Synthesis,spectral characterization,thermal study and antimicrobial activity of (E)-4-(substituted 1-Benzo[d]imidazole-2-yl)-N'-(substituted Benzylidene)benzohydrazide schiff bases

Antimicrobial properties casing wide applicability in water detoxification, pharmaceutics and in industries. Present work focus on the synthesis of a new series of Schiff Bases (E)-4-(1 substituted-1H Benzo[d]imidazole-2-yl)-N'-(substituted Benzylidene)benzohydrazide (5a-5l) were synthesized. The convenient route for the synthesis of new analogues by the condensation of 4-(substituted -1H-Benzo[d]imidazole-2-yl)-N'- Hydrazine with different derivatives of aromatic aldehydes were described using different solvents and catalysts. The structures of the synthesized compounds were ascertain by spectral techniques viz. IR, ¹H NMR, MS and Physical Elemental data. Compounds were also subjected to thermal analysis to study their physical and chemical properties. The title compounds were also screened for their antimicrobial activity against various bacterial & Fungal strains. Results of bioassay vary with diverse group attached to Benzimdazole motif and could be helpful for the development of other bioactive molecules.     

A Facile and Efficient Synthesis of Arylsulfonamido‐Substituted 1,5‐Benzodiazepines and N‐[2‐(3‐Benzoylthioureido)aryl]‐3‐oxobutanamide Derivatives

A facile and efficient synthesis of 1,5‐benzodiazepines with an arylsulfonamido substituent at C(3) is described. 1,5‐Benzodiazepine, derived from the condensation of benzene‐1,2‐diamine and diketene, reacts with an arylsulfonyl isocyanate via an enamine intermediate to produce the title compounds of potential synthetic and pharmacological interest in good yields (Scheme 1). In addition, reaction of benzene‐1,2‐diamine and diketene in the presence of benzoyl isothiocyanate leads to N‐[2‐(3‐benzoylthioureido)aryl]‐3‐oxobutanamide derivatives (Scheme 2). This reaction proceeds via an imine intermediate and ring opening of diazepine. The structures were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 3).     

Multivariate approach for the enantioselective analysis in MEKC‐MS: II. Optimization of 1,1′‐binaphthyl‐2,2′‐diamine in positive ion mode

Enantiomeric separation and detection of 1,1′‐binaphthyl‐2,2′‐diamine (BNA) has been successfully optimized by MEKC‐ESI‐MS using a polymeric surfactant polysodium N‐undecenoxycarbonyl‐L‐leucinate (poly‐L‐SUCL) as a pseudostationary phase. In the first step, MEKC conditions were optimized by a five‐factor three‐level central composite design (CCD) of experiment. All five MEKC factors (buffer pH, percentage of ACN in the running buffer, concentration of surfactant, concentration of ammonium acetate (NH₄OAc), and voltage) were found significant to the responses (measured as the chiral resolution and analysis time). The interactions between MEKC factors were further evaluated using a quadratic model equation which allowed the generation of 3‐D response surface image to reach the optimum conditions. To obtain the best S/N, sheath liquid composition and spray chamber parameters were successfully optimized using the same strategy. Baseline enantiomeric resolution in less than 20 min and optimum MS signal of BNA enantiomers (S/N = 45 at 0.4 mg/mL) were ultimately achieved at the optimized conditions. The adequacy of the model was validated by experimental runs at the optimal predicted conditions. The predicted results were found to be in good agreement with the experimental data.     

Current trends in the detection of peroxide-based explosives

The increased use of peroxide-based explosives (PBEs) in criminal and terrorist activity has created a demand for continued innovation in the detection of these agents. This review provides an update to a previous 2006 review on the detection of PBEs, with a focus in this report on luminescence and fluorescence methods, infrared and Raman spectroscopy, mass spectrometry, and electrochemical techniques. Newer developments in gas chromatography and high performance liquid chromatography methods are also discussed. One recent trend that is discussed is an emphasis on field measurements through the use of portable instruments or portable assay formats. An increase in the use of infrared spectroscopy and mass spectrometry for PBE analysis is also noted. The analysis of triacetone triperoxide has been the focus in the development of many of these methods, although hexamethylene triperoxide diamine has received increased attention in PBE detection during the last few years.     

Preparation and Characterization of Novel Polyimides with Hydroxyl Groups

3,3′-diamino-4,4′-dihydroxybiphenyl (DADHBP) was synthesized and its chemical structure was confirmed by Fourier transform infrared (FT-IR) spectroscopy, ¹H-nuclear magnetic resonance (¹H-NMR), and differential scanning calorimetry (DSC). Then six poly(amic acid) (PAA) solutions were prepared by copolymerization of DADHBP, oxydiphthalicanhydride (ODPA), and 2,2-bis [4-(4-aminophenoxy)phenyl] propane (BAPOPP) in N,N-dimethylacetamide (DMAC) in different mole ratios. The polyimide (PI) films were obtained through thermal imidazation reactions of the thin layers of the above-mentioned precursor solutions. Chemical structures of all PI films were demonstrated by FT-IR. Thermal stabilities and decomposition behaviors of the PI films were tested by DSC and thermogravimetric analysis (TGA). Thermal measurements indicate that the polymers have high thermal stability and produce high char yields. The properties of the PI films were further studied by ultraviolet–visible spectroscopy, water absorption, surface energy, and mechanical measurements. Thermal analysis showed glass transition temperatures between 205.9°C and 276.7°C. Decomposition temperatures were higher than 360.2°C, with 10% weight losses in the range of 448.6°C～517.8°C. The prepared PI films also exhibited good UV absorption, low water absorption (<2%), low surface energy (<44.28 mJ/m²), and good mechanical properties.     

Quinone-amine polymers. XII. Synthesis and characterization of novel polymers from 2-phenylbenzoquinone and aliphatic diamines

In order to study the effect of the presence of phenyl groups in poly (amino-quinone) (PAQ) polymers, several novel poly(amino-2-phenylbenzoquinone) (PhPAQ) polymers have been prepared from 2-phenylbenzoquinone and aliphatic diamines, such as 1,6-diaminohexane, 1,8-diaminooctane, 1,12-diaminodod+++++, and 1,4-diaminocyclohexane. Prior to the polymerization, 2-phenylbenzoquinone was generated in situ from 2-phenylhydroquinone in the presence of calcium hypochlorite as the oxidizing agent in dichloromethane. All of the polymers synthesized have been characterized with respect to their corresponding model compounds. It was also found that unlike their analogous PAQ polymers, PhPAQ polymers were highly soluble in many common organic solvents because of the presence of phenyl groups in their polymer backbone. © 1994 John Wiley & Sons, Inc.     

Dissolution of cellulose in ethylene diamine/salt solvent systems

Investigation of the dissolution of cellulose in Ethylene Diamine (EDA)/Potassium thiocyanate (KSCN) solutions by infrared spectroscopy (FTIR) and thermal analysis (DSC) indicated that changes to the solvent during freeze thaw cycling of mixtures was consistent with increased interaction between cellulose and solvent. Thermal transitions in the system, however, occurred at temperatures outside the range used in thermal cycling to promote dissolution. Further exploration of the dissolution and mixing process indicated that mixing was the limiting step in solution formation. The dissolution of two types of cellulose with different molecular weights (Degree of Polymerization (DP)=210 and >1000) was studied using EDA/KSCN solution as the solvent. The solubility and the dissolution rate of cellulose depended on both the solvent composition and cellulose molecular weight. Cellulose could dissolve faster in the solvent with lower salt concentration but the highest cellulose concentration was obtained in the solvent with 30~35% KSCN. Rheological measurements showed that cellulose solutions exhibited viscous solution behavior at low KSCN concentration but primarily elastic behavior at high salt concentration.     

Synthesis and Characterization of New Macrocyclic Cu（Ⅱ） Complexes from Various Diamines, Copper（Ⅱ） Nitrate and 1,4-Bis（2-formylphenoxy）butane

Six new macrocyclic complexes were synthesized by a template reaction of 1,4-bis（2-formylphenoxy）butane with diamines and Cu（NO3）2·3H2O and their structures were proposed on the basis of elemental analysis, FT-IR, UV-Vis, magnetic susceptibility measurements, molar conductivity measurements and mass spectra. The metal to ligand molar ratios of the Cu（Ⅱ） complexes were found to be 1 ： 1. The Cu（Ⅱ） complexes are 1 ： 2 electrolytes as shown by their molar conductivities （∧m） in DMF at 10^-3 mol·L^-1. Due to the existence of free ions the Cu（Ⅱ） complexes are electrically conductive. Their configurations were proposed to be probably distorted octahedral.     

Zur Reaktion der Alkin-Kupfer(I)-Komplexe [CuX(S-Alkin)] (X = Cl,Br, I; S-Alkin = 3,3,6,6-Tetramethyl-1-thia-4-cycloheptin) mit dem Chelat-Liganden N,N,N′,N′-Tetramethylethylendiamin (tmeda)

Organometallic Compounds of Copper. XVII. On the Reaction of the Alkyne-Copper(I) Complexes [CuX(S-Alkyne)] (X = Cl, Br, I; S-Alkyne = 3,3,6,6-Tetramethyl-1-thiacyclohept-4-yne) with the Chelate Ligand N,N,N′,N′-Tetramethylethylendiamine (tmeda) The alkyne copper(I) chloride complex [CuCl(S-Alkyne)]_n ( 2 a ) (S-Alkyne = 3,3,6,6–tetramethyl-1-thiacyclohept-4-yne) adds tetramethylethylene diamine (tmeda) to form the mononuclear compound [CuCl(S-Alkyne)(tmeda)] ( 4 ). The alkyne copper halide complexes [CuBr(S-Alkyne)]_n ( 2 b ) and [CuI(S-Alkyne)]_n ( 2 c ) react with tmeda to yield the complex salts [Cu(S-Alkyne)(tmeda)]⁺ [CuX₂(S-Alkyne)]^– (X = Br ( 5 a ), X = I ( 5 b )). X-ray diffraction studies on all new compounds 4 and 5 reveal distorted tetrahedral coordination of the copper atom in complex 4 and trigonal-planar coordinated copper atoms in the cations and anions of the ionic compounds 5 .     

一些中环二胺氢溴酸盐的合成

以1,3－二氯－2－丙醇及N,N′－二对甲苯磺酰胺（2a,2b)为起始原料,通过关环反应合成新化合物（3a,3b),然后脱去3a,3b的对甲苯磺酰胺,得到标题化合物（4a,4b）。本文从分子内与分子间反应的竞争及反应物2a,2b的分子结构两方面讨论了对关环反应产率的影响。