Synthesis,antimicrobial and cytotoxic activity of novel azetidine-2-one derivatives of 1H-benzimidazole

A series of 1-methyl-N-[(substituted-phenylmethylidene)-1H-benzimidazol-2-amines (4a–4g) were prepared via the formation of 1-methyl-1H-benzimidazol-2-amine (3), which was prepared by the cycloaddition of o-phenylenediamine (1) with cyanogen bromide in the presence of aqueous base followed by N-methylation with methyl iodide in the presence of anhydrous potassium carbonate in dry acetonitrile. Moreover, the four-membered β-lactam ring was introduced by the cycloaddition of 4a–4g and chloroacetyl chloride in the presence of triethylamine catalyst to give 3-chloro-1-(1-methyl-1H-benzimidazol-2-yl)-(4′-substituted)-phenylazetidin-2-one 5a–5g. A total of 14 compounds were synthesized and characterized by IR, ¹H NMR, ¹³C NMR and Mass spectral technique, in addition they were evaluated for anti-bacterial and cytotoxic properties. Among the chemicals tested 4a, 4b, 5a, 5b, 5g exhibited good antibacterial activity and 5f, 5g shown good cytotoxic activity in vitro.     

Non‐self‐adjoint Bessel and Sturm–Liouville boundary value problems in limit‐circle case

It is shown in the limit‐circle case that system of root functions of the non‐self‐adjoint maximal dissipative (accumulative) Bessel operator and its perturbation Sturm–Liouville operator form a complete system in the Hilbert space. Furthermore, asymptotic behavior of the eigenvalues of the maximal dissipative (accumulative) Bessel operators is investigated, and it is proved that system of root functions form a basis (Riesz and Bari bases) in the same Hilbert space. Copyright © 2014 John Wiley & Sons, Ltd.     

不对称双席夫碱过渡金属配合物的电子光谱和非线性光学性质的理论研究

本文采用密度泛函理论中的M05方法对比研究了一类双席夫碱及其衍生物与金属Co、Ni和Cu配位后配合物的结构,非线性光学性质以及激发态性质.结果表明,Co配合物的三重态,Ni配合物的二重态以及Cu配合物的单重态为最佳稳定结构.通过最佳稳定结构计算得到的配合物非线性光学性质表明,三种金属配合物中Cu配合物表现出较高的一阶和二阶超极化率.通过对其激发态性质分析表明在配体苯环上引入甲氧基使电子跃迁种类减少,导致超极化率下降,非线性光学性质减弱.     

Catalytic Transfer Hydrogenation of Aromatic Nitro Compounds by Employing Ammonium Formate and 5% Platinum on Carbon

Aromatic nitro compounds were reduced to respective amines in high yields by using 5% platinum on carbon with ammonium formate or formic acid as hydrogen donor. It was observed that the former was more efficient donor than the later. Further we have found that reduction of nitro groups occurs without hydrogenolysis of halogens and the reducible substituents which remains unchanged under the reaction conditions.     

Simple and Efficient Procedure for the Synthesis of Symmetrical Bis-Schiff Bases of 5,5′-Methylenebis(2-aminothiazole) Under Solvent-Free Conditions

A simple and efficient procedure for the synthesis of symmetrical bis-Schiff bases has been described that employs a condensation reaction of symmetrical primary bis-amine of 5,5′-methylenebis(2-aminothiazole) with a series of aromatic aldehyde derivatives under solvent-free conditions at elevated temperature. The advantages of these reactions are simplicity of the reaction procedure, short reaction times, simple workup, catalyst-free conditions, and pure products in good to excellent yields. Details of the reaction conditions are discussed.     

Exclusive 1,2-Reduction of Functionalised Conjugated Aldehydes with Sodium Triacetoxyborohydride

Functionalised α, β-unsaturated aldehydes were exclusively reduced to allylic alcohols with sodium-triacetoxyborohydride. Neither saturated alcohol nor saturated aldehydes are obtained. Conjugated ketones are not reduced.     

Synthesis and Characterization of S-Triazine Cored Tripodal Keto-oxime and Its Trinuclear Complexes

2,4,6-Tris(4-hydroxybenzimino)-1,3,5-triazine (II) has been synthesized by the reaction of 1 equiv. melamine (I) and 3 equiv. 4-hydroxybenzaldehyde and characterized by means of elemental analysis, ¹H NMR, Fourier transform–infrared spectroscopy, and liquid chromatography–mass spectrometry (LC-MS). 2,4,6-tris(4-(2-phenyl-2-keto-hydroxyiminoyloxy)benzimino)-1,3,5-triazine L (III) has been synthesized by the reaction of 1 equiv. II and 3 equiv. chloroisonitrozoacetophenone and characterized by means of the same methods. Four novel trinuclear Fe(III) and Cr(III) complexes involving tetradentate Schiff bases N,N′-bis(salicylidene)ethylenediamine-(salenH₂) or bis(salicylidene)-o-phenylenediamine-(salophen H₂) with L (III) have been synthesized and characterized by means of elemental analysis, Fourier transform–infrared spectroscopy, LC-MS (ESI⁺), and thermal analyses. The metal ratios of the prepared complexes have been determined using atomic absorption spectroscopy. The aim of the present study is to synthesize novel tridirectional-trinuclear systems and to present their effects on magnetic behavior of [salen or salophenFe(III)/Cr(III)] capped complexes. The complexes have also been characterized as low-spin distorted octahedral Fe(III) and as distorted octahedral Cr(III) bridged by keton-oxime group.     

SALT,SOLVENT AND SUBSTITUENT EFFECTS IN THE HYDROXIDE AND ALKOXIDE PROMOTED DECOMPOSITION OF PHOSPHONIUM COMPOUNDS

Abstract

The 1,2,3-trithiolan of endo-dicyclopentadiene, C₁₀H₁₂S₃ (1) can be polymerized to give low molecular weight polymers (C₁₀H₁₂S₃)_n, n = 3–6, by heating or by exposure to UV irradiation. The polymers differ according to the method of polymerization as revealed by their n.m.r. spectra. Depolymerization of both types of polymer can be achieved by heating with amines, and especially with R₃N. Desulphurization of (1) by Na₂SO₃ or triphenylphosphine produces a polymer of composition (C₁₀H₁₂S₂)_n, n= ca 18–19. The depolymerization of this material by Et₃N regenerated some (1).     

Synthesis,Spectroscopic Studies,and In Vitro Antifungal Activity of Organosilicon(IV) and Organotin(IV) Complexes of 4-Amino-5-mercapto-3-methyl-S-triazole Schiff Bases

The Schiff bases derived from condensation of s-triazole with heterocyclic aldehydes and their 1:1 and 1:2 complexes have been synthesized. These complexes have been characterized by elemental analyses, molar conductance and spectroscopic studies, including UV, IR, ¹H, ¹³C, ²⁹Si, and ¹¹⁹Sn NMR spectroscopy. On the basis of these studies, the resulting complexes have been proposed to have trigonal bipyramidal and octahedral geometries. The biological activity of these complexes against various fungi has been investigated.     

Thieno[2,3-c]pyridazine Derivatives: Synthesis and Antimicrobial Activity

Thieno[2,3-c]pyridazine 2 was selected as the starting material for the synthesis of some novel 5-arylidene amino and 5-thiazolidine derivatives. The structures of the synthesized compounds were elucidated by elemental analyses and spectral data. The antimicrobial and antifungal activities of the newly synthesized products were measured against some microorganisms.