Ethoxide In Ethanol Research Articles

Studies on isocyanides: synthesis of tetrazolyl-isoindolinones via tandem Ugi four-component condensation/intramolecular amidation

The Ugi four-component condensation between methyl o-formylbenzoates 1, anilines 2a– c, isocyanides 3, and trimethylsilyl azide ( 4) afforded the expected Ugi adducts 5a– d, which were cyclized to the title compounds 6a– d upon treatment with sodium ethoxide in ethanol. Starting from aralkyl- or alkylamines 2d– g the Ugi adducts underwent a spontaneous cyclization to tetrazolyl-isoindolinones 6e– j.

Holzapfel-Meyers-Nicolaou Modification of the Hantzsch Thiazole Synthesis

Modified conditions for Hantzsch thiazole synthesis provides valine- and threonine-derived thiazoles without significant loss of optical purity. This two- or three-step procedure proceeds by the cyclocondensation of the corresponding thioamide under basic conditions, according to modified methods of Meyers and Holz­apfel. The hydroxythiazoline intermediate is then dehydrated by treatment with trifluoroacetic anhydride-pyridine, followed by triethylamine, according to Nicolaou’s procedure. Solvolysis of the trifluoroacetamide derivative produced in this process can be affected with sodium ethoxide in ethanol to give a reliable method for the stereoselective synthesis of functionalised thiazole building blocks in high yield.

Sol–gel processing of IrO2–TiO2 mixed metal oxides based on a hexachloroiridate precursor

Mixed IrO2–TiO2 oxides were prepared by the sol–gel method upon acid-catalysed hydrolysis of an iridium solution in ethanol mixed with titanium tetraethoxide in ethanol. The iridium solution was obtained by reaction of the sodium hexachloroiridate(IV) precursor in the presence of sodium ethoxide in ethanol. Gels were formed in all but the high-Ir samples. Analysis of the dried gels showed minority-phase enrichment at the surface and the presence of Ir(III), while microscopy showed evidence for dispersed iridium-containing nanoparticles (1–20 nm in diameter). XRD powder patterns of the calcined material showed peaks due to a small amount of crystalline NaCl impurity which could be removed by washing. This left amorphous phases, except in the Ir:Ti 3:2 case, which showed evidence for the presence of separate crystalline oxide phases: anatase, IrO2 and TixIr1−xO2.

Ring transformations of heterocyclic compounds. XXV. Phenanthrene aldehyde imines via ring transformation of pyrylium salts with methylenedihydroisoquinolines—A novel access to the phenanthrene skeleton

Abstractmagnified imageThe ring transformation of 2,4,6‐triarylpyrylium salts 1 with 2‐methylenedihydroisoquinolines 6, generated in situ from the related 2‐methylisoquinolinium salts 2, in the presence of bases is reported. Whereas the transformation of 1 with 2(6) and sodium methoxide in methanol leads to 2‐(2,4,6‐triarylphenyl)isoquinolinium salts, with sodium ethoxide in ethanol the aryl substituted phenanthrene‐9‐carbaldehyde imines 4 are obtained, the structure of which was confirmed by an X‐ray structure determination of the 1‐(4‐methylphenyl) substituted derivative. Acid catalyzed hydrolysis of the imines 4 gives rise to the parent phenanthrene aldehydes. The transformation 1 + 2(6) → 4 represents a novel access to the phenanthrene skeleton.

First example of 5/6-O-linked pseudosaccharides: synthesis of bicyclic nucleosides containing azido or extended carbohydrate moiety

Treatment of the d-glucose-derived substrate 1 with sodium hydride in tetrahydrofuran provided 3,6-anhydro monosaccharide 2, along with the 5,6-ether linked pseudodisaccharide 3, and pseudotrisaccharide 4. However, reaction of 1 with sodium ethoxide in ethanol afforded 2 as the sole product, elaborated to the bicyclic azidonucleosides 9 and 16. Acetylated bicyclic nucleosides 17– 19 with extended carbohydrate residues have been synthesized from 3.

Nb‐Doped VO2 Thin Films Prepared by Aerosol‐Assisted Chemical Vapour Deposition

AbstractNiobium‐doped vanadium dioxide (VxNb1–xO2, x = 0–0.037) thin films were prepared by aerosol‐assisted chemical vapour deposition (AACVD) of vanadyl(IV) acetonate and niobium(V) ethoxide in ethanol. Samples were analysed by EDX, XRD, Raman, XPS and SEM. The analyses confirmed the deposition of niobium, even if no separated phase was formed; the morphological structure of the films was affected by the dopant presence. The thin films showed thermochromic behaviour, with a marked change in optical properties above and below the switching temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Tungsten trioxide thin films prepared by electrostatic spray deposition technique

Tungsten trioxide (WO3) thin films deposited on a Pt-coated alumina substrate using the electrostatic spray deposition (ESD) technique is reported in this paper. As precursor solution, tungsten (VI) ethoxide in ethanol was used. The morphology and the microstructure of the films were studied using scanning electron microscopy coupled with energy dispersive X-ray analysis, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Dense to porous morphologies were obtained by tuning the deposition temperature. Impedance spectroscopy and current–voltage measurements were used to study the electrical behaviour of the films in air, in temperature range 300–500 °C. The activation energy was estimated from Arrhenius plots. Considering the obtained results, the ESD technique proved to be an effective technique for the fabrication of porous tungsten trioxide thin films.

Preparation and Characterization of Nanomaterials of Tellurium, Bismuth, and Bismuth Telluride

Abstract In order to improve the processing and performance of tellurium (Te), bismuth (Bi), and bismuth telluride (dibismuth tritelluride, Bi2Te3), which are valuable thermoelectric materials that operate near room temperature in the bulk state, a nanometer scale synthetic method, in which the starting materials are reduced with NaBH4 in the presence of protecting agents in solution under mild conditions, was used. Te nanorods having an average diameter of 10 ± 3 nm (aspect ratio = 3.0) were prepared by reducing tellurium(IV) ethoxide in ethanol in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) under nitrogen. Although Bi nanoparticles prepared from bismuth(III) chloride by this method have an average diameter of 29 ± 8 nm, PVP-protected Bi2Te3 nanoparticles have a really small average diameter (7 ± 5 nm) and they are probably the smallest Bi2Te3 particles ever reported. Heat treatment of PVP-protected Bi2Te3 nanoparticles in refluxing solvents was found to improve the stability.

Efficient Catalytic Asymmetric Synthesis of trans‐5‐Aryl‐2‐substituted Cyclohexanones by Rhodium‐Catalyzed Conjugate Arylation of Racemic 6‐Substituted Cyclohexenones

AbstractCatalytic asymmetric conjugate arylation of racemic 6‐substituted cyclohexenones with arylboronic acids was catalyzed by 3 mol % of chiral amidophosphane‐[RhCl(C2H4)]2 in a 10:1 mixture of 1,4‐dioxane and water at 70 °C to afford a nearly 1:1 mixture of trans‐ and cis‐5‐aryl‐2‐substituted cyclohexanones in high enantioselectivity, which was subsequently epimerized with sodium ethoxide in ethanol to give thermodynamically stable trans‐5‐aryl‐2‐substituted cyclohexanones with 99–97 % ee in high two‐step yields.

New isomers of 4,1-benzothiazepines. The first evidence for the desmotropy of seven-membered heterocycles

A novel procedure was developed for the preparation of 2,3-disubstituted 4,1-benzothiazepines, via the ring transformation of (2 R ∗,2a S ∗)-2-chloro-2a-phenyl-2,2a-dihydro-2 H,4 H-azeto[1,2- a][3,1]benzothiazin-1-one ( 1) with sodium ethoxide in ethanol. The tautomeric products ( R ∗)-3-ethoxycarbonyl-2-phenyl-3,5-dihydro-4,1-benzothiazepine ( 4) and 3-ethoxycarbonyl-2-phenyl-1,5-dihydro-4,1-benzothiazepine ( 5) exhibit the rare phenomenon of desmotropy of the condensed seven-membered heterocycles. Surprisingly, these desmotropes could be separated by column chromatography. The products are unexpectedly stable in solution and their structures were proved by means of NMR and mass spectrometry.

Synthesis of 3-Hydroxy-6-oxo[1,2,4]triazin-1-yl Alaninamides, a New Class of Cyclic Dipeptidyl Ureas

Cyclohexyl or benzyl isocyanide, benzoyl-, or 4-methoxybenzoylformic acid and semicarbazones underwent Ugi reactions in methanol for 3 days to give the Ugi adducts, which were then stirred with sodium ethoxide in ethanol for 12 h to give 3-hydroxy-6-oxo[1,2,4]triazin-1-yl alaninamides. The X-ray diffraction structure of the first example showed the tautomer having the proton in the O2 atom that was fixed in the crystal by packing in dimers with a H-bond distance of 1.9 A. Selected [1,2,4]triazines were treated with diazomethane for 12 h to get the O-methyl derivatives. Both hydroxy and O-methyl derivatives obtained by this method constitute a new class of pseudopeptidic [1,2,4]triazines composed of two different amino acids, arylglycine and alanine derivatives, in which the N-terminal arylglycine and the peptidic amide nitrogen atoms are bonded through a urea moiety.

Self‐Assembly of Dialkyltin Moieties and Mercaptobenzoic Acid into Macrocyclic Complexes with Hydrophobic “Pseudo‐Cage” or Double‐Cavity Structures: Supramolecular Infrastructures Involving Intermolecular CH⋅⋅⋅S Weak Hydrogen Bonds and π–π Interactions

Four novel organotin complexes of two types--[R2Sn(o-SC6H4CO2)]6 (R = Me, 1 x H2O; nBu, 2) and {[R2Sn(m-CO2C6H4S)R2Sn(m-SC6H4CO2)SnR2]O}2 (R = Me, 3; nBu, 4)--have been prepared by treatment of o- or m-mercaptobenzoic acid and the corresponding R2SnCl2 (R = Me, nBu) with sodium ethoxide in ethanol (95%). All the complexes were characterized by elemental analysis, FT-IR and NMR (1H, (3C, 119Sn) spectroscopy, TGA, and X-ray crystallography diffraction analysis. The molecular structure analyses reveal that both 1 and 2 are hexanuclear macrocycles with hydrophobic "pseudo-cage" structures, while 3 and 4 are hexanuclear macrocycles with double-cavity structures. Furthermore, the supramolecular structure analyses show that looser and more intriguing supramolecular infrastructures were also found in complexes 1-4, which exist either as one-dimensional chains of rings or as two-dimensional networks assembled from the organometallic subunits through intermolecular C-H...S weak hydrogen bonds (WHBs) and pi-pi interactions.

Crystal structure of N-benzy 1-N- 1,3,4-tetramethyl- 2,5-dioxo-4-imidazolidinecarboxamide, C15H19N3O3

C15H19N3O3, monoclinic, P\2\!c (no. 14), a = 16.837(8) A, b = 7.368(4) A, c = 13.070(7) Ks= 11.005(4)°, V= 1513.7 A, Z = 4, Rgt(F) = 0.050, wRnf(r) = 0.120, T= 295 K. Source of material Reaction of diethyl 2-acetylamino-2-methylmalonate with benzylurea and sodium ethoxide in ethanol at 120 °C over 4 h according to [1] and purification of the crude product by column chromatography yielded N-benzyl-4-methyl-2,5-dioxo-4imidazolidinecarboxamide. Following alkylation with an excess of methyl iodide and sodium hydride in dry dimethylformamide for4h at 78 °C gave A^-benzyl-A/-l,3,4-tetramethyl-2,5-dioxo-4imidazolidinecarboxamide as an oil. Crystals were obtained by dissolution in dimethyl sulfoxide and slow evaporation of the solvent over a period of several months. Experimental details All hydrogen positions were localized by Fourier difference calculations and individually refined with respect to positions and isotropic thermal displacement parameters. Discussion The structure contains one molecule per asymmetric unit and is held together by Van der Waals forces. All intramolecular bond lengths are normal. The shortest intermolecular distances are d(07-• H093-C9) = 2.576(1) A and </(011-H132-C13) = 2.760(1) A. The main part of the molecule consists of an almost planar ring system (N1, C2, N3, C4, C5, C6,07, C8,021) with an r.m.s. value of the deviations from the least squares plane of 0.036 A. A second plane, defined by the benzyl group (C14 C20) with r.m.s. = 0.009 A, is tilted by 66.8(1)° against the first mentioned plane. Both planes are connected by C10 and Ν12, which form together with (C4, C9, Ol 1, C13, C14) an almost planar third plane with r.m.s. = 0.07 A, tilted by 85.2(1)° against the first one and by 63.4(1)° against the second one. Table 1. Data collection and handling.

Facile entries for regioselective synthesis of [1,2,4]triazolo-[4,3-a]pyrimidin-5(1H)-ones from 2-thiouracil

Three new alternative synthetic strategies based on reactions of hydrazonoyl halides 3 with 2-methylthiouracil 2 and treatment of either 2-pyrimidinyl thiohydrazonates 8 or the diazonium coupling products of active (pyrimidin-2-ylthio)methylene compounds 12 with sodium ethoxide in ethanol are described for the title compounds. The mechanisms and regiochemistry of the studied reactions are discussed.

Synthesis and Reactions of Some New Thienopyrimidines

4-Methyl-6-mercapto-2-phenylpyrimidine-5-carbonitrile ( 1 ) was reacted with different halo compounds, namely ethylchloroacetate, chloroacetone, bromoacetanilide, p-chlorobromoacetanilide, and p -methoxy chloroacetanilide in ethanol in the presence of sodium acetate yielded the corresponding S-alkylated derivatives ( 2a-e ). The latter compounds underwent cyclization into thienopyrimidines ( 4a-e ) upon treatment with sodium ethoxide in ethanol. The reaction of ( 4a ) with hydrazine hydrate led to the formation of 5-amino-4-methyl-2-phenylthieno[2,3-d]pyrimidine-2-carbohydrazide ( 5 ). Compound ( 5 ) was reacted with a variety of reagents to produce other new thienopyrimidines as well as oxadiazolylthienopyrimidines ( 6, 11 ).

Synthesis of Some Heterocycles of Expected Biological Activity Through the Action of Isatin-3-Thiosemicarbazone on Acetylenic Ketones and Esters

Isatin-3-thiosemicarbazone ( 1 ) reacted with 1-aryl-3-phenylprop-2-yn-1-ones ( 2a-c ) in n-butanol to give 4-aryl-6-phenyl-2-[2-oxo-2H,3H-benzo(b) pyrrolidine-3-iminyl]-imino-2H-1,3-thiazines ( 3a-c ). Similar treatment of 1 with acetylenic esters ( 4a-c ) gave the 6-substituted derivatives of 2-imino-3-[2-oxo-2H,3H-benzo(b)pyrrolidine-3-iminyl]-2,3-dihydro-4-oxo-1,3-thiazine ( 5a-c ). Treatment of 1 with 4a-c in the presence of sodium ethoxide in ethanol gave the 6-substituted derivatives of 3-[2-oxo-2H,3H-benzo(b)pyrrolidine-3-iminyl]-4-oxo-2-thioxo-1,2,4-trihydropyrimidine ( 6a-c ). However, when 1 was refluxed with 1-p-chlorophenyl-3-phenylprop-2-yn-1-one ( 2b ) in ethanol it gave a mixture of 2,4,6-tris[2-oxo-2H,3H-benzo(b)pyrrolidine-3-iminyl] amino-1,3,5-triazine ( 7 ) and Z,Z-3,3'-thiodi(1-p-chlorophenyl-3-phenylprop-2-en-1-one) ( 8 ). The aziridine imine derivative ( 9 ) and the pyrazole derivatives ( 10a and b ) were the only isolated products upon treatment of 3c , 6a , and 6c and 3a and 3b with hydrazine hydrate, respectively. Structures of all new compounds are evidenced by microanalytical and spectral data.

An improved method for cysteine alkylation

An improved method for the synthesis of S-alkylated cysteine derivatives with branched alkyl chains is reported. These compounds can be obtained in good yield and high purity by refluxing the cysteine thiol with the appropriate alkyl bromide in a solution of sodium ethoxide in ethanol.

UNPRECEDENTED OUTCOME OF BASE-PROMOTED NEBER REARRANGEMENT OF O-MESYLOXIME OF 2-ARYL-1,2,3,4-TETRAHYDRO-1-METHYLSUL FONYL-4-QUINOLONE- SYNTHESIS OF 4-AMINO-2-ARYLQUINOLINES

O-Mesyloximes derived from 2-aryl-1,2,3,4-tetrahydro-1-methylsulfonyl-4-quinolones react with sodium ethoxide in ethanol to afford the 4-amino-2-arylquinolines in high yield. No traces of the 3-amino-2-aryl-4-quinolones expected from the Neber rearrangement of the substrates were detected or isolated from the reaction mixture. The structures of the products were determined using a combination of 1H NMR, 13C NMR, IR and mass spectroscopic techniques.

ChemInform Abstract: Ethanolysis of 4‐(N,N‐Dimethylaminomethylene)‐2‐aryl‐2‐oxazolin‐5‐ones with Sodium Ethoxide in Ethanol at Reflux Temperature: Unusual Formation of N‐Acyl‐α‐amino Acids.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Chalcogenopyranones from disodium chalcogenide additions to 1,4‐pentadiyn‐3‐ones. The role of enol ethers as intermediates

AbstractEnol ethers 9 are formed as a mixture of E‐ and Z‐isomers from the addition of ethanol to 1,4‐pentadiyn‐3‐ones 2 in sodium ethoxide/ethanol. The enol ethers react with disodium chalcogenides to give the corresponding 2,6‐disubstituted chalcogenopyranones 1 bearing alkyl, aryl, or heteroaryl substituents in high yield as the only heterocyclic product of reaction. Diynones 2 react with disodium chalcogenides to give mixtures of products in which the chalcogenopyranones 1 are minor components and the dihydrochalcogenophenes 3 are the major products. The addition of hydrogen sulfide to diynone 2b in ethanol gives a product mixture nearly identical to that observed for the addition of disodium sulfide in sodium ethoxide in ethanol to 2b. Intermediates for the addition of hydrogen chalcogenides and disodium chalcogenides to both 2 and 9 are described, which lead to the heterocyclic products.