Benzoin Oxime Research Articles

Synthesis, Characterization and Biological Activity of Some Mixed Ligand Transitionmetal Complexes

The Schiff bases derived from Salicylaldehyde with substituted amines and alpha benzoin oxime as a primary ligand are prepared by mixed with Cobalt (II), Nickel(II) and Copper (II). Structure have been proposed from elemental examination, like IR, NMR, thermal examination and magnetic susceptibility, Spectroscopic studies suggests that coordination occurs through azomethine nitrogen, hydroxyl group and oxime of the ligand to the metal ions. Elemental analysis of Schiff bases, alpha benzoin oxime and metal complexes are confirmed to stoichiometry of the type ML1L2 where Metals are Cobalt (II) andNickel (II) L1 are Schiff bases and L2 are alpha benzoin oxime. The mixed ligand Co(II) complexes were synthesize by using α-benzoin oxime as a primary ligand and Schiff base prepared from salicylaldehyde and chloroanilines with hydroxyanilines as a secondary ligand. The metal complexes have been characterized different elemental analyses and various chemical techniques such as molar conductance, magnetic susceptibility, infrared, NMR, spectral studies and thermal analysis. The elemental analysis data is consistent with their general formulation as mixed ligand complexes MLL’.xH2O. The bondings and structures of the complexes are discussed in detail on the basis of the results of various chemical studies. All of these metal complexes and ligands have been screened for their biological activities against selected pathogenic microbial strains. The Ditch Plate Method has been used to study the antibacterial activity against E. coli, S. typhi, S. aureusandS. pyogenes.

Recyclable Cu(II)-(MAA-EGDMA) catalyst for selective oxidation of alcohols to aldehydes using sodium hypochlorite

Copper(II) α-benzoin oxime complex was synthesized by the reaction between copper(II) benzoate and α-benzoin oxime. The poly methacrylic acid-ethylene glycol dimethacrylate (MAA-EGDMA) was applied as support of copper complex catalyst for oxidation of alcohols to aldehydes using NaClO. The structure and morphology of immobilized Cu(II)-benzoin oxime have been studied by using different analysis including Fourier Transform Infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) and Thermal Gravimetric Analysis (TGA). The yield of aldehydes was determined by Gas Chromatography (GC) analysis. The immobilized Cu(II)-benzoin oxime indicated a high catalytic activity compared to its absence for the alcohol oxidation with sodium hypochlorite. The effect of the reaction time and temperature, the solvent type, the amounts of catalyst and NaClO were optimized to obtain maximum yield. The prepared catalyst had various benefits such as being inexpensive, environmentally friendly manner, recyclable, reducing the reaction time and increasing the yield. A reaction mechanism is proposed for oxidation of alcohols in the presence of the catalyst.

Sensitive spectrophotometric determination of Co(II) using dispersive liquid-liquid micro-extraction method in soil samples.

Analytical performance of conventional spectrophotometer was developed by coupling of effective dispersive liquid-liquid micro-extraction method with spectrophotometric determination for ultra-trace determination of cobalt. The method was based on the formation of Co(II)-alpha-benzoin oxime complex and its extraction using a dispersive liquid-liquid micro-extraction technique. During the present work, several important variables such as pH, ligand concentration, amount and type of dispersive, and extracting solvent were optimized. It was found that the crucial factor for the Co(II)-alpha benzoin oxime complex formation is the pH of the alkaline alcoholic medium. Under the optimized condition, the calibration graph was linear in the ranges of 1.0-110 μg L(-1) with the detection limit (S/N = 3) of 0.5 μg L(-1). The preconcentration operation of 25 mL of sample gave enhancement factor of 75. The proposed method was applied for determination of Co(II) in soil samples.

English

The laccase producing fungus HC1 was isolated from a sample collected in the Bolivian Amazon region. Analysis of 5.8S and 28S rDNA, and internal transcribed spacer 1 and 2 sequences revealed that isolate HC1 belongs to genus Galerina. High production of laccase was achieved in basal salt medium supplemented with 30 g L-1 glucose, 10 g L-1 yeast extract and 0.01 g L-1 copper sulphate. The enzyme production was further improved by addition of 2,5-xylidine, α-benzoin oxime and p-coumaric acid, but strongly repressed by sinapyl alcohol, 3-(dimethylamino)benzoic acid, hydroquinone, 1-naphthale-neacetic acid, 2,6-dichlorophenol and 3-methyl-2-benzothiazolinone hydrazone. Cultivation under optimum conditions in the presence of 2 mmol L-1 2,5-xylidine and 0.01 g L-1 copper sulphate, resulted in the enzyme yield of over 26 000 U L-1. Galerina sp. HC1 could also produce laccase in media composed of orange peels both in submerged- and solid-state fermentations. The laccase (0.5 U ml-1) from Galerina sp. was able to decolorize over 60% of 35 μmol L-1 Congo red in 2 h in the presence of 2,2-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt as mediator, and 65% of 30 µmol L-1 Coomassie Brilliant Blue G-250 in 5 min using syringaldehyde as mediator. The laccase was immobilized on cross-linked chitosan and used efficiently to decolorize the dyes.   Key words: Oxidase, inducer, immobilized enzyme, enzyme production, solid-state cultivation.

Green Synthesis ofα-Benzoin Oxime, and the Selective Control and Separation of ItsCis-TransIsomers

报道了一种a-苯偶姻肟的合成及其顺、反异构体的分离方法．以苯甲醛为原料，双正离子咪唑盐为催化剂，通过氮杂卡宾机理合成了中间体a-苯偶姻，该方法条件温和，成本较低，环境友好，收率较高．在a-苯偶姻肟化生成a-苯偶姻肟的反应中，通过调节反应温度，得到了互为顺、反异构体的两种初产物，并采用梯度淋洗的柱层析法将两种异构体完全分离．

Solvent extraction studies on the complexation of palladium with alpha benzoin oxime

For the recovery of palladium from high level liquid waste (HLLW) a rapid and selective method of separation of palladium have been developed using alpha benzoin oxime (ABO) in Solvesso 100 in our laboratory. In continuation of this work, a detailed study is presented to determine the empirical formula (composition) of the palladium-alpha benzoin oxime (Pd-ABO) complex formed during solvent extraction with ABO in Solvesso 100. Both, the molar ratio method and the isomolar series method extended to two phase system are followed to establish the empirical formula of the Pd-ABO complex. The ligand to metal ratio is computed by analyzing the palladium concentration in the organic phase by direct spectrometry, by analysis of the aqueous phase using Arsenazo-III and also by using the 109Pd tracer technique. Degree of dissociation and apparent instability constant of the Pd-ABO complex are reported.

Synthesis and characterization of [2‐3H] (1R,2S)‐ (−)‐2‐amino‐1,2‐diphenylethanol

Abstract(R)‐(−) Benzoin oxime 2 was catalytically tritiated to afford [2‐3H] (1R,2S)‐(−)‐2‐amino‐1,2‐diphenylethanol 1 in 92% ee. Copyright © 2001 John Wiley & Sons, Ltd.

Comparative study of organic inhibitors of coppercorrosion

The corrosion behaviour of copper in the presence of two organic inhibitors that belongto the oxime group (salycilaldoxime (SO) and benzoinoxime (BO)) has been investigated inneutral aqueous NaCl solutions. Weight-loss measurements and electrochemical impedancespectroscopy (EIS) were applied to analyse the effect of the organic compounds on the corrosioninhibition of copper. Morphology of the copper substrate after corrosion in the presence andabsence of the inhibitors was examined using scanning electron microscopy (SEM). Fouriertransform infrared (FTIR) and X-ray photoelectron (XPS) spectroscopies were used tocharacterise the surface film. A polymeric Cu (II)-inhibitor complex that totally covered thecopper surface was identified, exhibiting strong corrosion inhibition. In the first stage, copperoxides are formed adhering to the metallic surface. The inhibitory mechanism on the Cudissolution process was related to both the chelating effect of Cu (II)ions close to the coppersurface, which avoids the action of aggressive Cl− or OH− ions in solution, and the blockingaction of the organic complex surface film.

Recovery of Fission Product Palladium from Acidic High Level Waste Solutions

Abstract The recovery of palladium from a synthetic pressurized heavy water reactor high level waste (PHWR-HLW) solution has been carried out, and the best reagents to use for the actual HLW solutions are discussed. The extraction of palladium from nitric acid solutions has been carried out using Cyanex-471X (triisobutylphosphine sulfide, TIPS) as the extractant. The metal ion could be quantitatively extracted from solutions with nitric acid concentrations between 2.0 and 6.0 M. The species extracted into the organic phase was found to be Pd(NO3)2 TIPS. Nitric acid in the range of 2. 0 to 5. 0 M had no effect on TIPS for at least 71 hours. A systematic study of gamma irradiation on loading and stripping of palladium from loaded organic phases using several potential extractants, TIPS, alpha benzoin oxime, dioctylsulfide, and dioctylsulfoxide has been made. A flow sheet for the recovery of palladium from actual HLW solutions using TIPS is proposed.

Differential pulse voltammetric determination of lead(II) with benzoin oxime‐modified carbon paste electrodes

AbstractA new chemically modified electrode (CME) for determining lead(II) with high sensitivity and selectivity is reported. The electrode is constructed by adding benzoin oxime into a carbon paste mixture. The lead(II) is accumulated on the electrode surface by the formation of the complex in an open circuit, and then the resulting surface is characterized by medium exchange, potential reduction, and differential pulse anodic stripping voltammetry. In 10 deposition/measurement/regeneration cycles with a single surface, the response could be reproduced with 5.7% relative standard deviation. Quantitation of lead(II) from the peak current of the anodic wave for a 10 minute deposition time gives a detection limit of 8 × 10−9 M (1.6 ppb). Linear calibration plots are obtained for lead(II) concentrations ranging from 10−7 to 10−8 M. The modified electrode preferentially accumulates lead from the solution, while most of the metal ions do not interfere with the determination. The mechanism of the accumulation of lead on the benzoin oxime‐modified electrode has been explored. Application to the determination of lead in wastewater is illustrated.

Adsorptive voltammetric determination of copper with a benzoin oxime graphite paste electrode

A method for the determination of trace amounts of copper with a chemically modified carbon press-formed electrode is described. Copper could be accumulated at the electrode by complexing with benzoin oxime in ammonia buffer, then reduced at a constant potential of −0.4 V ( vs. SCE) in nitric acid solution. Finally, a well-defined stripping peak could be obtained by scanning the potential in a positive direction. The response depends on the concentration of copper and accumulation time. For an accumulation time of 5 min the detection limit is about 1 ng/ml and the linear range is from 2 ng/ml to 4000 ng/ml, with a relative standard deviation of 5%. Many common metal ions have little or no effect on the determination of copper. The recommended procedure was applied to the determination of trace amounts of copper in natural water, and the results are in agreement with those of atomic-absorption spectrometry.

ChemInform Abstract: STEREOSELECTIVE CATALYTIC HYDROGENATION OF α‐HYDROXY KETOXIMES

AbstractDas ausgehend von dem optisch aktiven Aminalkohol (Ia) erhaltene Oxim (Va) wird stereoselektiv katalytisch zu den Aminoalkoholen (I) hydriert (Überschuß des erythro‐ Isomeren); analog reagiert auch das isomere Z‐Racemat (Vb) zu den entsprechenden racemischen Aminoalkoholen (68‐7l% Ausbeute; erythro :threo ‐ 89 : ll).

Stereoselective Catalytic Hydrogenation of α-Hydroxy Ketoximes

Abstract Two isomers(E and Z) of benzoin oxime and 2-hydroxy-1-phenyl-1-propanone oxime were catalytically hydrogenated by using palladium on charcoal and erythro amino alcohols were obtained in about 80% diastereomeric excess. The syn-anti isomerization of these oximes in the presence of palladium on charcoal was also studied in connection with the stereoselectivity of the catalytic hydrogenation of the oximes.

ChemInform Abstract: OPTICAL RESOLUTION OF 2‐AMINO‐1,2‐DIPHENYLETHANOL BY PREFERENTIAL CRYSTALLIZATION AND ITS UTILIZATION IN FRACTIONAL CRYSTALLIZATION AND ENANTIOSELECTIVE REDUCTION OF PROCHIRAL KETONES

AbstractDie Titelverbindung (I), durch katalytische Reduktion von Benzoinoxim zugänglich, läßt sich durch das Verfahren der bevorzugten Kristallisation in die optisch aktiven Formen trennen.

Optical Resolution of 2-Amino-1,2-diphenylethanol by Preferential Crystallization and Its Utilization in Fractional Crystallization and Enantioselective Reduction of Prochiral Ketones

Abstract (±)-erythro-2-Amino-1,2-diphenylethanol prepared from benzoin oxime by catalytic reduction was successfully resolved into a pair of optically active forms by preferential crystallization. The optically active amino alcohol was found to be useful as a basic resolving agent for the optical resolution of tartaric acid, trans-2,3-oxiranedicarboxylic acid, 2-hydroxy-2-phenylpropionic acid, and 3-endo-benzamido-5-norbornene-2-endo-carboxylic acid. Chiral hydrides prepared from lithium aluminium hydride and optically active threo- or erythro-2-amino-1,2-diphenylethanol derivatives were applied to the enantioface differentiating reduction of prochiral ketones to give the corresponding optically active alcohols in 26–72% optical purities.

Spectrophotometric determination of palladium(II) and platinum(IV) in presence of each other by ?-benzoin oxime

Spectrophotometric determination of palladium(II) and platinum(IV) in presence of each other by ?-benzoin oxime

Photoinduced Reactions. LXXIII. Solvent Dependence in the Photochemical Reaction of α-Nitroepoxides

Abstract The photochemical reaction of α-nitroepoxides showed marked solvent dependence. The photolysis of (1,2-epoxy-2-nitropropyl)benzene (I) in 2-propanol led to the formation of three products 1-phenyl-1-isopropoxy-2-propanone (IIb), 1-phenyl-1,2-propanedione oxime (III) and 1-hydroxy-1-phenyl-2-propanone oxime (IV), whereas on irradiation in ether I gave exclusively IV. However, in t-butyl alcohol, benzene, acetone, acetonitrile or n-hexane, I was not susceptible to photolysis. The photolysis of α,α′-epoxy-α-nitrobibenzyl (V) in ether gave benzoin oxime (VII) in addition to benzaldehyde and benzoic acid, whereas in methanol it gave benzoin methyl ether (VI) in the dark. These reactions are interpreted in terms of effects of the acidity and hydrogen-donating property of solvents on the excited α-nitroepoxides. The pyrolysis of I and V were also examined.

INFLUENCE OF ACTIVE IMMUNIZATION ON MELANIZATION OF THE BLOOD OF WAX MOTH LARVAE

Larval blood of the wax moth, Galleria mellonella (L.), immunized against Pseudomonas aeruginosa does not melanize on exposure to air as does normal blood. Larval blood samples taken 20 to 24 hours after vaccination against either of the pathogens P. aeruginosa or Proteus mirabilis did not melanize; blood of insects vaccinated against the nonpathogenic Shigella dysenteriae strain K 629 or a nonpathogenic strain of Pseudomonas did melanize. Injection of nonspecific agents, such as sodium chloride or egg albumen, did not inhibit melanization. The oxidation–reduction potential of immune blood was markedly lower than that of normal blood. Enzymes from both normal and immune blood were precipitated with cold acetone. The enzyme preparations were nontoxic to normal larvae. Both normal and immune blood enzyme preparations produced melanin from tyrosine, though the immune blood enzyme acted more slowly. Sodium thioglycollate, ascorbic acid, benzoin oxime, and phenylthiourea each inhibited the melanization of normal blood in vitro but did not confer bactericidal activity. These inhibitors did not produce any change in the rate of melanization, bactericidal activity, or immune properties of the blood when injected into larvae.

A proposed structure for the copper(ii) salts of α-acyloin oximes

The behavior of the copper (II) salts of the a-isomers of some acyloin oximes towards a series of selected amines was examined in order to study the unusual solubility relationships which these copper salts exhibit towards ammonium hydroxide. The insolubility in ammonium hydroxide of these copper salts of acyloin oximes has been attributed to their being inner complex salts. Evidence is presented which is contra y to this view. Based on the solubilities of the copper (II) salts investigated, a polymeric structure for copper (II) acyloin oximes is proposed. The study included the following α-isomers of acyloin oximes: benzoin oxime, 2,2'-furoin oxime, phenylbenzoin oxime, methylbenzoin oxime, 2,2'thenoin oxime, a-hydroxyisobutyrophenone oxime, and α-hydroxyacetophenone oxime. The last four compounds had not been examined previously as to their ability to form copper (II) salts.

ROT RESISTANCE OF COTTON DUCK TREATED WITH CHELATE COPPER COMPOUNDS

Thirteen organic compounds capable of forming chelate complexes were used to fix copper in cotton duck. Their rotproofing effectiveness was then determined by the loss in tensile strength during soil burial. The compounds tested were, in order of decreasing effectiveness, cupferron, 8-hydroxyquinoline, 1-nitroso-2-naphthol, dimethylglyoxime, salicylaldoxime, glucose oxime, diphenyl-thiocarbazone, rhodanine, benzoin oxime, s-diphenylcarbazide, acetoin oxime, and fructose oxime. Copper complexes formed with cupferron and 8-hydroxyquinoline possessed rot resistant properties far superior to those of copper naphthenate or any of the other compounds tested.