Tag: 100-200

Pyridopyrazines was written by Zhang, J.. And the article was included in Science of Synthesis, Knowledge Updates in 2010.Synthetic Route of C7H5N3 This article mentions the following:

This manuscript is an update of the original Science of Synthesis chapter and includes methods for the preparation of pyrido[2,3-b]pyrazine derivatives and pyrido[3,4-b]pyrazine derivatives described in the literature up to 2010. Methods proceeding by a condensation of pyridinediamine derivatives with carbonyl compounds and the application of (halo)pyrido[2,3-b]pyrazines by palladium-catalyzed cross-coupling reactions are covered. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Synthetic Route of C7H5N3).

Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine is an N-heterocyclic moiety, and it can be easily prepared from ethylenediamine and 1,2-diketone, α-hydroxyketone, α-methyl ketone. Pyrazine heterocycles and their benzo derivatives possess many interesting properties, including chemical reactivity profiles, and have diverse applications in total synthesis, medicine, chemical biology, materials, dyes, and imaging.Synthetic Route of C7H5N3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Structure-activity study of diuretic azanaphthalene derivatives was written by Mizuta, Eiji;Nishikawa, Kohei;Omura, Kiyoshi;Oka, Yoshikazu. And the article was included in Chemical & Pharmaceutical Bulletin in 1976.HPLC of Formula: 322-46-3 This article mentions the following:

Regression anal. by the Free-Wilson technique was applied to estimate the contribution of substituents on azanaphthalene skeletons to diuretic activity of pyrimido[4,5-d]pyridazine and pyrido[3,4-d]pyridazine derivatives In the former group, one of the most preferable compounds was DS-210 [2-phenyl-5,8-dimorpholinopyrimido[4,5-d]pyridazine](I) [33222-18-3] and that in the latter group proved to be DS-511 (1,4-dimorpholine-7-phenylpyrido[3,4-d]pyridazine)(II) [39632-88-7]. Subsequently, electron d. distributions on a variety of azanaphthalene skeletons were calculated by extended Huckel Theory calculation Linear multiple regression anal. to find a correlation between diuretic activity and electron d. at some positions of azanaphthalene skeletons suggested that the diuretic activity might be influenced largely by electronic structures at the ring junction. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3HPLC of Formula: 322-46-3).

Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine is an N-heterocyclic moiety, and it can be easily prepared from ethylenediamine and 1,2-diketone, α-hydroxyketone, α-methyl ketone. A large number of pyrazine derivatives are known for their antitumor, antibiotic, anticonvulsant, antituberculosis, and diuretic activities.HPLC of Formula: 322-46-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Pyrazinium Salts as Efficient Organocatalysts of Mild Oxidations with Hydrogen Peroxide was written by Menova, Petra;Kafka, Frantisek;Dvorakova, Hana;Gunnoo, Smita;Sanda, Miloslav;Cibulka, Radek. And the article was included in Advanced Synthesis & Catalysis in 2011.Category: pyrazines This article mentions the following:

A series of 3-substituted pyrazinium tetrafluoroborates was prepared as simple analogs of flavinium salts which are efficient organocatalysts for oxidations with hydrogen peroxide. It was shown that pyrazinium derivatives with an electron-withdrawing substituent catalyze mild oxidations of sulfides to sulfoxides and Baeyer-Villiger oxidations in a similar way to flavinium catalysts. The most reactive catalyst, 3-cyanopyrazinium tetrafluoroborate, was efficiently employed in preparative sulfoxidations of aromatic and aliphatic sulfides as well as in Baeyer-Villiger oxidations of cyclobutanones. A proposed mechanism for the catalysis is based on the formation of pyrazine hydroperoxide which is the agent oxidizing the substrate. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Category: pyrazines).

Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) belongs to pyrazine derivatives. Pyrazinesare six-membered aromatic heterocyclic organic compounds with two nitrogen atoms at 1,4-positions. Pyrazine is a weaker base (pKb = 13.4) than pyridine (pKb = 8.8), pyrimidine (pKb = 12.7). Pyrazines undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.Category: pyrazines

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Anionic CO₂ activation in the anionic and di-anionic state of aza-naphthalene was written by Park, Chang Jun;Heo, One;Lee, Hyeon Seok;Lee, Kyung Suh;Lee, Sang Hak. And the article was included in RSC Advances in 2021.Formula: C7H5N3 This article mentions the following:

Nitrogen-containing polycyclic aromatic hydrocarbon (PAH) is the single basic moiety in N-doped graphene, the only metal-free catalyst reported to date to successfully produce the oxygen reduction reaction. N-doped graphene is quite promising as a material to increase the efficiency of oxygen reduction In addition, it is known that when carbon dioxide is added to aza-benzene, there will be an associative chem. reaction upon electron attachment between the anionic nitrogen atoms in the aza-benzene and the carbon atom in the carbon dioxide; however, it has previously been reported that when there are more nitrogen atoms in the small aza-benzene moiety, the associative reaction does not always occur. In this study, we carried out a theor. simulation to determine whether more electrons increase the CO₂ reductive reactivity of the aza-naphthalene as a model system of a nitrogen-containing polycyclic aromatic hydrocarbon. We found that even though an associative chem. reaction between nitrogen atoms in the N-PAH and carbon atoms in carbon dioxide did not occur in anionic complexes of aza-naphthalene and carbon dioxide, chem. reactions did occur in all the nitrogen atoms of these complexes when we added an extra excess electron. Therefore, we conclude that the efficiency of CO₂ reduction will be increased in nitrogen atoms when more electrons are added to increase their anionic properties. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Formula: C7H5N3).

Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine is a symmetrical molecule with point group D2h. Pyrazine is less basic than pyridine, pyridazine and pyrimidine. Pyrazine and a variety of alkylpyrazines are flavor and aroma compounds found in baked and roasted goods. Tetramethylpyrazine (also known as ligustrazine) is reported to scavenge superoxide anion and decrease nitric oxide production in human Granulocytes.Formula: C7H5N3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Design, synthesis and anti-inflammatory evaluation of novel 5-benzylidene-3,4-dihalo-furan-2-one derivatives was written by Wang, Fang;Sun, Jun-Rong;Huang, Mei-Yan;Wang, Hui-Ying;Sun, Ping-Hua;Lin, Jing;Chen, Wei-Min. And the article was included in European Journal of Medicinal Chemistry in 2014.Name: (3,5,6-Trimethylpyrazin-2-yl)methanol This article mentions the following:

Rosiglitazone has shown promising anti-inflammation effect. To develop preferable anti-inflammatory agents, twenty-two rosiglitazone analogs were synthesized and their anti-inflammatory activity was evaluated. Among these compounds, I and II displayed excellent inhibitory activities on the production of inflammatory mediators, including nitric oxide (NO), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Furthermore, I and II showed suppression effects on the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, and this suppression effects could be partially reversed by GW9662, which is a peroxisome proliferator-activated receptor γ (PPARγ) antagonist. Addnl., our docking results exhibited the well combination of I and II to PPARγ. So the anti-inflammation activity of I and II was due at least in part, to their interaction with PPARγ. In the experiment, the researchers used many compounds, for example, (3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3Name: (3,5,6-Trimethylpyrazin-2-yl)methanol).

(3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3) belongs to pyrazine derivatives. Pyrazine derivatives have antitumor, antibiotic, anticonvulsant, antituberculous and diuretic effects as well as kinase, enzymatic and potent tubulin and FtsZ polymerization inhibitory activities. A large number of pyrazine derivatives are known for their antitumor, antibiotic, anticonvulsant, antituberculosis, and diuretic activities.Name: (3,5,6-Trimethylpyrazin-2-yl)methanol

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Hydrophobicity parameter of diazines. 1. Analysis and prediction of partition coefficients of monosubstituted diazines was written by Yamagami, Chisako;Takao, Narao;Fujita, Toshio. And the article was included in Quantitative Structure-Activity Relationships in 1990.Related Products of 6924-68-1 This article mentions the following:

The octanol/water partition coefficient (P) of a number of monosubstituted diazines was measured. The composition of the π value of substituents, the increment in the log P value accompanying the introduction of substituents, was examined in terms of physicochem. substituent parameters and correlation anal. The diazine-π value of substituents was generally higher than the pyridine-π value of corresponding substituents, indicating that the intramol. electronic interactions between the ring-N atoms and substituent are more pronounced than those in substituted pyridines in governing the log P value of the mol. Except for 2-substituted pyrimidines, the π value of substituents in each series of monosubstituted diazines was in general nicely correlated with the π value of the corresponding substituents in substituted pyridines along with electronic parameter terms representing bidirectional electronic effects on the relative solvation of the ring-N atom(s) and the hydrogen-bondable substituents with partitioning solvents according to the procedure proposed previously for the anal. of the π value in disubstituted benzenes and monosubstituted pyridines. Keeping in mind that 2-pyrimidines substituted by hydrogen-bondable groups sometimes behave as outliers, the correlations were believed to be usable for prediction of log P values of monosubstituted diazines. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Related Products of 6924-68-1).

Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) belongs to pyrazine derivatives. Pyrazine derivatives have antitumor, antibiotic, anticonvulsant, antituberculous and diuretic effects as well as kinase, enzymatic and potent tubulin and FtsZ polymerization inhibitory activities. A number of pyrazine-based derivatives were used as dyes or fluorescent probes.Related Products of 6924-68-1

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Method of predicting the site of alkylation of heterocyclic polyazines from kinetic data on model compounds was written by Zoltewicz, J. A.;Deady, L. W.. And the article was included in Tetrahedron in 1972.Synthetic Route of C7H5N3 This article mentions the following:

A method is presented which enables calculation of isomer ratios resulting from the N-methylation of polyazines in Me2SO. The method assumes that substituent and annular N atom effects on reactivity are additive in the absence of steric factors. Kinetic studies on model azines provide rate factors which are employed in the calculations Observed and calculated isomer ratios are compared for a number of polyazines. An extension to N-oxidation is suggested. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Synthetic Route of C7H5N3).

Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazines are part of several biologically active polycyclic compounds; examples are quinoxalines, phenazines; and the bio-luminescent natural products pteridines, flavins, and their derivatives. Pyrazines are chemical compounds (technically called “methoxypyrazines”) found in grape skin and stems that are responsible for many “green” flavors in wine. Levels of pyrazines are dependent on viticultural practices, climate, and grape variety.Synthetic Route of C7H5N3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Azaquinoxalines was written by Bodforss, Sven. And the article was included in Justus Liebigs Annalen der Chemie in 1964.Application of 322-46-3 This article mentions the following:

A series of azaquinoxalines was prepared from 2,3-diaminopyridine (I) with α-dicarbonyl compounds Equivalent amounts of PhCH:CHCOCO₂H (II) and I in EtOH yielded the I-II salt, decompose 144° (EtOH or hot H₂O). I-II salt refluxed about 10 min. in AcOH gave about 20% 2-styryl-5(or 8)-aza-3-quinoxalone (III), 251° (AcOH). The ο-NO₂ derivative (2 g.) of II and 1 g. I refluxed 4 hrs. in AcOH and EtOH yielded the 2-(ο-O₂NC₆H₄CH:CH) analog of III, decompose 275° (HCONMe₂). BzCH₂COCO₂H and I (equimolar amounts) mixed in EtOH, and the resulting salt refluxed in AcOH gave quant. the 2-BzCH₂ analog (IV) of III, ∼283° (AcOH). IV (2 g.) in 20 g. concentrated H₂SO₄ and 2.5 g. P₂O₅ heated 2 days at 100° yielded 2-phenyl-5-azafuro[2,3b]quinoxaline (V), m. 251° (AcOH), and some SO₃H derivative (VI) of V which was isolated as the pyridinium salt; the salt in H₂O treated with dilute HCl gave VI. III (2.3 g.) in CHCl₃ treated slowly in sunlight with 1.6 g. Br in AcOH, and the resulting crude dibromide refluxed with 10 cc. dry C₅H₅N gave VII (X = Br), which was dissolved in H₂O and treated with NaClO₄ to give VII (X = ClO₄), brown-yellow microcrystals. I (2.3 g.) and 15 cc. (CO₂Et)₂ refluxed 1 hr. gave quant. 2,3-dihydroxy-5-azaquinoxaline, decompose above 300°. I (2 g.) and 4 g. Bz₂ refluxed 12 hrs. with a few drops concentrated H₂SO₄ yielded 2,3-diphenyl-5-azaquinoxaline (VIII), m. 144°. (p-HOC₆H₄CO)₂ (2 g.) and 1 g. I refluxed 2 days with 20 cc. EtOH and 2 cc. AcOH gave the bis(p-HOC₆H₄) analog of VIII, decompose 315°. I (2 g.) and 5 g. alloxan in EtOH-AcOH yielded alloxan-3(or 2)-[2(or 3)-aminopyridyl)imide, decompose ∼250° (reprecipitated from NH₄OH with AcOH). Alloxan anil refluxed 2 days with 4N KOH, adjusted to about pH 10, and acidified with dilute HCl yielded 2-carboxy-3-hydroxy-5(or 8)-azaquinoxaline, decompose ∼280°, which dissolved in hot H₂O and reprecipitated with HCl gave an unidentified, brown-red solid, decomposing above 345°. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Application of 322-46-3).

Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine is an N-heterocyclic moiety, and it can be easily prepared from ethylenediamine and 1,2-diketone, α-hydroxyketone, α-methyl ketone. A number of pyrazine-based derivatives were used as dyes or fluorescent probes.Application of 322-46-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Pyrazine chemistry. IV. Bromination of 2-amino-3-carbomethoxypyrazine was written by Ellingson, R. C.;Henry, R. L.. And the article was included in Journal of the American Chemical Society in 1949.Quality Control of 5-Aminopyrazine-2-carboxamide This article mentions the following:

The structure of the product obtained on bromination of 2-amino-3-carbomethoxypyrazine (I) was established as 2-amino-3-carbomethoxy-5-bromopyrazine (II). I (15.3 g.) in 60 cc. warm AcOH treated dropwise with 5.4 cc. Br and 450 cc. water added after 10 min. yielded 21 g. (90.5%) II, light-yellow solid, m. 175.3-5.9°. I (61.2 g.) in 330 cc. AcOH was brominated with 21.6 cc. Br, 2 l. water and 210 g. NaOH in 400 cc. water added after 30 min., and the solution boiled 15 min., treated with C, filtered, and cooled, yielding 90.5 g. Na 3-amino-6-bromopyrazinoate (C.A. numbering) which, when dissolved in 2400 cc. warm water, acidified with 60 cc. 40% HBr, and cooled, yielded 64 g. light-brown crystals of 3-amino-6-bromopyrazinoic acid (III), m. 185-6° (decomposition) (from water). A suspension of 59.6 g. crude III in 600 cc. dry tetrahydronaphthalene was refluxed 30 min., treated (hot) with C, the filtrate was chilled, and the crystals which separated were washed in petr. ether, yielding 38.4 g. 2-amino-5-bromopyrazine (IV), m. 113.6° (corrected). IV (4.0 g.), 2 g. CuCN, 3.0 g. KCN, 14.0 cc. water, and 6.0 cc. EtOH sealed in a Carius tube were heated at 170° for 16 h., then rinsed out with 400 cc. water, the suspension acidified with HCl, boiled to remove the HCN, and the Cu removed with H₂S; the cooled filtrate deposited 1.55 g. of a mixture of the amide and 6-aminopyrazinoic acid (V). The mixture was suspended in 50 cc. of 2% NaOH; the insoluble fraction (0.7 g.), 2-amino-5-carbamylpyrazine, m. 277-9° (from water). The alk. filtrate acidified with HCl gave 0.55 g. V, m. 278° (from water). Br (15.2 cc.) was added dropwise (temperature kept below 0°) to 15.3 g. I in 57 cc. 48% HBr, then 17.4 g. NaNO₂ in 30 cc. water (temperature below 0°), and finally 38 g. NaOH in 100 cc. water; next day 5.6 g. light-brown solid was collected and an addnl. 3.8 g. was obtained by extraction with EtOAc. Crystallization from 100 cc. water and 32 cc. EtOH gave 7.4 g. 2-bromo-3-carbomethoxypyrazine (VI), m. 44° (corrected). VI (3 g.), 2.5 g. CuCN, 1 g. KCN, 7 cc. EtOH, and 12 cc. water sealed in a Carius tube were heated 16 h. at 125°, the filtered suspension made alk., boiled 1 h., 10 cc. of a 25% solution of BaCl₂ added, the Ba salt collected, the Ba removed with H₂SO₄, and the filtrate concentrated to give (on cooling) tan crystals (VII), m. 171-5° (decomposition). VII (0.55 g.) in 5 cc. MeOH and 5 cc. H₂SO₄ was refluxed 15 h., the mixture diluted with water, made alk. with Na₂CO₃, extracted with EtOAc, and the extract dried, filtered, and evaporated to dryness, yielding 0.4 g. 2,3-dicarbomethoxypyrazine (VIII), m. 55-6°. To 29 cc. 48% HBr (cooled, ice-NaCl) were added consecutively 8.7 g. IV, 7.6 cc. Br, 8.7 g. NaNO₂ in 15 cc. water, and 19 g. NaOH in 50 cc. water to give 7.8 g. 2,5-dibromopyrazine (IX), m. 47-8° (from water-EtOH, 2:1). 2,5-Dicarbomethoxypyrazine, prepared from IX by a method similar to that used for the preparation of VIII, m. 169.5-70.1° (from MeOH). In the experiment, the researchers used many compounds, for example, 5-Aminopyrazine-2-carboxamide (cas: 89323-09-1Quality Control of 5-Aminopyrazine-2-carboxamide).

5-Aminopyrazine-2-carboxamide (cas: 89323-09-1) belongs to pyrazine derivatives. Pyrazines are volatile compounds that are used in the cosmetic, food, flavor, and fragrance industries. A number of pyrazine-based derivatives were used as dyes or fluorescent probes.Quality Control of 5-Aminopyrazine-2-carboxamide

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reductones and tricarbonyl compounds XXI. Reactions of dehydroascorbic acid and of other 2,3-dioxobutyrolactones with o-phenylenediamine was written by Dahn, H.;Moll, H.. And the article was included in Helvetica Chimica Acta in 1964.Category: pyrazines This article mentions the following:

2,3-Dioxo-γ-lactones react with ο-C₆H₄(NH₂) ₂ at both oxo groups and also at the lactone CO groups. Structures of condensation products were investigated. Reaction of 2 g. 4-phenyl-2,3-dioxobutyrolactone hydrate (Ia) in 200 ml. 6N HCl at room temperature with 3 g. ο-C₆H₄-(NH₂)₂ yields 96% 3-(α-hydroxybenzyl)quinoxaline-2-carboxylic acid lactone (IIa), m. 184° (aqueous Me₂CO). A suspension of 700 mg. IIa in 25 ml. MeOH is saturated at room temperature with NH₃ to yield 97% the corresponding amide, m. 152-3° (aqueous MeOH), which is readily reconverted by stirring at room temperature with 2N HCl or dilute AcOH into IIa. Refluxing I g. IIa in 25 ml. MeOH with 1 ml. PhNHNH₂ gives 1.2 g. 3-(α-hydroxybenzyl)quinoxaline-2-carboxylic acid phenylhydrazide, m. 188° (decomposition) (MeOH), which (1 g.) is refluxed in 25 ml. 2N NaOH 1 hr. under N to give BzH and 400 mg. quinoxaline-2-carboxylic acid (IV), m. 215-20° (decarboxylation) (H₂O). Refluxing 1 g. Ia with 1.1 g. O-C₆H₄(NH₂)₂ in 25 min. EtOH 25 min. gives 75% 2′-amino-3-(α-hydroxybenzyl)quinoxaline-2-carboxanilide (IIIa), m. 193-4° (decomposition), which is converted into 98% IIa by treating with 50 ml. 2N HCl 30 min. at room temperature Reaction of 1 g. IIIa with 10 ml. Ac₂O in 10 ml. HCONMe₂ (DMF) yields 81% the N-Ac derivative, m. 174-5°, which is readily hydrolyzed to IIa in 94% yield by refluxing 0.5 g. in 15 ml. EtOH and 15 ml. 2N HCl 10 min. Analogously, condensation of 2 g. 4-(p-methoxyphenyl)-2,3-dioxobutyrolactone hydrate (Ib), m. 146.8°, with 1 g. o-C₆H₄-(NH₂)₂ gives in acid medium 90% IIb, m. 165°, and in neutral EtOH 80% IIIb, m. 180° (decomposition). Dehydroascorbic acid (Ic) and 0-C₆H₄(NH₂)₂, forms in neutral solution 98% IIIc, m. 177°, which is converted in 65% yield into a yellow modification, m. 178°, by refluxing in anhydrous MeOH. Acetylation of IIIc with Ac₂O in DMF gives the corresponding N-Ac derivative, m. 191° (decomposition), which yields on hydrolysis with 0.5N HCl at 5° 60%. IIc, m. 187° (decomposition). The ir spectra of the compounds are discussed. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Category: pyrazines).

Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine heterocycles and their benzo derivatives possess many interesting properties, including chemical reactivity profiles, and have diverse applications in total synthesis, medicine, chemical biology, materials, dyes, and imaging. Substituted pyrazines have been found as subunits of multiple synthetically constructed therapeutic agents, as well as several natural products.Category: pyrazines

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem