Conformational Control of a Polyether-Linked Porphyrin Dimer Induced by Complexation with a Sodium Cation

Abstract

A porphyrin dimer with a polyether linkage was newly synthesized and its conformational change triggered by complexation with an sodium cation was examined. It was confirmed by ¹H NMR titration experiments that the dimer bearing a pentaoxyehtylene linkage (1b) was effectively formed a 1:1 complex with a sodium perchlorate. A detailed investigation of the CIS values for the protons confirmed that the complex of 1b?Na⁺ adopts a slipped face-to-face conformation.     

The Determination of Sodium in Alumina Using a Sodium Selective Ion Electrode

Abstract

A method has been developed for the determination of sodium in alumina using a selective ion electrode. The alumina sample is dissolved in ammonium hydrogen fluoride in platinum crucibles or sintered with boric acid using either platinum, nickel, or zirconium crucibles. Either dissolution technique completely extracts all available sodium. After dissolution, and in the presence of citrate to prevent aluminum hydroxide precipitation, the pH is adjusted to 8.7 with ammonium hydroxide, and the sodium concentration is determined by a sodium selective ion electrode.     

Facile Derivatizations of Heptamethine Cyanine Dyes

Treatment of dye 3 with sodium methoxide, morpholine, or diphenylphosphine gives the respective substituted derivatives 4, 5 and 6 in high yields. The reaction of 3 with sodium acetate followed by workup affords ketone 7 which is also obtained by demethylation of a methoxy derivative 4 under non-hydrolytic conditions.     

A Short,Affordable, One-Pot Synthesis of a Camphor-Derived Amino Alcohol

The commercially available α-ketoxime of camphorquinone (1) was reduced to the corresponding exo,exo-amino alcohol (2) in a two-step, one-pot procedure using sodium borohydride and nickel(II) chloride hexahydrate.     

The Allylic Rearrangement. V.1 Reaction of 4-Haloisophorone with Sodium Methoxide in Methanol

Treatment of 4-bromoisophorone with sodium methoxide gave 2-methoxyisophorone (4). Reaction of 4-chloroisophorone with sodium methoxide at 65–70° C afforded Favorskii-type rearangement product along with 4.     

Synthesis of sulfonamides promoted by alkyl iodide via a hypervalent iodine intermediate

Abstract

A new method for the preparation of sulfonamides from sodium sulfinates and amines is developed. A stoichiometric amount of m-chloroperbenzoic acid as oxidant and a catalytic amount of 1-iodopropane provides the corresponding sulfonamides in good yields under mild reaction conditions. In this protocol, 1-iodopropane is first oxidized by m-chloroperbenzoic acid into the corresponding hypervalent iodine intermediate iodosylpropane, which is highly unstable and decomposes at once to form hypoiodous acid. Then, the following reaction of the generated active hypoiodous acid with sodium sulfinates and amines results in the corresponding sulfonamides.     

Synthesis and Structures of 3,5-disubstituted 1,2,4-triazole Head Units and Incorporation of 3,5-dibenzoyl-1,2,4-triazolate into New [2 + 2] Schiff-Base Macrocyclic Complexes

The synthesis and characterization of sodium 3,5-diacetyl-1,2,4-triazolate (4 ^Me ) and sodium 3,5-dibenzoyl-1,2,4-triazolate (4 ^Ph ), both of which can be used as head unit building blocks in Schiff-base reactions, are reported. The crystal structures of sodium 3,5-diacetyl-1,2,4-triazolate, as [4 ^Me (H₂O)]_∞, and sodium 3,5-dibenzoyl-1,2,4-triazolate, as [4 ^Ph (CH₃OH)₂]₂, have been determined. The former is a helical polymer whilst the latter is a methanol-bridged dimer. The lead(II) templated cyclization reaction of sodium 3,5-dibenzoyl-1,2,4-triazolate (4 ^Ph ) with 1,3-diaminopropane or 1,4-diaminobutane, respectively, leads to the formation of two new [2 + 2] Schiff-base macrocycles as their lead(II) complexes, [Pb₂ L ^3Ph (μ-OH)]ClO₄ (5) and [Pb₂ L ^4Ph (μ-OH)]ClO₄ (6), respectively. Transmetallation of 5 with nickel(II) ions yields a novel, structurally characterized, dinickel(II) macrocyclic complex, [Ni₂ L ^3Ph (NCS)₂] (7), which features double triazolate bridging of the two five-coordinate nickel(II) ions.     

Reduction of 2-amino-1-(4-nitrophenyl)-1 H-pyrido[3,2-b]indole-3-carbonitrile by sodium borohydride and sodium cyanoborohydride

The reduction of pyridoindole derivative 1 by sodium borohydride in methanol gives 4,5-dihydropyridoindole 2. On treatment of 5H-pyrido[3,2-b]indolium chloride 3 with sodium cyanoborohydride in methanol in the presence of hydrogen chloride, reduction of the pyridine ring is accompanied by reduction of the CN group, resulting in the formation of tetrahydropyridoindole 4. Compound 4 reacts with DMF dimethyl acetal to yield amidine 6, and refluxing of 4 with acetic anhydride results in tetrahydropyridine ring cleavage yielding indolylacrylonitrile 9. The hydrochloride and chloride of compounds 4 and 6 were obtained     

Theoretical study of structure and properties of hexuronic acid and <Emphasis Type="SmallCaps">d</Emphasis>-glucosamine structural units of glycosaminoglycans

The Becke3LYP functional of DFT theory was used to investigate molecular structure and sodium affinity of the systems CH₃CO₂Na (1), CH₃–O–SO₃Na (2), CH₃–NH–SO₃Na (3), saccharide_1Na₂ (4), saccharide_2Na (5), saccharide_3Na₃ (6), saccharide_4Na₂ (7), and saccharide_5Na₂ (8), respectively, which are models of N- and O-sulfate glycosaminoglycans. Interaction enthalpies, entropies and Gibbs energies of the sodium-coordinated systems in the gas phase were determined with the B3LYP/6-311+G(d,p) and B3LYP/6-31+G(d) methods. The computed Gibbs energies, ΔG ^o , of model systems 1–3 are negative and span a rather broad energy interval (from −500 to −1,500 kJ mol⁻¹). Gibbs interaction energies for sodium acetate, sodium sulfate and sodium sulfamate functions of the five saccharides, systems 4–8 are always lower than those values found for the model compounds 1–3. The ionization of sodium salts of saccharides studied in gas phase is in most cases connected with considerable conformational rearrangement of the ionic species. This rearrangement causes an additional energetic stabilization of anionic species and is connected with the substantial release of entropy.     

Synthesis of Some 2-(3-Alkyl/aryl-5-trifluoromethylpyrazol-1-yl)-4-(coumarin-3-yl)thiazoles as Novel Antibacterial Agents

Abstract

Herein, we describe a one-pot synthesis of some novel 2-(3-alkyl/aryl-5-trifluoromethylpyrazol-1-yl)-4-(coumarin-3-yl)thiazoles (6) involving the reaction of 3-alkyl/aryl-5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazole-1-thiocarboxamides (3) with 3-bromoacetylcoumarins (5) in the presence of sodium carbonate in ethanol. Reaction of 3 with 5 in the absence of sodium carbonate, however, resulted in the formation of 2-(3-alkyl/aryl-5-hydroxy-5-trifluoromethyl-4,5-dihydropyrazol-1-yl)-4-(coumarin-3-yl)thiazoles, which were subsequently dehydrated to 6 by refluxing in ethanol in the presence of sodium carbonate. The structure of the synthesized compounds (6) was confirmed by infrared (IR), mass, ¹H NMR, and ¹³C NMR spectra and elemental analysis data. Newly synthesized compounds (6) showed moderate to good activity against Gram-positive bacteria.     

Sodium-mediated self-assembly of two nickel(II) Schiff base complexes: crystal structure and characterizations

Sodium-assisted self-assembly of two nickel(II) Schiff base complexes under similar reaction conditions yield hetero-metallic compounds [{Ni(salpn)}₂Na(ClO₄)] (1) and [{Ni(salpr)}₃Na][Ni(salpr)]₂ClO₄·2H₂O (2) (where salpn?=?N,N′-bis-(salicylidene)-1,3-diaminopropane and salpr?=?N,N′-bis-(salicylidene)-1,2-diaminopropane). Both have been characterized by physico-chemical techniques and single-crystal X-ray diffraction. Crystal structure reveals that in the tri-metallic system of 1 sodium is sandwiched between two [Ni(salpn)] units while the hexametallic system of 2 consists of tetrametallic cluster ion [{Ni(salpr)}₃Na]⁺ with encapsulated sodium by three [Ni(salpr)] units. In both complexes, sodium adopts distorted trigonal prismatic geometry leaving nickel(II) in a distorted square-planar environment. Structural characterization also reveals that 2?:?1 (for 1) and 3?:?1 (for 2) self-assemblies of metallo-ligand and sodium were achieved with slight variation in ligand backbone.     

Development and characterization of biodegradables packaging obtained from biopolymers mixture

The aim of this work is the development and the characterization of biodegradables films obtained from a mixture of soluble starch and sodium alginate. The influence of sodium alginate ratio on the behavior of these films is also studied in order to use them as new formulations to produce food packaging. The obtained films are generally homogeneous, thin, smooth and having a good coherence with no visual defects. The results of the FITR, SEM and XRD tests have shown the existence of a good compatibility, between alginate and starch due to both kind of strong interactions like hydrogen bonds and ionic interactions. Water sorption isotherm, water vapor permeability, and mechanical tests were strongly influenced by the addition of sodium alginate in the different formulations. This influence is caused by the plasticization effect of sodium alginate.     

Synthesis,characterization and antimicrobial study via new heterocyclic derivatives of trimethoprim

New compounds of trimethoprim heterocyclic derivatives were synthesized. These compounds were synthesized through the condensation reaction between trimethoprim with bromoacetic acid to yield compound 1. Several Schiff bases 2–7 have been synthesized by the condensation different aromatic aldehydes with compound 1. Compound 8 were formed from the reaction of sodium nitrite and acetyl acetone in presence of conc. hydrogen chloride to obtain the hydrazono derivative; then, Cyclocondensation of compound 8 with hydrazine hydrate, phenyl hydrazine and dinitrophenyl hydrazine respectively to yield compounds 9–11 in ethanol affording the pyrazoline derivatives. This work involves the synthesis of some 1,2,3-Triazoles derived from compound 1 by the action of sodium azide on the diazonium chloride salt to yield 5-azido-8-(3,4,5-trimethoxybenzyl)imidazo[1,2-c]pyrimidin-3(2H)-one 12. Finally, by reaction of 12 with acetyl acetone and ethyacetoacetate; respectively in sodium ethoxide/ethanol as a solvent to form compounds 13, 14. The structures of the compounds 1–14 were characterized by elemental analysis, spectral data and antimicrobial evaluation of the some newly synthesized compounds and found that the synthesized compounds are active against tested Gram positive and Gram negative bacteria like Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Proteus.     

Improved Calcium Ion-Selective Electrode Based on a Neutral Carrier

Abstract

The performance of a liquid-membrane electrode using a synthetic, neutral carrier in o-nitro-phenyl-n-octyl-ether as membrane component in a PVC matrix, in the presence of sodium tetra-phenyl-borate, is described. Selectivities, working range, lifetime and anion interference are discussed. The electrode makes possible the measurement of calcium ion activities in the range 10^?1M to 10^?6M in unbuffered and in the range 10^?1M to 10^?8M in calcium buffered systems respectively. The selectivities of calcium over protons, magnesium, sodium and zinc are 25,000, 26,000, 2,800 and 7,100, respectively, and are far superior than those reported for other calcium sensors.     

Resolving Agents. I. (R)-(-)-2-Amino-1-benzyloxybutane,a New Base for the Resolution of Racemic Acids

Treatment of the readily available (R)-(-)enantiomer of 2-aminobutan-1-ol 1 with sodium hydride followed by benzyl chloride afforded the O-benzyl base (R)-(-)-2. The latter was successfully used for the resolution of racemic α-methylsuccinic and α-bromosuccinic acids, as well as of the racemic α-benzylhemisuccinic esters 8 and 9 resectively.     

New reaction of the sodium salt of 2-nitroethanol. X-ray analysis of the sodium salt of 2-oxo-3-hydroxypropionic acid oxime, 2-bromo-2-nitropropane-1,3-diol,and the model 2,2-dinitropropane-1,3-diol

A novel reaction of the sodium salt of 2-nitroethanol in aqueous ammonia resulted in the sodium salt of 2-oxo-3-hydroxypropionic acid oxime (1) has been found. Bromination of1 affords 2-bromo-2-nitropropane-1,3-diol (2) with a previously unknown molecular conformation. The formation mechanisms of compounds1 and2 were suggested. X-ray analysis of products1,2 and that of the model compound, 2,2-dinitropropane-1,3-diol, was performed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1217–1221, May, 1996.     

Base induced cyclization of some quinolines. Formation of fused nitrogen heterocyclic ring system

Condensation of 3,5-dinitro-4-chloro-6-methoxy-2-methylquinoline (1) with benzylamine, ethanolamine and/or thioglycolic acid afforded the quinoline derivatives4 a-c. Cyclization of4 a and4 b with alkali and condensation of1 with glycine in sodium carbonate solution furnish 2H-imidazo[4,5-c]quinoline derivatives5 a-c, respectively. Treatment of5 b with benzaldehyde in presence of zinc chloride gave the styryl derivative6. 1 reacted with sodium azide to give the azido derivative4 d, which upon treatment with phenylhydrazine or sodium borohydride yielded the 4-amino derivative4 3. Moreover,1 was treated with phenylhydrazine to give4 f, which cyclized in 10% sodium hydroxide solution to the corresponding v-triazolo[4,5-c]quinoline 3-oxide derivative7. When however4 f was treated with dilute hydrochloric acid, the corresponding phenylpyrazolo[3,4,5-de]quinoline derivative8 was obtained.

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Baseninduzierte Cyclisierung einiger Chinoline. Darstellung höherer Stickstoff-Heterocyclen

Zusammenfassung Kondensation von 3,5-Dinitro-4-chlor-6-methoxy-2-methylchinolin (1) mit Benzylamin, Ethanolamin und/oder Thioglycolsäure ergab die Chinolinderivate4 a-c. Cyclisierung von4 a und4 b mit Alkali und Kondensation von1 mit Glycin in Natriumcarbonatlösung lieferte 2H-imidazo[4,5-c]chinolin-Derivate5 a-c. Behandlung von5 b mit Benzaldehyd in Gegenwart von Zinkchlorid ergab das Styrylderivat6. 1 wurde mit Natriumazid zum Azidoderivat4 d umgesetzt, das mit Phenylhydrazin oder Natriumborhydrid zum 4-Aminoderivat4 e weiterreagierte.1 ergab mit Phenylhydrazin4 f, das in 10% NaOH-Lösung zum entsprechenden Triazolo[4,5-c]chinolin-Derivat7 cyclisierte. Aus4 f wurde mit verdünnter Salzsäure das Phenylpyrazolo[3,4,5-de]chinolin8 erhalten.

     

Coordination of benzene to a sodium cation

The complexes Na(Et₂O)(dpp-BIAN)AlEt₂ (5) and Na(η⁶-C₆H₆)(dpp-BIAN)AlEt₂ (6) were synthesized by reactions of the disodium salts of dpp-BIAN (dpp-BIAN is 1,2-bis[(2,6-di-isopropylphenyl)imino]acenaphthene) with 1 equiv. of Et₂AlCl in diethyl ether and benzene, respectively. The structures of both complexes were established by X-ray diffraction. In molecules 5 and 6, diethylaluminum is chelated by the dianionic dpp-BIAN ligand. The sodium cations in molecules 5 and 6 are located above the plane of the diimine fragments and coordinate the Et₂O or benzene molecule, respectively. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1702–1707, September, 2007.     

SYNTHESIS OF α-AMINOORTHOESTERS FROM O-TOSYLHYDROXIMATES

ABSTRACT

The abstraction of the acid hydrogen of O-tosylhydroximates 1 by sodium ethylate, then nucleophilic attack of the excess of sodium ethylate at the more hindred carbond atom of azirine 2 and aziridine 3 intermediates to give the α-aminoorthoesters (35–45% yields). The α-aminoorthoester 4a is transformed into α-iminoorthoesters 5a (63% yield) and α-amidoorthoester 6a (65% yield).     

Preparation and Free-Radical Polymerization of 2,4-Dichloro-6-(p-Vinylphenyl)-1,3,5-triazine as a Reactive Monomer Containing Two Replaceable Groups

Abstract

A new monomer containing two replaceable groups, 2,4-dichloro-6-(p-vinylphenyl)-1,3,5-triazine (DCVT) was prepared by the reaction of p-vinylphenylmagnesium chloride with cyanuric chloride. This monomer was polymerized readily in benzene by AIBN at 60°C. From the copolymerization with styrene, Q and e values of DCVT were obtained as Q = 2.42 and e = 0.08. An insoluble terpolymer prepared from DCVT, styrene, and divinylbenzene was treated with several nucleophilic reagents, including sodium methoxide, sodium methylmercaptide, dimethylamine, and triethylphosphite, to afford the corresponding polymers in high conversions.