Tautomerism of 1-methyl-5-amino-2,3-dihydro-1,2,4-triazolium-1-alkylidene(or arylidene)-2-methylaminoguanidinium iodide

¹H and ¹³C NMR spectroscopy has been used to examine the structures of the products of the condensation of aldehydes and ketones with 1-methyl-1-aminoguanidinium iodide, which in some instances in solution are involved in a ring-chain tautomeric equilibrium between 1-methyl-5-amino-2,3-dihydro-1,2,4-triazolium iodide and 1-alkylidene(or arylidene)-2-methylaminoguanidinium iodide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1071–1074, August, 1987.     

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.     

The synthesis,structure and reactions of the novel cationic bisbut-2-yne complex [W(CO)(NCMe)(S2CNC4H8)(η2-MeC2Me)2][BPh4]

The complex [WI(CO)(S₂CNC₄H₈)(η²-MeC₂Me)₂] reacts with an equimolar amount of Na[BPh₄] in acetonitrile at room temperature to give the cationic bisbut-2-yne complex [W(CO)(NCMe)(S₂CNC₄H₈)(η²-MeC₂Me)₂][BPh₄] (1) by replacement of an iodide ligand by acetonitrile. The crystal structure of 1 has been determined and reveals a pseudo-octahedral geometry with the mid points of the two cis-but-2-yne ligands approximately coplanar with the sulphur atoms of the dithiocarbamate ligand. Carbon monoxide and acetonitrile occupy the axial sites. ¹³C NMR spectroscopy shows the two but-2-yne ligands in 1 donate a total of 6 electrons to the tungsten. Preliminary studies of the chemistry of 1 are also described.     

Complexation of Ba2+, Pb2+, Cd2+, and UO22+ Ions with 18-Crown-6 and Dicyclohexyl-18-Crown-6 in Nitromethane and Acetonitrile Solutions by a Competitive NMR Technique Using the 7Li Nucleus as a Probe

[⁷Li] NMR measurements were used to determine the stoichiometry and stability of Li⁺ complexes with 18-crown-6 and dicyclohexyl-18-crown-6 in nitromethane and acetonitrile solutions. A competitive [⁷Li] NMR technique was also employed to probe the complexation of Ba²⁺, Pb²⁺, Cd²⁺, and UO₂²⁺ ions with the same crown ethers–solvent systems. All the resulting 1 : 1 complexes were more stable in nitromethane than acetonitrile solution. In all cases, the stability of both crown complexes in nitromethane and acetonitrile varied in the order Pb²⁺ > Ba²⁺ > Li⁺ > Cd²⁺ > UO₂²⁺.     

Synthesis of New Metal‐Free 1,4,8,11‐Tetraaza[14]annulene Derivatives Using 2‐Heteroaryl‐substituted Trimethinium Salts

The reaction of 2‐heteroaryl‐substituted trimethinium salts (A, B, and C) with aromatic 1,2‐diamines ( a , b , c , d , and e ) in acetonitrile/acetic acid leads to 6,13‐disubstituted 1,4,8,11‐tetraaza[14]annulene derivatives ( 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ). The UV–vis spectral behavior of these compounds was examined in acetonitrile. Elemental analysis, IR, ¹H‐NMR, ¹³C‐NMR, and mass spectra confirm the molecular structure of the newly synthesized compounds.     

Synthesis,characterization, and organocatalytic application of chiral ionic liquids derived from (S,R)-noscapine

(S,R)-Noscapine, a phthalideisoquinoline alkaloid has been used as precursor for the synthesis of chiral ionic liquids (CILs). Noscapine based CILs have been synthesized from reaction between (S,R)-noscapine and methyl iodide in acetonitrile at room temperature. The synthesized CILs have been characterized by ¹H NMR, ¹³C NMR, EI-MS, and polarimetry techniques. These CILs have been used as organocatalysts in the enantioselective reduction of prochiral ketones to produce optically active secondary alcohols. The optically active secondary alcohols have been obtained with excellent yields and low to moderate enantiomeric excess (ee); also the complete enantiomeric excess (100% ee) has been achieved in some cases.     

2-羟基-1-萘甲醛缩-2-萘甲酰腙对Zn2+的选择性识别

设计合成了识别Zn²⁺的荧光传感分子--2-羟基-1-萘甲醛缩-2-萘甲酰腙(3)。 通过红外光谱、核磁共振谱和质谱测试技术表征了其结构。 利用其光谱性质研究了该物质对几种过渡金属离子的识别性质,初步探讨了其结合模式。 结果表明,在乙腈介质中,受体分子3表现出对Zn²⁺良好的选择性,Zn²⁺的加入导致受体分子3的吸收光谱在435 nm处出现1新峰,其吸光度逐渐增强,同时于239、302、330、342和387 nm处观察到5个清晰的等吸收点;在516 nm处荧光增强101倍,而其它过渡金属只引起受体分子]3的荧光略微增强。 Job法实验揭示受体分子3与Zn²⁺的结合比为1∶1。     

1-Methyl-2(3,4)-(1-vinylpyrrol-2-yl)pyridinium iodides: some structural features revealed by 1H and 13C NMR spectroscopy

The reactions of 2-, 3-, and 4-(1-vinylpyrrol-2-yl)pyridines with methyl iodide afford the corresponding quaternary salts. Analysis of their ¹H and ¹³C NMR spectra showed that the quaternization of the nitrogen atom considerably enhances the -acceptor effect of the pyridine ring on the pyrrole ring and on the vinyl group. 1-Methyl-2-(1-vinylpyrrol-2-yl)pyridinium iodide contains no weak intramolecular C--H...N hydrogen bond present in the starting compound.     

Competitive 7Li NMR Study on the Mn2+, Zn2+ and Cd2+ Complexes of Two New Branched Hexadentate (N6) Amines Containing the Pyridine Moiety in Nitromethane and Acetonitrile Solutions

Lithium-7 NMR spectroscopy was used to investigate the stoichiometry and stability of a Li⁺ complex with two new branched amines, 4,7-bis(2-pyridylmethyl)-4,7-diazadecane-1,10-diamine (L¹) and 4,8-bis(2-pyridylmethyl)-4,8-diazaundecane-1,11-diamine (L²), in acetonitrile and nitromethane. A competitive ⁷Li NMR method was also employed to probe the complexation of Mn²⁺, Zn²⁺ and Cd²⁺ ions with L¹ and L² in the same solvent systems. The formation constants of the resulting complexes were evaluated from computer fitting of the mole ratio data with an equation that relates the observed chemical shifts to the formation constant. In both solvents, the stability of the resulting 1:1 complexes was found to vary in the order Cd²⁺ > Zn²⁺ > Mn²⁺ > Li⁺.     

Copper-sulfur interactions: synthesis and structure of a trigonal planar copper(I) complex with bis(diphenylthiophosphinyl)methane, [CuI(dppmS2)]·MeCN

Reaction of copper(I) iodide with 1,1-bis(diphenylthiophosphinyl)methane (dppmS₂) in a 1:1?mol ratio in acetonitrile yielded a complex of stoichiometry [CuI(dppmS₂)]·CH₃CN (1) whose X-ray structure determination has shown that the geometry around the copper center is nearly trigonal planar. Acetonitrile is nonbonded. Copper–sulfur bond distances are 2.2470(7) and 2.2591(7)?Å, while the copper–iodide bond distance is 2.4937(5)?Å. IR and NMR spectroscopic data also show the formation of copper–sulfur bonds. Lack of bridging by iodide led to the formation of a three-coordinate copper complex, as against the expected iodo-bridged dimeric complex with chelating dppmS₂.     

Synthesis of 3-(3-Methyl-1-aryl-1H-pyrazol-5-yl)-2H-2-chromen-2-one Derivatives via a One-Pot,Three-Component Reaction

An efficient synthesis of 3-(3-methyl-1-aryl-1H-pyrazol-5-yl)-2H-2-chromen-2-one derivatives by the reaction of salicylaldehydes, 4-hydroxy-6-methyl-2H-pyran-2-one, and arylhydrazine in acetonitrile under reflux condition and in the presence of piperidine is reported. This three-component reaction has some advantages such as ease of handling, good yields, and easy purification. All structures were confirmed by infrared, mass, ¹H NMR, and ¹³C NMR spectroscopy.     

Solid state and solution NMR studies of some new complexes of mercury selenocyanate with imidazolidine-2-thione and its derivatives

Reactions of imidazolidine-2-thione (Imt), 1,3-diazinane-2-thione (Diaz) and 1,3-diazipane-2-thione (Diap) with mercury(II) selenocyanate in acetonitrile resulted in formation of 2?:?1 complexes. Both solid state and solution NMR, confirm the exocyclic sulfur atom to be the donor in all cases. ¹⁹⁹Hg shielding tensors and anisotropies were calculated from the solid-state NMR spectra. Based on the solid NMR data a distorted tetrahedral disposition of ligands around mercury is proposed.     

Kinetics and mechanism of 5-vinyltetrazole alkylation

Alkylation of NH-unsubstituted 5-vinyltetrazole with methyl iodide in the presence of triethylamine in acetonitrile solution led to the formation of isomeric 1- and 2-methyl-5-vinyltetrazoles in 1:1 ratio. The reaction rate constants were measured at 25–55°C. According to the thermodynamic parameters of the reaction [ΔH ^≠ 66 kJ mol^?1, ΔS^≠-74 (mol K)^?1, 298 K] the limiting stage of the reaction consists in the electrophilic attack of methyl iodide on an H-complex of the heterocycle with triethylamine.     

Linearly and circularly polarized raman spectra of the iron (II) bis[1-(2'-pyridylmethyleneamino)-2-aminoethane] ion evidence for asymmetric raman tensor

Raman spectra of solutions of iron(II)bis[1-(2'-pyridylmethyleneamino)-2-aminoethane] iodide in acetonitrile were recorded using both linearly and circularly polarized light for excitation. The tensor invariants 45$\text{}\text{?}$ga², 7γ_s² and 5γ_as² were determined for three prominent lines with 488.0, 514.5 and 528.7 nm excitation. With two of the lines, significant anti-symmetric anisotropies are found.     

Preparation,properties and x-ray crystal structure of a complex of bis(triphenylphosphoranylidene)ammonium iodide with 7,7,8,8-tetracyano-P-quinodimethane: (PPN)2(TCNQ)3(CH3CN)2

Bis(triphenylphosphoranylidene)ammonium iodide (PPN⁺I^?) forms a 2:3 complex with TCNQ [(PPN)₂(TCNQ)₃(CH₃CN)₂] that provides an example of a TCNQ complex containing acetonitrile in the crystal lattice; the material is a semi-conductor with trimerised TCNQ stacks.     

Methanol and acetonitrile associates in aqueous and chloroform solutions according to 1H NMR spectroscopic data

Association of methanol and acetonitrile in a nonpolar (CDCl₃) and polar (H₂O and D₂O) solvents was studied by ¹H NMR spectroscopy and quantum chemistry. The results were compared with the data obtained by decomposition of the spectral curves in the range 800–1100 nm by the independent component analysis (ICA) technique. The content of homoassociates consisting of four and two or three molecules in the case of methanol and acetonitrile, respectively, gradually increased with the amount of the organic solvent in solution. The aqueous solutions under study consisted of few associates of compositions 1: 1, 1: 2, and 1: 4.5 for acetonitrile and 1: 1 and 1: 3 for methanol (water: organic solvent). The quantum-chemical calculation of the NMR spectra of the particles existing in solution confirmed our conclusions about the structure of the solutions.     

Sonocatalyzed facile synthesis of 2-aryl benzoxazoles using MnO2 nanoparticles as oxidant agent under mild conditions

Nano MnO₂ was found to be an efficient oxidant agent for the synthesis of 2-substituted benzoxazoles through one-pot reaction of o-aminophenol and different aromatic aldehydes in acetonitrile under ultrasonic irradiation. This method was performed under mild conditions with high yields, inexpensive and readily available oxidant agent, facile and easy experimental procedure, simple purification of final products, and short reaction times. The prepared nano MnO₂ has been characterized by FTIR, XRD, and SEM techniques. The pure products were identified and characterized by physical and spectroscopic data such as; melting point, IR, ¹H NMR, and ¹³C NMR.     

Synthesis,Crystal Structure and Characterization of Hexakis[2‐methoxy‐4‐formylphenoxy]cyclotriphosphazene

The new cyclotriphosphazene derivative N₃P₃(OC₆H₃OCH₃COH)₆ ( 1 ) was synthesized from hexachlorocyclotriphosphazene, N₃P₃Cl₆, and 4‐hydroxy‐3‐methoxybenzaldehyde in acetonitrile in the presence of K₂CO₃. The structure of 1 was verified by means of elemental analysis, IR, ¹H NMR, ¹³C NMR, ³¹P NMR spectra, thermal analysis and X‐ray diffraction.     

二维多孔铜-间苯二腈配位聚合物用于阴离子交换及客体分子可逆吸附性的研究

The 2D porous copper（Ⅰ） complex with 1,3-dicyanobenzene （DCB）, [Cu（DCB）2]（PF6）（Me2CO） 1, exhibits channels along axis c, in which one molecule acetone and one anion PF6 per formula unit are included respectively. The reversible incorporation of guest acetone and acetonitrile, as well as the anion exchange from PF6^- to BF4^- or CF3SO3^-, was investigated by thermogravimetric （TG） analysis, ^1H NMR spectra and/or infrared absorption spectroscopy. Additionally, the incorporation of benzene and toluene into complex 1 was also discussed. Complex 1 exhibited size selectivity for guest inclusion or anion exchange.     

One‐step synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate and its characterization with 1D and 2D NMR techniques

A one‐step method was reported for the synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate by treating 7‐acetamido‐4‐hydroxy‐2‐naphthalenesulfonyl chloride with equal moles of N, N‐dimethylethylenediamine in acetonitrile in the presence of K₂CO₃. The chemical structure of the obtained compounds was characterized by MS, FTIR, ¹H NMR, ¹³C NMR, gCOSY, TOCSY, gHSQC, and gHMBC. The chemical shift differences of ¹H and ¹³C being δ 0.04 and 0.2, respectively, were unambiguously differentiated. Copyright © 2013 John Wiley & Sons, Ltd.