Day: January 5, 2023

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

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

An efficient synthesis and biological activity of quinoxaline-2-carboxylic acid and its derivatives was written by Kumar, Navneet;Sharma, Pratima;Kaur, Navjeet;Pareek, Aastha. And the article was included in Journal of Applicable Chemistry (Lumami, India) in 2013.Reference of 49679-45-0 This article mentions the following:

Condensation of ortho phenyldiamine with acetic acid and form 2-tetrahydroxy Bu quinoxaline which further react with hydrogen peroxide and solid sodium hydroxide form quinoxaline-2-carboxylic acid. Ethyl-3-hydroxyquinoxaline-2-carboxylate reacts with POCl₃ and to form ethyl-3-chloroquinoxaline-2-carboxylate. Ethyl-3-chloroquinoxaline-2-carboxylate reacts with sodium hydroxide, alc., sodium methoxide and form 3-ethoxyquinoxaline-2-carboxylic acid, 3-amino quinoxaline-2-carboxylic acid, 3-methoxy quinoxaline-2-carboxylic acid, with good yield. The structure of the compounds was established on the basis of IR, and ¹H NMR, spectral data. In the experiment, the researchers used many compounds, for example, Ethyl 3-chloroquinoxaline-2-carboxylate (cas: 49679-45-0Reference of 49679-45-0).

Ethyl 3-chloroquinoxaline-2-carboxylate (cas: 49679-45-0) belongs to quinoxaline derivatives. Quinoxaline is isomeric with other naphthyridines including quinazoline, phthalazine and cinnoline. Quinoxaline-1,4-di-N-oxide derivatives have shown to improve the biological results and are endowed with anti-viral, anti-cancer, anti-bacterial, and anti-protozoal activities with application in many other therapeutic areas.Reference of 49679-45-0

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

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

Anti-depressant-like activity of a novel serotonin type-3 (5-HT₃) receptor antagonist in rodent models of depression was written by Gupta, Deepali;Devadoss, Thangaraj;Bhatt, Shvetank;Gautam, Baldev;Jindal, Ankur;Pandey, Dilip;Mahesh, Radhakrishnan. And the article was included in Indian Journal of Experimental Biology in 2011.Application of 49679-45-0 This article mentions the following:

N-Cyclohexyl-3-methoxyquinoxalin-2-carboxamide (QCM-13), a novel 5-HT₃ antagonist identified from a series of compounds with higher pA₂ (7.6) and good log P (2.91) value was screened in rodent models of depression such as forced swim test (FST), tail suspension test (TST), interaction studies with standard anti-depressants and confirmatory studies such as reversal of parthenolide induced depression and reserpine induced hypothermia. In FST (2 and 4 mg/kg) and TST (2 and 4 mg/kg), QCM-13 significantly reduced the duration of immobility in mice without affecting the base line locomotion. QCM-13 (2 and 4 mg/kg) was also found to have significant interaction with standard anti-depressants (fluoxetine and bupropion in FST and TST resp.). Further, reversal of parthenolide induced depression in mice and reserpine induced hypothermia in rat models indicate the serotonergic influence of QCM-13 for anti-depressant potential. In the experiment, the researchers used many compounds, for example, Ethyl 3-chloroquinoxaline-2-carboxylate (cas: 49679-45-0Application of 49679-45-0).

Ethyl 3-chloroquinoxaline-2-carboxylate (cas: 49679-45-0) belongs to quinoxaline derivatives. Quinoxaline derivatives are important constituents of pharmacologically active compounds, including as well as for RNA synthesis inhibition, reactive dyes and pigments, azo dyes, flurox Cylin Dyes, Corrosion Inhibitors and Photovoltaic Polymers. 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.Application of 49679-45-0

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Homogeneous Nickel-Catalyzed Sustainable Synthesis of Quinoline and Quinoxaline under Aerobic Conditions was written by Bains, Amreen K.;Singh, Vikramjeet;Adhikari, Debashis. And the article was included in Journal of Organic Chemistry in 2020.Name: 6-Methoxyquinoxaline This article mentions the following:

Dehydrogenative coupling-based reactions have emerged as an efficient route toward the synthesis of a plethora of heterocyclic rings. Herein, we report an efficacious, nickel-catalyzed synthesis of two important heterocycles such as quinoline and quinoxaline. The catalyst is molecularly defined, is phosphine-free, and can operate at a mild reaction temperature of 80°C. Both the heterocycles can be easily assembled via double dehydrogenative coupling, starting from 2-aminobenzyl alc./1-phenylethanol and diamine/diol, resp., in a shorter span of reaction time. This environmentally benign synthetic protocol employing an inexpensive catalyst can rival many other transition-metal systems that have been developed for the fabrication of two putative heterocycles. Mechanistically, the dehydrogenation of secondary alc. follows clean pseudo-first-order kinetics and exhibits a sizable kinetic isotope effect. Intriguingly, this catalyst provides an example of storing the trapped hydrogen in the ligand backbone, avoiding metal-hydride formation. Easy regeneration of the oxidized form of the catalyst under aerobic/O₂ oxidation makes this protocol eco-friendly and easy to handle. In the experiment, the researchers used many compounds, for example, 6-Methoxyquinoxaline (cas: 6639-82-3Name: 6-Methoxyquinoxaline).

6-Methoxyquinoxaline (cas: 6639-82-3) belongs to quinoxaline derivatives. Quinoxaline derivatives are important constituents of pharmacologically active compounds, including as well as for RNA synthesis inhibition, reactive dyes and pigments, azo dyes, flurox Cylin Dyes, Corrosion Inhibitors and Photovoltaic Polymers. 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.Name: 6-Methoxyquinoxaline

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Electronic transitions in the aromatic chlorazines. III. Absorption spectra of monochloro quinoxalines, phthalazines, quinazolines, and cinnolines was written by Favini, Giorgio;Simonetta, Massimo. And the article was included in Gazzetta Chimica Italiana in 1960.Synthetic Route of C8H5ClN2 This article mentions the following:

The absorption spectra of 2-, 5-, and 6-chloroquinoxalines (I, II, III), 2-, 4-, and 6-chloroquinazolines (IV, V, VI), 1-, 5-, and 6-chlorophthalazines (VII, VIII, IX), and 3-, and 4-cinnolines (X, XI) were measured in isoöctane and in MeOH between 220 and 450 mμ. Condensation of o-(H₂N)₂C₆H₄ and OC(CO₂Et)₂ and hydrolysis, decarboxylation of the 2-hydroxyquinoxaline-3-carboxylic acid and chlorination with POCl₃ gave I, m. 46-7° (C₅H₁₂). Acetylation of o-ClC₆H₄NH₂ and nitration with fuming HNO₃, deacetylation of the crystalline 2,6-Cl-(O₂N)C₆H₃NHAc with NaOH, reduction with SnCl₂, and condensation of the reduction product with OHCCHO.(NaHSO₃)₂ yielded II, m. 61-2° (petr. ether). Similarly, com. 4,2-Cl(H₂N)C₆H₃NH₂ was transformed to III, m. 63-4° (petr. ether). Reduction of o-O₂NC₆H₄CHO, condensation with urea, and chlorination of the 2-quinazolone with PCl₃ and POCl₃ gave IV, m. 108° (ligroine). HCONH₂ condensed with o-H₂NC₆H₄CO₂H and the 4-quinazolone chlorinated with PCl₅ and POCl₃ successively yielded V, m. 99-100° (petr. ether). Nitration of 3-ClC₆H₄CHO and condensation with HCONH₂ followed by reduction with Zn in AcOH gave VI, m. 145° (dilute alc.). Phthalide transformed through the Br derivative into o-OHCC₆H₄CO₂H, condensed with N₂H₄.H₂O to the phthalazone and chlorinated with POCl₃ yielded VII, m. 110-11° (ligroine). Conversion of 3,4-Me₂C₆H₃NH₂ by the Sandmeyer reaction gave 10 g. 3,4-Me₂C₆H₃Cl, converted through 3,4-(CHBr₂)₂C₆H₃Cl to 3,4-(OHC)₂C₆H₃Cl and condensed with N₂H₄ to yield 0.4 g. IX, m. 132°. α-Tetrahydronaphthylamine (5 g.) converted according to Sandmeyer to α-chlorotetrahydronaphthalene and submitted to oxidative degradation, the isomeric mixture condensed with N₂H₄, the product chlorinated with POCl₃ and the mixture of dichlorophthalazines (0.2 g.) treated with HI and P to eliminate the Cl of the heterocyclic ring gave a small amount of VIII. HCN added to o-O₂NC₆H₄CHO and the nitrile saponified, the NO₂ group reduced catalytically and the acid diazotized, reduced with SnCl₂ and the 3-hydroxycinnoline chlorinated with POCl₃ gave X, m. 90-1° (ligroine). MeCOPh nitrated and reduced with Sn and HCl, the o-H₂NC₆H₄COMe diazotized and transformed into 4-hydroxycinnoline, treated successively with PCl₅ and POCl₃, and recrystallized from ligroine gave XI, m. 78-9°. The nature of the bands observed and the infuence exerted on the absorption maximum by introduction of an atom of Cl into the benzodiazine structure were discussed. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1Synthetic Route 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. 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.Synthetic Route of C8H5ClN2

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Electronic transitions in the aromatic chlorazines. II. Application of the method of Pariser and Parr to the azines of the monochlorinated benzene series was written by Favini, Giorgio;Simonetta, Massimo. And the article was included in Gazzetta Chimica Italiana in 1960.COA of Formula: C8H5ClN2 This article mentions the following:

The semiempirical method of Pariser and Parr was applied to PhCl (I), 2-, 3-, and 4-chloropyridines (II, III, IV), 2-, 3-, and 4-chloropyrimidines (V, VI, VII), chloropyrazine (VIII), and 3-chloropyridazine (IX). Comparison between theoretical and exptl. findings was limited to the values of energy transitions and oscillator strengths for the 1st singlet-singlet π-π’ transition. Monocentric and bicentric Coulomb integrals were calculated and tabulated. E was calculated for β_CCl -0.86 and -2.50 without configuration interaction and with interaction of 5 and 8 configurations and the tabulated values were compared with exptl. values of ΔE. Oscillator strengths were calculated and similarly compared. The theory confirmed in all instances the bathochromic effect on the absorption maximum of the π-π’ transition caused by the introduction of an atom of Cl into C₆H₆ or an azine and, moreover gave shifts of the correct order of magnitude as shown by the tabulation (compound, Δν theoretical and exptl. (cm.^-1) given): I, -870, -1350; II, -860, -1850; III, -1370, -2300; IV, -1830, -990; V, -1090, -1900; VI, -1730, -1250; VII, -2800, -2820; VIII, -970, -1460; IX, -2410, -1860. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1COA of Formula: 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.COA of Formula: C8H5ClN2

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Cross-Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate-Determining Deprotonation of Bound Hydrazine was written by Wang, Justin Y.;Choi, Kyoungmin;Zuend, Stephan J.;Borate, Kailaskumar;Shinde, Harish;Goetz, Roland;Hartwig, John F.. And the article was included in Angewandte Chemie, International Edition in 2021.HPLC of Formula: 5448-43-1 This article mentions the following:

Reported here is the Pd-catalyzed C-N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate-limiting deprotonation of a hydrazine-bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex. Hydrazine is highly toxic and should be handled with proper personal protection equipment. Hydrazine can also explode in the presence of elevated temperatures and oxygen, and this reaction is catalyzed by transition metals. In the experiment, the researchers used many compounds, for example, 6-Chloroquinoxaline (cas: 5448-43-1HPLC of Formula: 5448-43-1).

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. Modifying quinoxaline structure it is possible to obtain a wide variety of biomedical applications, namely antimicrobial activities and chronic and metabolic diseases treatment.HPLC of Formula: 5448-43-1

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider