Tag: 100-200

Selective Functionalization of Benzo-Fused N-Heterocycles by Using In Situ Trapping Metalations was written by Nishimura, Rodolfo H. V.;Murie, Valter E.;Vessecchi, Ricardo;Clososki, Giuliano C.. And the article was included in ChemistrySelect in 2020.Computed Properties of C8H5ClN2 This article mentions the following:

Some benzo-fused N-heterocycles, e.g., I were prepared by regioselective metalation of quinoline, isoquinoline, quinoxaline and quinazoline with LiTMP in the presence of zinc chloride. Applying this strategy to synthesize an analog of the antitumor verubulin illustrated its relevance for medicinal chem. Computational calculations of the pKa values of the aromatic hydrogens helped to rationalize substrate reactivity and metalation regioselectivity by the complex-induced proximity effect concept. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1Computed Properties of C8H5ClN2).

6-Chloroquinoxaline (cas: 5448-43-1) belongs to quinoxaline derivatives. Compounds possessing quinoxaline derivatives were bestowed with a variety of significant biological properties such as antiviral, antimalarial, anticancer, DNA intercalation, DNA duplex stabilization, and many others. Quinoxalines are used as dyes, pharmaceuticals, and antibiotics such as echinomycin, levomycin exhibiting antitumoral properties. Quinoxalines establish also the basis of anthelmintics and receptor antagonists.Computed Properties of C8H5ClN2

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Action of o-phenylenediamines upon dihydroxytartaric acid was written by Chattaway, Frederick D.;Humphrey, William G.. And the article was included in J Chem. Soc. in 1929.Formula: C8H5ClN2 This article mentions the following:

When Na dihydroxytartrate is heated with aqueous o-C₆H₄(NH₂)₂, 2 mols of the diamine react with 1 mol. only of the salt, forming quinoxaline-2,3-dicarboxy-o-phenylenediamide (I); Na dihydroxytartrate is only very sparingly soluble in H₂O and any excess above 1 mol. remains in suspension unchanged. When the filtered alk, solution is partly neutralized with HCl, I seps. as a colorless crystalline powder, stable in neutral solution and dissolving readily in cold dilute aqueous alkali, from which it is reprecipitated on addition of a deficiency of acid. It dissolves in hot dilute HCl (1:50), but on cooling, the o-phenylenediamine salt, (II) of quinxaline-2,3-dicarboxylic acid (III) seps; whereas, if it is dissolved in hot moderatelv concentrated HCl (1:1), III separated on cooling o-phenylenediamine-HCl remaining in solution The II and III may consequently be obtained directly from the original yellow condensation solution, the former by making the solution weakly acid with HCl, and the latter by saturating it with gaseous HCl. Attempts to acetylatc or benzoylate I by the usual methods also cause decomposes, with formation of the di-Ac or the di-Bz derivative of o-C₆H₄(NH₂)₂. Heated with Ac₂O, III yields the anhydide, while dry NH₃ on this anhydride in C₆H₄ suspensions gives the NH₄ salt of 3-carbamylquinoxaline-2-carboxylic acid (IV), from which the acid itself may be obtained on acidification. This amic acid is converted into the corresponding imide (V) on being heated above its m. P., and into the Ac derivative of the imide on boiling with Ac₂O. On being heated above its m. p., III decomposes, evolving CO₂ and yielding a small quantity (10%) of quinoxaline; better yields (30%) of this base are obtained by heating the NH₄ salt of the acid. In common with other N bases, quinoxaline forms a stable, well-crystallized monotetrachloroiodiede. Similarly, Na chloroquinoxaline-2,3-dicarboxy-p-chloro-o-phenylenediamide, from which the p-chloro-o-phenylenediamine salt of 6-chloroquinoxaline-2,3-dicarboxylic acid, and the free acid (VI) are obtained by heating with dilute and with concentrated HCl, resp. p-Bromo-o-phenylenediamine gives the corresponding Br derivative These halogen-substituted derivatives are considerably less soluble than the unsubstituted compounds, and are therefore more readily prepared and purified; otherwise their reactions are analogous. The following compounds were prepared and characterized: I, m. 184° (decomposition). II, lemon-yellow, m. 186° (decomposition). III, prisms containing 2 mols. H₂O of crystallization, m. 190° (decomposition after loss of H₂O at 110°); Et ester, C₁₄H₁₄O₄N₂, prisms, m. 83°; NH₄ salt, m. 220-30°; anhydride, pale yellow prisms decomposing and charring 250-60°. IV, m. 190-5° (decomposition). V, pale yellow, m. about 260° (decompose); Ac derivative, leaflets, m. about 220° (decomposition). Quinoxaline mono-tetrachloroiodide, C₆H₄N₂. HICl₄, m. 125-30° (decomposition). 6-Chlroquinoxaline-2,3-dicarboxy-p-chloro-o-phenylenediamide, C₁₆H₈O₂N₄Cl₂, m. 207° (decomposition) (p-chloro-o-phenylenediamine salt, C₁₆H₁₈O₄N₄Cl₃, m. 205° (decomposition)); 6-bromoquinoxaline-2,3-dicarboxy-p-bromo-o-phenylenediamide, m. 198° (decomposition) (p-bromo-o-phenyleneamine salt, m. 199° (decomposition)). VI, m. 175° (decomposition) (anhydride,m. 235-40° (decomposition), Et H ester, m. 159°; di-Et ester, m. 60°; NH₄ salt, m. 215-25° (decomposition)). 6-Chloroquinoxaline, m. 60°, 6-Bromoquinoxaline-2,3-dicarboxylic acid, m. 172° (decomposition) (anhydride, m. 235-45° (decomposition), Et H ester, m. 161°, di-Et ester, m. 69°, NH₄ salt, m. 235-40° (decomposition)). 6-Bromoquinoxaline, m. 56°. Pyrazinetetracarboxylic acid (by oxidation of the anhydride of III), m. 205° (decomposition), di-K di-H salt is crystalline, tetra-Et ester, m. 104°. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1Formula: C8H5ClN2).

6-Chloroquinoxaline (cas: 5448-43-1) belongs to quinoxaline derivatives. Quinoxalines are important class of heterocyclic compounds, associated with wider pharmacological applications. The antitumoral properties of quinoxaline compounds have been of interest. Recently, quinoxaline and its analogs have been investigated as the catalyst’s ligands.Formula: C8H5ClN2

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Versatile (Pentamethylcyclopentadienyl)rhodium-2,2′-Bipyridine (Cp*Rh-bpy) Catalyst for Transfer Hydrogenation of N-Heterocycles in Water was written by Zhang, Lingjuan;Qiu, Ruiying;Xue, Xiao;Pan, Yixiao;Xu, Conghui;Li, Huanrong;Xu, Lijin. And the article was included in Advanced Synthesis & Catalysis in 2015.Reference of 5448-43-1 This article mentions the following:

A study employing the catalytic system consisting of (pentamethylcyclopentadienyl)rhodium dichloride dimer [Cp*RhCl₂]₂ and 2,2′-bipyridine (bpy) for transfer hydrogenation of a variety of quinoxalines, quinoxalinones, quinolines and indoles under aqueous conditions with formate as the hydrogen source is reported. This approach provides various tetrahydroquinoxalines, dihydroquinoxalinones, tetrahydroquinolines and indolines in good to excellent yields. The activity of the catalyst towards quinoxalines and quinoxalinones is excellent, with a substrate to catalyst ratio (S/C) of 10000 being feasible. The choice of ligand is critical to the catalysis, and the aqueous phase reduction is highly pH-dependent, with acidic pH values needed for optimal reduction The catalyst is easy to access, and the reaction is operationally simple without requiring an inert atm. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1Reference of 5448-43-1).

6-Chloroquinoxaline (cas: 5448-43-1) belongs to quinoxaline derivatives. Condensed heterocycles of quinoxalines have become attractive targets in synthetic and medicinal chemistry due to their significant biological activities. The parent substance of the group, quinoxaline, results when glyoxal is condensed with 1,2-diaminobenzene. Substituted derivatives arise when α-ketonic acids, α-chlorketones, α-aldehyde alcohols and α-ketone alcohols are used in place of diketones.Reference of 5448-43-1

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

PAd2-DalPhos Enables the Nickel-Catalyzed C-N Cross-Coupling of Primary Heteroarylamines and (Hetero)aryl Chlorides was written by Clark, Jillian S. K.;Ferguson, Michael J.;McDonald, Robert;Stradiotto, Mark. And the article was included in Angewandte Chemie, International Edition in 2019.Computed Properties of C8H5ClN2 This article mentions the following:

Base-metal catalysts capable of enabling the assembly of heteroatom-dense mols. by cross-coupling of primary heteroarylamines and (hetero)aryl chlorides, while sought-after given the ubiquity of unsym. di(hetero)arylamino fragments in pharmacophores, are unknown. Herein, we disclose the new “double cage” bisphosphine PAd2-DalPhos (L2). The derived air-stable Ni^II pre-catalyst C2 functions well at low loadings in challenging test C-N cross-couplings with established substrates, and facilitates the first Ni-catalyzed C-N cross-couplings of primary five- or six-membered ring heteroarylamines and activated (hetero)aryl chlorides, with synthetically useful scope that is competitive with Pd catalysis. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1Computed Properties of C8H5ClN2).

6-Chloroquinoxaline (cas: 5448-43-1) belongs to quinoxaline derivatives. Condensed heterocycles of quinoxalines have become attractive targets in synthetic and medicinal chemistry due to their significant biological activities. Quinoxaline and its analogues may also be formed by reduction of amino acids substituted 1,5-difluoro-2,4-dinitrobenzene (DFDNB),One study used 2-iodoxybenzoic acid (IBX) as a catalyst in the reaction of benzil with 1,2-diaminobenzene.Computed Properties of C8H5ClN2

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Reduction of heterocyclic compounds. I. Reduction of heterocyclic compounds with diborane was written by Nose, Atsuko;Kudo, Tadahiro. And the article was included in Yakugaku Zasshi in 1979.Formula: C9H8N2O This article mentions the following:

Reaction of quinoline and isoquinoline with B₂H₆, followed by treatment with HCl, afforded the corresponding 1,2,3,4-tetrahydro compounds However, quinaldine gave traces of 1,2,3,4-tetrahydroquinaldine, and neither lepidine nor 3-methylisoquinoline were reduced under similar conditions. Quinoxaline derivatives reacted with B₂H₆ alone to give the corresponding 1,2,3,4-tetrahydro derivatives in quant. yields. In the experiment, the researchers used many compounds, for example, 6-Methoxyquinoxaline (cas: 6639-82-3Formula: C9H8N2O).

6-Methoxyquinoxaline (cas: 6639-82-3) belongs to quinoxaline derivatives. Quinoxaline is isomeric with other naphthyridines including quinazoline, phthalazine and cinnoline. They are well-known for application in organic light emitting devices, polymers and pharmaceutical agents. The quinoxaline-containing polymers are applicable in optical devices due to their thermal stability and low band gap.Formula: C9H8N2O

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

A near-infrared fluorescent probe with an improved Stokes shift achieved by tuning the donor-acceptor-donor character of the rhodamine skeleton and its applications was written by Gong, Jin;Liu, Chang;Jiao, Xiaojie;He, Song;Zhao, Liancheng;Zeng, Xianshun. And the article was included in RSC Advances in 2020.COA of Formula: C9H8N2O This article mentions the following:

In this paper, we report a novel near-IR (NIR) mitochondrion-targeted fluorescent probe, RQS, with an improved Stokes shift (96 nm) for the specific detection of mitochondrial mercury ion (Hg2+) because mitochondrion is one of the main targeted organelles of Hg²⁺. For the preparation of the probe, a novel asym. fluorescent xanthene dye RQ was first synthesized by tuning the donor-acceptor-donor (D-A-D) character of the rhodamine skeleton, and then the probe RQS was constructed by the mechanism of mercury-promoted ring-opening reaction. As expected, RQS could be used for the specific detection of Hg²⁺ with high selectivity, high sensitivity, and a detection limit down to the nanomolar range (2 nM). Importantly, RQS is capable of specifically distributing in mitochondria, and thus detect Hg²⁺ in real-time and provided a potential tool for studying the cytotoxic mechanisms of Hg²⁺. In the experiment, the researchers used many compounds, for example, 6-Methoxyquinoxaline (cas: 6639-82-3COA of Formula: C9H8N2O).

6-Methoxyquinoxaline (cas: 6639-82-3) belongs to quinoxaline derivatives. Condensed heterocycles of quinoxalines have become attractive targets in synthetic and medicinal chemistry due to their significant biological activities. The antitumoral properties of quinoxaline compounds have been of interest. Recently, quinoxaline and its analogs have been investigated as the catalyst’s ligands.COA of Formula: C9H8N2O

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Substituent effect on local aromaticity in mono and di-substituted heterocyclic analogs of naphthalene was written by Mohajeri, Afshan;Shahamirian, Mozhgan. And the article was included in Journal of Physical Organic Chemistry in 2010.Electric Literature of C9H8N2O This article mentions the following:

A quant. study on local aromaticity has been performed on a series of mono- and di-substituted biheterocycles (quinoline, isoquinoline, quinoxaline, quinazoline). Three electronically based indexes (PDI, ATI, and FLU) have been employed to investigate the substituent effect on the π-electron delocalization in both heterocycle and benzenoid rings. Three typical substituents (Cl, OCH₃, and CN) with different inductive and resonance power have been selected. Generally, substituent causes a reduction in aromaticity irresp. of whether it is electron attracting or electron donating. It is shown that the maximum aromaticity exhibits a similar trend of Cl > CN > OCH₃ for all the studied rings. Moreover, it is found that the substituent situation with respect to the heteroatom has a significant influence on the aromaticity. It results from our study that in di-substituted derivatives, irresp. of whether the two substituents form a meta or para isomer, they preferably choose the position which leads to the maximum aromaticity character. Copyright © 2009 John Wiley & Sons, Ltd. In the experiment, the researchers used many compounds, for example, 6-Methoxyquinoxaline (cas: 6639-82-3Electric Literature of C9H8N2O).

6-Methoxyquinoxaline (cas: 6639-82-3) belongs to quinoxaline derivatives. Quinoxaline is isomeric with other naphthyridines including quinazoline, phthalazine and cinnoline. Modifying quinoxaline structure it is possible to obtain a wide variety of biomedical applications, namely antimicrobial activities and chronic and metabolic diseases treatment.Electric Literature of C9H8N2O

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

A facile, catalyst-free mechano-synthesis of quinoxalines and their in-vitro antibacterial activity study was written by Bhutia, Zigmee T.;Prasannakumar, Geethika;Das, Avijit;Biswas, Malabika;Chatterjee, Amrita;Banerjee, Mainak. And the article was included in ChemistrySelect in 2017.Reference of 5448-43-1 This article mentions the following:

A catalyst-free, greener and highly efficient method for the synthesis of quinoxaline derivatives I (R¹ = Ph, Me, H, etc.; R² = H, Me; R³ = H, Me, Cl, NO₂; R⁴ = H, Me; X = CH, N) involving simple liquid assisted hand-grinding (LAG) in a mortar and pestle was developed. The mechanochem. agitation under LAG was sufficient enough for the smooth condensation of both aromatic and heteroaromatic 1,2-diamines with a variety of 1,2-dicarbonyl compounds to afford the corresponding quinoxalines in high yields. Several of these quinoxaline derivatives inhibited the growth of Mycobacterium smegmatis in moderate to good effect. Simple substitution in the quinoxaline ring was found to be more effective in antibacterial agents than bulky substitution. In particular, pyrido[2,3-b]pyrazines I (R¹ = H, CH₃; R² = R⁴ = H; R³ = H, Br; X = N) showed better activity than others. Overall, the key advantages of this method were simplicity of operation, catalyst-free condition, solvent-less synthesis, low E-factor, cleaner reaction profile, devoid of work-up step, easy purification and shorter reaction times, and the new series of pyrido[2,3-b]pyrazines were good antibacterial agents against M. smegmatis. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1Reference of 5448-43-1).

6-Chloroquinoxaline (cas: 5448-43-1) belongs to quinoxaline derivatives. Quinoxalines are important class of heterocyclic compounds, associated with wider pharmacological applications. Quinoxalines are used in the treatment of bacterial, cancer, and HIV infections. Moreover, varenicline, a clinical drug is used for treating nicotine addiction, also contains quinoxaline moiety.Reference of 5448-43-1

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Organic Base Enabled Nickel-Catalyzed Mono-α-Arylation of Feedstock Solvents was written by MacMillan, Joshua W. M.;McGuire, Ryan T.;Stradiotto, Mark. And the article was included in Chemistry – A European Journal in 2022.Application of 5448-43-1 This article mentions the following:

Authors report on authors’ successful development of the first metal-catalyzed mono-α-arylation of carbonyl compounds employing a soluble organic base. The scope of these Ni/DalPhos-catalyzed transformations encompasses a range of (hetero)aryl halides (Cl, Br, I) and phenol-derived electrophiles (sulfonates, carbonates, carbamates, sulfamates), including active pharmaceutical ingredients (chloroquine, clozapine), in combination with the typically problematic feedstock small mol. substrates acetone, dimethylacetamide, and for the first time with any metal catalyst/base, Et acetate. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1Application of 5448-43-1).

6-Chloroquinoxaline (cas: 5448-43-1) belongs to quinoxaline derivatives. Quinoxalines have received a significant amount of attention due to their potential use in fighting various pathophysiological conditions like epilepsy, Parkinson’s, and Alzheimer’s diseases. Modifying quinoxaline structure it is possible to obtain a wide variety of biomedical applications, namely antimicrobial activities and chronic and metabolic diseases treatment.Application of 5448-43-1

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Proton magnetic resonance spectra in aromatic systems. XIII. Heteroaromatic series. 5. 6-Substituted quinoxalines was written by Sasaki, Yoshio;Hatanaka, Minoru;Suzuki, Miyoko. And the article was included in Yakugaku Zasshi in 1969.Category: quinoxaline This article mentions the following:

The chem. shifts of the ring 1H of 6-quinoxalines have been corrected for N anisotropy, N elec. field, and ring current effects. The corrected shifts have also been correlated with the substituent constants σπ, and those corresponding to the π-electron charge density-ρ-distributions were estimated, and converted to ρ values. In the experiment, the researchers used many compounds, for example, 6-Methoxyquinoxaline (cas: 6639-82-3Category: quinoxaline).

6-Methoxyquinoxaline (cas: 6639-82-3) belongs to quinoxaline derivatives. Compounds possessing quinoxaline derivatives were bestowed with a variety of significant biological properties such as antiviral, antimalarial, anticancer, DNA intercalation, DNA duplex stabilization, and many others. Quinoxalines are used as dyes, pharmaceuticals, and antibiotics such as echinomycin, levomycin exhibiting antitumoral properties. Quinoxalines establish also the basis of anthelmintics and receptor antagonists.Category: quinoxaline

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider