituent of compound 1 was not included into cyclodextrin cavity at all. Furthermore, the complex stability constant (logKs) and Gibbs free energy change (-ΔG° ) of these three cylcodextrin derivatives with several cycloalkanols have been determined by circular dichroism spectral titration in phosphate buffer solution at 298.15 K. It is found that the location of the substituent affects the stability of host-guest complex in aqueous solution.     

Influence of the Substituents on Imino-aryl Ring of Mono(imino)pyrrole-Ni~(Ⅱ) Complexes to Their Ethylene Polymerization Catalytic Performance

In order to study the influence of substituents on imino-aryl rings of mono(imino)pyrrole-transition metal complexes to their ethylene polymerization performance, a series of mono(imine)pyrroles(L1-L3) were synthesized by microwave irradiation from 2-acetylpyrrole and a series of 2,6-position disubstituted anilines(substituent: H, Me, Et). A simplified synthetic method was introduced to prepare the corresponding nickel complexes NiL_2(1～3) with direct condensation of mono(imine)pyrrole ligands and nickel dichloride. All the compounds were fully characterized by 1 H NMR, IR, EA, MS, and X-ray crystal diffraction. Ligand L3(C_(16)H_(20)N_2, Mr = 240.34) belongs to the triclinic system, space group P1, with a = 7.9606(19), b = 9.028(2), c = 11.205(3) ?, the final R = 0.0606 and wR = 0.1875. Complex 3(C_(32)H_(38)N_4Ni, Mr = 537.37) belongs to the monoclinic system, space group C2/c with a = 19.811(3), b = 11.262(2), c = 26.004(4) ?, the final R = 0.0388 and wR = 0.1020. The crystal structures indicated that all the Ni~(Ⅱ) complexes have similar tetra-coordinated geometries, in which the ligand chelated to the center nickel with a 2:1 molar ratio. Catalytic properties of the Ni~(Ⅱ) complexes for ethylene polymerization were systematically investigated, and the results showed a regular increase of catalytic activities with steric hindrance of the substituents on the imino-aryl ring of Ni~(Ⅱ) complexes.     

Synthesis, Crystal Structure and Photoluminescent Property of a Novel Disilver Complex with Pyrazinyl Oxime Ligand

<正>A novel binuclear Ag(I) complex [Ag_2(C_6H_6N_3O)_2(C_6H_7N_3O)_2]·2CH_3CN (1) was synthesized by the evaporation reaction of silver nitrate and (E)-1-(pyrazin-2-yl)ethanone oxime (HL). The complex was characterized by elemental analysis, IR spectrum and X-ray single-crystal diffraction analysis. It crystallizes in the monoclinic space group C2/c with a = 22.7089(3), b = 11.5443(7), c = 16.1468(4) , β = 127.7150(10)°, V = 3348.6(2) ~3, D_c = 1.675 g/cm~3, M_r = 844.42, Z = 4, F(000) = 1696.0, μ = 1.226 mm~(-1), the final R =0.0250 and wR = 0.070. The coordination around the silver(I) atom is a distorted trigonal-bipyramidal geometry involving one protonated pyrazinyl oxime ligand (HL), one deprotonated oxime ligand (L~-) and one CH_3CN solvate molecule in the asymmetric unit of complex 1.     

Synthesis and Characterization of β—Cyclodextrin Bonded Metal Porphyrins

Reactions of 5-(p-aminophenyl)-10,15,20-triphenyl porphyrin (1) with Ru3(CO)12 or M(OCOCH3)2 (M=Ni,Mn) afforded metalloporphyrins(4-6),respectively.6-Deoxy-6-io-do-β-cyclodextrin(2) and mono(6-O-trifluoromethanesulfonyl) permethylated β-cyclodextrin(3) reacted with complexes 4-6 to give β-cyclodextrin bonded metal porphyrins (7-9) and permethylated β-cyclodextrin bonded me-tal porphyrins (10-12) respectively.These new complexes were identified by MS,IR,UV-visible and ^1H NMR spectra,and elemental analysis.     

Behavior and Quantification Studies of Phoxim Pesticide Using Cyclic and Linear Sweep Stripping Voltammetry at a Mercury Electrode

Phoxim, benzoyl cyanide-O-(diethoxyphosphinothioyl)oxime, is an organophosphorusinsecticide of moderate to low mammalian toxicity. Phoxim was individuallydetermined in fruit and vegetable samples, utilizing chromatography1 and single sweeppolarography2.Ex…     

Catalytic Cleavage of Phosphate by Modified Polyethylenimines (Ⅱ)

A series of modified polyethylenimines (PEIs) containing oxime groups and cetyl groups were prepared. The dissociated constants of oxime group and the rate constants of its reaction with p-nitrophenyl diphenyl phosphate (PNPDPP) were determined. These polymers are good catalysts for the cleavage of PNPDPP under aqueous conditions. Rate accelerations approach 10~4-10~5-fold level with turnover behavior. Reaction mechanism is analogous to that of enzyme-catalyzed kinetics.     

Synthesis and Structure of Bis（indene—1,2,3—trione 2—oximato）bis （aqua）Mn（Ⅱ）：Mn（C9H4NO3）2（H2O）2

1 INTRODUCTION The interest in the complexes of transition metals with ligands ketoxime[1, 2] as potential models for metal binding sites in ferroverdin[3, 4] has prompted the investigation on the structures and the overall coordination geometry of the metal centers in these complexes. Oxime derivatives are interesting ligands since the ketoximes are found to chelate transition metals through the N (oxime) and O (ketone) atoms[5, 6]. However, monodentate coordination via only one O or …     

A New Hapten for Immunoassay of Aldicarb

Aldicarb, 2-methyl-2-(methylthio)propionaldehyde O-(methylcarbamoyl)oxime, is a systemic N-methylcarbamate insecticide and has been used on a variety of crops. It is moderately water soluble and considered as one of the most acutely toxic pesiticides. Ald…     

Liquid Phase Hydration of FCC C4 Mixtures Catalyzed by Zeolite Catalysts

Methyltert butylether (MTBE)asanoctanepromoterinautomobilefuelshasbeenphasedoutinsomecountriesduetoenvironmentalproblems .Thismotivatessubstantialinterestinfindingnewwaysforupgradinggasoline[1,2 ] .TheuseofareplacementforMTBE ,suchasethanol,isafeasiblemethodtoen hancetheoxygenatesandincreasetheoctanenumberofgasoline[3 ] .However ,ethanoldoesnotmixwellwithgasolinebecauseofitstendencytoseparatefromthefuelinthepresenceofwater ,andasolventtoim provethesolubilityofethanolinthefuelmustbeadded .B…     

Synthesis of Fluoroalkylated Heterocycles via the Reaction of 3-(1-Hydropolyfluoroalkenyl)-1-oxo-2,4,1-benzoxazines with Dinucleophilic Reagents

The reaction of 3-(1-hydropolyfluoroalkenyl)-1-oxo-2,4,1-benzoxazines 1 with some dinucleophiles was inves-tigated.7-Fluoroalkyl-2,3-dihydro-1,4-diazepine[1,2-d]quinazolin-11-ones 2,2-fluoroalkylisoxazolo[3,2-b]quin-azolin-9-ones 3 and 2-fluoroalkylbenzoimidazoles 4 were obtained from the reaction of 1 with 1,2-diaminoethane,hydroxylamine hydrochloride and 1,2-diaminobenzene respectively.     

Synthesis of 1,2,3,4-Tetrahydro-1-Indolizinones and 3-Methyl-1,2-dihydro-1-Pyrrolizinones

lthasbeenrePortedthat1,2dihydro-1-pyrmIizinone(1)andsomeofitsderivativesshowedsignificantanaIgesicandantiinnammatory.Cti.iti..ll1.Theketonewassynthesizedfrom3(1-pyrmIyI)propanenitriIe(2)byanimprovedHoesCh'sprocedure.lnoedertostudythestruCture-aCtivityreIationshipdeepIy,theanaIogueoftheketone,1,2,3,4-tetrahydro-1-indolizinone(3)andsomeofitsderivativesweredesignedandsynthesized.ComPOund3wnsfirstsynthesizedbyG.R.CIemoet.aI.withHoeSChreaCtionfrom4-(1-pyrrolyI)bUtanenitriIe(4)m.ThenitriI…     

Facile Synthesis of Amidines via Intermolecular Reductive Coupling of Nitriles with Azobenzene Promoted by Samarium Diiodide

SinceintroducedbyKaganandhisgroups',Sml,hasbeenextensivelyinvestigatedasamild,neutral,selectiveandversatilesingIeelectrontransferreductantinsyntheticchemistry=.Suchas,Barbierreactions,Reformatskyreactions,pinacolcouplingandketone-oIefinreductivehavebeenreportedusingSmI,asreagent.Thereactivitiesofvariousnitrogenfunctionalgroups(imine,oxime,nitro,azo,cyano)towardsSmI,havealsobeenexamined.Recently,ourgrouphasreportedtheintermolecularreductivecouplingofnitrogroupswithcyanogroupsinducedbySml='.…     

The Effect of Platinum on Stability of the B2O3/TiO2-ZrO2 Catalyst for Beckmann Rearrangement of Cyclohexanone Oxime

It has been well illustrated that the rapid catalyst deactivation with time is the most serious limitation of vapor phase approach to the production of ε-caprolactam from cyclohexanone oxime (CHO) (Scheme 1), and is a common problem with all catalyst typ…     

硫酸介质中控制碳钢腐蚀的烷基取代Piperidin-4-one Oximes的立体效应

Three synthesized piperidin-4-one oximes,3-ethyl-2,6-diphenyl-piperidin-4-one oxime(A),1-methyl-3-isopropyl-2,6-diphenyl-piperidin-4-one oxime(B),and 3-isopropyl-2,6-diphenyl-piperidin-4-one oxime(C),were tested at different concentrations to determine their ability to inhibit corrosion of mild steel in 1 mol.L-1 H2SO4 and measured by a mass loss method(at various temperatures),polarization and impedance measurements,X-ray diffraction(XRD),scanning electron microscopy(SEM) with energy-dispersive X-ray spectroscopy(EDS),and a quantum chemical method.The synergistic influence of compounds A,B and C with iodides has also been evaluated.All three compounds show good inhibition efficiency in the following order:A>B>C.Compounds A,B and C were found to physically adsorb on the surface of mild steel while obeying the Temkin isotherm.Polarization measurements indicated that these compounds behave as a mixed mode inhibitor.XRD and SEM with EDS studies revealed the formation of a protective barrier on the mild steel surface by these oximes.The electron donating ability of the studied molecules was tested using semi empirical methods.The studies revealed that the oxime nitrogen,the piperidine moiety,and the phenyl ring assist largely in corrosion control.The studies also showed that the steric crowding by the alkyl group in the piperidine ring affects the inhibitor efficiency.Further,it is interesting to note that all of the studied compounds exhibit synergism with iodide ions.     

Synthesis and reactions of some 6-aryl and 2,6-diaryl-4-(4''''-antipyrinyl)-2,3,4,5-tetrahydropyridasin-3-ones and screening for their antibacterial activities

Some new pyridazinone derivatives(3) were synthesized through addition of antipyrin to β-aroylacrylic acids (1) followed by cyclization of the adducts. Reactions of 3 with ethyl bromoacetate,benzenesulfonyl chloride, benzoyl chloride and POCl_3 give N-substituted products and monochlorosub-stituted pyridazines (4), respectively. The reactions of the latter with thiourea give unexpected dithio-derivatives(5), which react with phenylhydrazine to give pyrazolopyridazino pyridazine derivatives (6).Reactions of 2 with NH_2OH in ethanol and pyridine afford oxime and oxazinone derivatives 7 and 8,tespectively. The antibacterial activities of several compounds were screened.     

Synthesis, Crystal Structure and Properties of Complex VO（C10H9NO3） （C13H10NO2）

Complex VO(C10H9NO3)(C13H10NO2)(C10H9NO2-3=N-salicylidene-L-alaninate, C13H10NO-2=N-phenylbenzohydroxamate) was synthesized and characterized by means of elemental analysis, IR, UV, 1H NMR spectroscopies, cyclic voltammetry and single crystal X-ray diffraction. The complex crystallized in a monoclinic system with space group P21 and crystal cell parameters a=0.9720(1) nm, b=1.8274(2) nm, c=1.2542(1) nm, β=104.868(9)°, V=2.1532(4) nm3, Mr=470.34, Z=2. The two oxygen atoms and the one nitrogen atom of the tridentate Schiff base ligand and the one oxime oxygen atom of the hydroxamate ligand coordinate to the vanadium atom, forming an equatorial plane, the two axial positions are respectively occupied by the oxygen atom of the oxovanadium and the carbonyl oxygen atom of the hydroxamate and the vanadium atom exhibits a distorted octahedral VO(ONO)(OO) coordination sphere. The 1H NMR spectrum suggests that the two isomers, endo and exo in a molar ratio of 1/1.7, coexist in the solution of the title complex in CDCl3. There exists a quasi-reversible one-electron redox reaction corresponding to VⅤ/VⅥ couple in the three non-aqueous solvents, and the redox potential E1/2 of the title complex substantially shifts in the direction of the positive voltage increase in the order: CH2Cl2＜CH3CN＜DMF.     

Synthesis and Crystal Structure of Cluster [C6H4-1,2-(CO2CH2C2H-μ)2][Co2(CO)6]2

The reaction of dipropargyl phthalate C6H4-1,2-(CO2CH2C2H-μ)2 1 with octacarbonyldicobalt 2 resulted in the formation of red complex [C6H4-1,2-(CO2CH2C2H-μ)2][Co2(CO)6]2 3, in which each Co2(CO)6 group coordinates to one of the two C≡C bonds of 1. Molecular structure of complex 3 was determined by single crystal X-ray analyses. The crystal belongs to the monoclinic system, space group P21/a with the following crystallographic parameters: a=8.521(2), b=29.143(6), c=12.918(7)(A), β= 100.12(3)°, V=3158(2)(A)3, Z=4, Mr=814.09, Dc=1.712 g.cm-3, F(000)=1608, μ(Mo-Kα)=21.37 cm-1 and final R=0.044 for 3151 observations.     

Studies of Electrochemical Catalytic Reduction Reactions of Tetraphenylporphinatocobalt/1,2-Dibromoethane and 1,2-Dichloroethane Systems in Nonaqueous Media

Electrochemical catalytic reactions of tetraphenylporphmatocobalt were studied in DMF and EtCl2 solutions in the presence of 1,2 dibroraoethane and 1,2-dichloroethane utilizing cyclic voltamme-try, thin-layer electrochemistry, in situ UV-visible spectroelectrochemistry and computer digital simulation methods. Homogeneous rate constants for reactions of electrogenerated Co(Ⅰ)TPP species with 1,2-dibro-moethane and 1,2-dichloroethane were determined as 1. 2×103 and 5 mol-1 · dm3 × s-1, respectively. Neither alkylation nor degradation of CoTPP was observed.     

2—羟基—5—（1—甲庚基）苯甲醛肟萃取铜的性能

Comparative studies on the extraction of Cu(Ⅱ) have been performed by 2-hydroxy-5-(1-methylheptyl) benzaldoxime (N-590) without or with n-dodecanol as modifier, 2-hydroxy-5- (1-metylheptyl) benzophenone oxime (N-510), and 2-hydroxy-4-(1-methylheptyloxy) ben-zophenone oxime (N-530). When the extraction is carried out in feed liquor containing Cu1.03 g/L and Fe 10.7 g/L by 0. 1 mol·dm~(-3) extractant in kerosene, the Cu percentage extrac- tion of 95.6, 89 and 63%, and Cu(Ⅱ)-Fe(Ⅲ) separation factor of 1.46×10~3, 4.76×10~2and 1.26×10~2 are obtained with N-590, N-530 and N-510, respectively; moreover the Cuextraction and stripping speed with N-590 is greatly higher than that with N-530 and N-510. Addition of 2% n-dodecanol into 0.1 mol·dm~(-3) N-590 in kerosene improved the strip-ping behaviour.