Category: 5182-90-1

Marques-Gallego, Patricia; Gamiz-Gonzalez, M. Amparo; Fortea-Perez, Francisco R.; Lutz, Martin; Spek, Anthony L.; Pevec, Andrej; Kozlevcar, Bojan; Reedijk, Jan published the artcile< Quinoxaline-2-carboxamide as a carrier ligand in two new platinum(II) compounds: Synthesis, crystal structure, cytotoxic activity and DNA interaction>, Computed Properties of 5182-90-1, the main research area is crystal structure platinum quinoxalinecarboxamide chloro solvent complex; platinum quinoxalinecarboxamide chloro solvent preparation DNA binding unwinding cytotoxicity; ethylguanine substitution platinum quinoxalinecarboxamide chloro solvent DNA model; antitumor platinum quinoxalinecarboxamide chloro solvent complex.

The search for platinum compounds structurally different from cisplatin has led to two new platinum(II) compounds containing quinoxaline-2-carboxamide as a carrier ligand, i.e. cis-[Pt(qnxca)(MeCN)Cl2] (1) and the [Pt(qnxca-H)(DMSO)Cl] (2). Both compounds have been synthesized and characterized using different spectroscopic methods. In addition, single-crystal structures have been determined by X-Ray diffraction for both compounds In each case a square planar Pt(II) is present; in (1) the qnxca is monodentate and neutral, whereas in (2) the ligand has lost a hydrogen, to form the anionic chelating ligand abbreviated as qnxca-H. The biol. activity of both compounds has been investigated in a panel of seven human tumor cells, displaying poor cytotoxic activity, compared to cisplatin. The interaction of the new compounds with 1 or 2 equivalent of 9-ethylguanine has been studied using 1H NMR, 195Pt NMR and ESI-MS spectroscopy, finding poor reactivity of 1 towards the model base, forming only the monosubstituted adduct. Surprisingly, compound 2, which is more sterically crowded, interacts more efficiently with the 9-EtG, forming a bifunctional adduct with two 9-EtG with substitution of the DMSO and the chloride ligand. Unwinding studies of pUC19 plasmid DNA by compound 1 show similar unwinding properties to cisplatin.

Dalton Transactions published new progress about Antitumor agents. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, Computed Properties of 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Minisci, Francesco; Citterio, Attilio; Vismara, Elena; Giordano, Claudio published the artcile< Polar effects in free-radical reactions. New synthetic developments in the functionalization of heteroaromatic bases by nucleophilic radicals>, Related Products of 5182-90-1, the main research area is lepidine alc nucleophilic radical substitution; hydroxylaminium salt titanium substitution catalyst; hydroxyalkyllepidine; substitution catalyst benzoyl peroxide hydrogen; carbamoylation quinoline acridine pyrazine benzothiazole; heteroaromatic base carbamoylation peroxide catalyst; dioxane hydrofuran lepidine radical substitution.

Direct substitution of protonated heteroaromatic bases by nucleophilic carbon-centered radicals involved use of the redox system N+H3OH/Ti(III) in several solvents, use of benzoyl peroxide in alcs., and carbamoylation by HCONH2 and H2O2 in the presence of catalytic Fe(II). Thus lepidine I (R = H) in MeOH gave 98% I (R = CH2OH) in the presence of benzoyl peroxide. These systems gave hitherto unobtainable substitution products and reactions of industrial interest. Polar effects determine reactivity, selectivity and synthetic applications; in particular the role of the strongly nucleophilic intermediate radicals of pyridinyl type in the rearomatization step is emphasized.

Tetrahedron published new progress about Carbamoylation. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, Related Products of 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Otsuka, H.; Shoji, J. published the artcile< Structure of triostin C>, Reference of 5182-90-1, the main research area is .

Triostin antibiotics from a streptomyces related to Streptomyces aureus gave a mixture of components C and A. The mixture (600 mg.) chromatographed on silica gel and eluted with CHCl3-MeOH solutions containing increased concentrations of MeOH from 0-3% and with control by observation of optical densities at 243 mμ, the antibiotic fractions examined by thin-layer chromatography on Al2O3 (solvent, lower layer of 3:1:3 EtOAcCl2CHCHCl2-H2O) and the concentrates containing component C crystallized from CHCl3-MeOH gave 280 mg. triostin C (I), decomposing above 260°, [α]24D -143.9 ± 2° (c 1.121, CHCl3), mol. weight 1125 (Barger-Niederl, CHCl3), 1120 (osmometry, CHCl3). I hydrolyzed 20 hrs. in 6N HCl at 105° and the hydrolysate examined by 2-dimensional paper chromatography gave 4 ninhydrin pos. substances, Rf in 4:1:2 BuOH-AcOH-H2O (and H2O-saturated PhOH): N,N’-dimethylcycstine (II) 0.18 (0.84); alanine (III) 0.36 (0.56); N,γ-dimethylalloisoleucine (IV) 0.74 (0.92); serine (V) 0.26 (0.37). When developed with a collidine-containing MeOH ninhydrin solution (CA 59, 9550a) the spots were brownish-purple, purple, brownish-purple, and grayish-purple. II and IV gave red spots with p-O2NC6H4COCl-C5H5N, indicative of N-alkyl amino acids, and II gave also a red spot with Na2Fe(CN)5NO.2H2O-NaCN. The total acid hydrolysate from 500 mg. I concentrated and extracted with H2O, chromatographed on cellulose and eluted with 4:1:2 BuOH-AcOH-H2O gave in order IV, III, V, II. Similar chromatographic separation on Dowex 50 W × 4 and elution with 0.2M C5H5N-HCO2H (pH 2.80) gave II, V, IV and III in order with partial overlap. The individual acids were isolated by decolorization of the fractions with C and recrystallization to give V, m. 220-5° (decomposition) (H2O-EtOH), [α]24D -14.6 ± 2° (c 0.994, 1.0N HCl); L-III, m. 280-2° (decomposition) (H2O-EtOH), [α]23D 12.1 ± 4° (c 0.626, 1.0N HCl); II, gel-like and difficult to purify, m. 175-82° (decomposition), [α]26D 22.7 ± 2° (c 1.049, 1.0N HCl), [α]25D 34.0 ± 2° (c 1.022, 1.0N HCl), ir spectrum identical with that of synthetic compound, m. 215-17° (decomposition), [α]25D 58.1 ± 2° (c 1.00, 1.0N HCl); L-IV, m. 300°, [α]25.5D 28.4 ± 2° (c 0.937, H2O), 41.9 ± 2° (c 1.049, 5N HCl). II (10 mg.) in 2 ml. H2O stirred 2 hrs. at 45° with 300 mg. Raney Ni and the combined filtrate and H2O-washings examined by paper chromatography on 4:1:2 BuOH-AcOH-H2O, H2O-saturated iso-Pr CH2OH, H2O-saturated Me2CCH2OH, H2O-saturated PhCH2OH, and H2O-saturated PhOH showed Rf values of 0.40, 0.22, 0.06, 0.15, and 0.84 resp., identical with those of synthetic DL-MeCH(NHMe)CO2H. I (500 mg.) partially hydrolyzed in concentrated HCl at 37° 2 days and extracted with EtOAc, the aqueous layer examined for amino acids and the decolorized extract chromatographed on paper with BuOH saturated with 3% aqueous NH4OH as solvent gave quinoxaline-2-carboxylic acid (VI), m. 210-11° (decomposition), ir spectrum identical with that of synthetic VI. I (4.100 mg.) in 0.5 ml. 6N HCl heated 72 hrs. at 105° in an evacuated sealed tube and the hydrolysate submitted to amino acid analysis showed the presence per mole I of 1.48 moles V, 2.02 moles III, 2.16 moles half II, and 2.14 moles IV. A larger amount of V was obtained under milder conditions of hydrolysis. I (2.160 mg.) heated 20 hrs. in 0.3 ml. 5N NaOH at 105° and adjusted with Dowex 50 W (H type) to pH 8.2, acidified with dilute HCl and analyzed gave 0.083 moles V, 1.98 moles III, 1.67 moles IV, and 0.74 mole NH3 per mole I. Extraction of a portion of the hydrolysate with EtOAc gave VI. I (100 mg.) in 6 ml. 90% MeOH containing 0.1N Na0H stirred 2 hrs. at 25° and diluted with 40 ml. H2O, adjusted to pH 2.0 and extracted with EtOAc, transferred into 15 ml. 5% NaHCO3 and reextracted with EtOAc at pH 2.0, the washed extract concentrated and diluted with C6H14 gave 93 mg. alkali-treated triostin C (VII), m. 159-62°, mol. weight 1300 (osmometry, CHCl3), 1000-1300 (Barger-Akiya, Me2CO), pKa 5.7, giving only 0.065 mole V, 1.98 moles III, 2.04 moles half II, 2.06 moles IV, and 2.32 moles NH3 in acid hydrolysis, suggesting the formation of a dehydroalanine derivative by β-elimination reaction on the O-substituted serine residue caused by alkali treatment. VII (15 mg.) heated 3 hrs. at 100° in 0.5 ml. 3N HCl gave 1.8 mole pyruvic acid as determined as its 2,4-dinitrophenylhydrazone, m. 218-20° (MeOH-H2O). VII in 1:1 dioxane-H2O boiled at pH 2.0 released quinoxaline-2-carboxamide, m. 204.5-5.5°. Dakin-West degradation of VII showed that IV was the C-terminal amino acid. VII dinitrophenylated and submitted to acid hydrolysis failed to give dinitrophenylated amino acids, indicating that VI was attached to N-terminal amino acid. Accordingly a lactone linkage was presumed to exist in I. CrO3 oxidation of I did not destroy V, indicating that the OH group of V was involved in the lactone linkage. I (100 mg.) in 2 ml. HCO2H kept 16 hrs. at 0° with 20 ml. performic acid reagent according to Thompson (CA 49, 4748a) and the mixture diluted with 80 ml. H2O, freeze-dried and the residue extracted with MeOH, precipitated with Et2O and the 80 mg. hygroscopic powder analyzed showed the presence of III, IV, V, and N-methylcysteic acid (VIII). I (100 mg.) in 15 ml. 4:1 dioxane-H2O stirred 4.5 hrs. with 1.0 g. Raney Ni W-2 at 80-90° and the filtered solution and washings evaporated, the residue extracted and the extract diluted with C6H14 gave 68 mg. dethiotriostin C (IX), m. 183-6° (decomposition), mol. weight 940, 1000-1300, hydrolyzed to give 1.48 moles V, 1.90 moles III, 2.00 moles N-methylalanine (X), and 1.99 moles IV. I gave no reaction with Na2Fe(CN)5NO-NaCN reagent but a pos. reaction for the disulfide bond was obtained following treatment with cold, dilute NaOH with opening of the lactone ring and increasing solubility The mol. weight determination of IX confirmed a proposed partial formulation and it remained to elucidate the amino acid sequence between IV and V. IX was partially hydrolyzed by concentrated HCl at 37° 2 days and the hydrolysate extracted with BuOH to sep. chromophore and simple peptide fragments. The chromophore peptides, characterized by uv absorption, were separated on a 2-dimensional paper chromatogram in BuOH saturated with aqueous NH4OH followed by 1.5M phosphate buffer, pH 5.0, giving N-(quinoxaline-2-carboxyl)serine and N-(quinoxaline-2-carboxyl)serylalanine, N-(quinoxaline-2-carboxyl)-O-(N,γ-dimethylalloisoleucyl)serine and N-(quinoxaline-2-carboxyl)-O-(N,γ-dimethylalloisoleucyl)serylalanine. As simple peptide fragments, serylalanine and serylalanyl-N-methylalanyl-N,γ-dimethylalloisoleucine were separated by paper chromatography in BuOH-AcOH-H2O followed by H2O-saturated phenol. Similar acid hydrolysis with I gave another 2 peptide fragments consisting of V, III and N,N’-dimethylcystine. It was concluded that I has the proposed structure. There are 2 series of quinoxaline antibiotics; one has a dithiane ring as in echinomycin, and the other contains an N,N’-dimethyl residue. Each series involves several antibiotics differing only in their N-methylamino acid constituents.

Tetrahedron published new progress about 5182-90-1. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, Reference of 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Huang, Yao; Chen, Tieqiao; Li, Qiang; Zhou, Yongbo; Yin, Shuang-Feng published the artcile< Copper catalysed direct amidation of methyl groups with N-H bonds>, Reference of 5182-90-1, the main research area is methyl group amidation copper catalyst.

An efficient copper catalyzed direct aerobic oxidative amidation of Me groups of azaarylmethanes with N-H bonds producing amides is successfully developed, which can produce primary, secondary and tertiary amides, including those with functional groups. This reaction represents a straightforward method for the preparation of amides from the readily available hydrocarbon starting materials.

Organic & Biomolecular Chemistry published new progress about Amidation. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, Reference of 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Tymoshenko, D. O. published the artcile< Quinoxalines (update 2012)>, Electric Literature of 5182-90-1, the main research area is review quinoxaline preparation.

A review of the synthetic approaches to quinoxaline and related systems.

Science of Synthesis, Knowledge Updates published new progress about Organic synthesis. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, Electric Literature of 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Lewis, Susan J.; Mirrlees, Margaret S.; Taylor, Peter J. published the artcile< Rationalizations among heterocyclic partition coefficients. Part 2: The azines>, SDS of cas: 5182-90-1, the main research area is azine structure partition coefficient; LFER azine.

π-Values (partition substituent constants) of 246 azines are given and discussed in terms of Δπ, the difference in π-value from that expected for C6H6. It is shown that Δπ is close to zero for alkyl and most halogen groups, but for polar substituents capable of H bonding it may be as high as φ1.6. Except for peri-positions, these Δπ-values may be correlated by a set of equations specific for different types of substituent position and containing terms which sep. parameterize proton-donor and -acceptor ability. The rationale behind this treatment is justified in terms of the nature of the octanol-H2O partitioning process and the manner in which electronic effects are expected to operate, in this context and that of the individual mol. Other topics discussed include: reasons for deviations among “”irregular”” substituents; the special problems of peri-positions; multisubstitution; and some consequences of this anal. for other types of compound

Quantitative Structure-Activity Relationships published new progress about Molecular structure-property relationship, partition. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, SDS of cas: 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Gobec, S.; Urleb, U. published the artcile< Product class 15: quinoxalines>, Electric Literature of 5182-90-1, the main research area is review quinoxaline preparation cyclization ring transformation aromatization.

A review. Methods for preparing quinoxalines are reviewed including cyclization, ring transformation, aromatization, and substituent modification.

Science of Synthesis published new progress about Aromatization. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, Electric Literature of 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Izzo, Francesca Caterina; Vitale, Valentina; Fabbro, Chiara; Van Keulen, Henk published the artcile< Multi-analytical investigation on felt-tip pen inks: Formulation and preliminary photo-degradation study>, COA of Formula: C9H7N3O, the main research area is photodegradation felt tip pen ink archaeol.

We present a multi-anal. study on the formulation of com. felt-tip pens, introduced in the second half of the 20th century and commonly used by modern and contemporary artists. These media of both drawing and writing have not yet been fully investigated, but the degradation processes they might undergo, such as fading, are well-known and rather apparent.Twelve water-based felt-tip pens were investigated by the joint use of complementary anal. techniques, such as Thin Layer Chromatog., NMR, Fourier transformed IR spectroscopy, X-ray fluorescence spectrometry and Pyrolysis-Gas Chromatog./Mass Spectrometry.The obtained results provided crucial, preliminary data for the identification of dyes, solvents and additives present in the inks’ formulations. Numerous synthetic food coloring agents and pigments were identified, such as Acid Yellow 23, Acid Red 18, Acid Blue 9, and Pigment Blue 15. In addition, glycols, fatty acids, 2-phenoxyethanol, colophony, benzotriazole derivatives and other solvents and additives were detected in the manufactured inks.Furthermore, the effects of photo-degradation on one emblematic ink sample were studied, highlighting in particular visual and aesthetical changes due to discoloration.This study demonstrates a methodol. based upon the use of an integrated anal. approach for the characterization of com. ink-based artistic media and their viable degradation patterns, which aims to develop suitable conservation treatments to assess modern and contemporary drawings and writings.

Microchemical Journal published new progress about Archaeology. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, COA of Formula: C9H7N3O.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Caronna, Tullio; Gambarotti, Cristian; Mele, Andrea; Pierini, Monica; Punta, Carlo; Recupero, Francesco published the artcile< A green approach to the amidation of heterocyclic bases: the use of sunlight and air>, Recommanded Product: Quinoxaline-2-carboxamide, the main research area is green chem amidation heterocyclic base sunlight.

A easy and environmentally friendly method for the photochem. functionalization of the heterocyclic bases is described. The selective introduction of the amido group of formamide, using sunlight and air in the presence of TiO2, has allowed to obtain the desired products in mild conditions with high conversions. The comparison of these results with those previously reported, in the presence of H2O2 instead of air, clarifies some aspects of the reaction mechanism.

Research on Chemical Intermediates published new progress about Amidation. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, Recommanded Product: Quinoxaline-2-carboxamide.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

He, Zeng-Yang; Huang, Chao-Fan; Tian, Shi-Kai published the artcile< Highly Regioselective Carbamoylation of Electron-Deficient Nitrogen Heteroarenes with Hydrazinecarboxamides>, SDS of cas: 5182-90-1, the main research area is regioselective carbamoylation electron deficient nitrogen heteroarene hydrazinecarboxamide copper catalysis.

The use of hydrazinecarboxamides as a new class of carbamoylating agents has been established through the dehydrazinative Minisci reaction of electron-deficient nitrogen heteroarenes. A wide range of electron-deficient nitrogen heteroarenes, including isoquinoline, quinoline, pyridine, phenanthridine, quinoxaline, and phthalazine, underwent copper/acid-catalyzed oxidative carbamoylation with hydrazinecarboxamide hydrochlorides to afford structurally diverse nitrogen-heteroaryl carboxamides as single regioisomers in moderate to excellent yields. The functional group tolerance was substantially demonstrated in the direct carbamoylation of quinine obviating multistep sequences involving protecting groups and prefunctionalization of the heterocycle.

Organic Letters published new progress about Aromatic nitrogen heterocycles Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, SDS of cas: 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider