Tag: 100-200

Synthesis and antithrombogenicity assessment of tetramethylpyrazine-capped poly(ethylene glycol) was written by Cui, Dongmei;Wang, Song;Xia, Chengjian;Zhu, Hesun. And the article was included in Key Engineering Materials in 2005.Product Details of 75907-74-3 This article mentions the following:

Tetramethylpyrazine(TMPZ) is an active ingredient of a Chinese herbal medicine Chuanxiong (Ligusticum wallichii Franchat). In order to enhance its stability and delivery in vivo TMPZ-capped poly(ethylene glycol) conjugate was designed and synthesized efficiently by the condensation reaction of 2-carboxyl-3, 5, 6-trimethylpyrazine (TMPZCOOH) with PEG(M = 2000) in the presence of dicyclohexylcarbodiimide (DCCI). The TMPZ-PEG conjugate obtained was then purified by gel filtration chromatog. (SephadexG-15 column, 1.6×100cm; eluent: distilled water) and characterized by FTIR, UV spectra. FTIR (KBr): 2868cm^-1(CH₂), 1718cm^-1 (C=O), 1455cm^-1 (-C=N-), 1113cm^-1(O-CH₂-CH₂). The degree of end-capping of TMPZ per PEG mols. was estimated to be 87% from UV absorbance at 294 nm. The anticoagulant activity of the conjugate was evaluated by in vitro coagulation time test. The result showed that the activated partial thromboplastin time (APTT) of the TMPZ-PEG conjugate is nearly equal to that of blank plasma in our experiment conditions, this behavior is similar to that of TMPZ. But TMPZCOOH, one of the main metabolic products of TMPZ in vivo, exhibited more potent anticoagulant activity than TMPZ and TMPZ-PEG, its APTT is even larger than the maximum clotting time set by the instrument. It is also found that APTT of the conjugate increased as the time of the sample stayed in water bath at 37°. This is probably because the ester bond between TMPZCOOH and PEG hydrolyzed during the stay time and released the free TMPZCOOH. In the experiment, the researchers used many compounds, for example, (3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3Product Details of 75907-74-3).

(3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3) belongs to pyrazine derivatives. Pyrazine has the elements of symmetry for the point group D2h. It has three mutually perpendicular two-fold axes. It also has three mutually perpendicular planes of symmetry. As a result, pyrazine also has a centre of symmetry. 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.Product Details of 75907-74-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Ring transformations of heterocyclic halo compounds with nucleophiles. XL. Pteridine studies. Part V. Dual reactivity of 2-chloro-4,6,7-triphenylpteridine and 6-chloropyrido[2,3-b]pyrazine towards potassium amide in liquid ammonia was written by Nagel, A.;Van der Plas, H. C.. And the article was included in Tetrahedron Letters in 1978.HPLC of Formula: 322-46-3 This article mentions the following:

The pteridine I (X = N, R = Cl, R¹ = Ph) reacted with KNH₂ in NH₃(l) to give the aminodechlorinated product I (X = N, R = NH₂, R¹ = Ph) and the dechlorinated product I (X = N, R = H, R¹ = Ph). Labeling studies showed that the aminodechlorination proceeds by a ring opening-ring closure sequence which implies that the 2-chloro substituent of I (i.e. R) directs the attack of the nucleophile exclusively to C-4. The reaction of the pyrazine I (X = CH, R = Cl, R¹ = H) with KNH₂ in NH₃(l) was studied; I (X = CH, R = R¹ = H) and the imidazopyridine II were obtained in a 1:3 ratio. The mechanism of this ring contraction is discussed and a reaction scheme postulated. 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. Pyrazine-based skeletons were incorporated into agents targeting a range of ailments. Many derivatives were synthesized and evaluated as potential cancer treatments.HPLC of Formula: 322-46-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Reduction of different electron-poor N-heteroarylhydrazines in strong basic conditions was written by Unciti-Broceta, Asier;Pineda de las Infantas, Maria J.;Gallo, Miguel A.;Espinosa, Antonio. And the article was included in Chemistry – A European Journal in 2007.Electric Literature of C7H5N3 This article mentions the following:

The 1st application of the Wolff-Kishner reduction methodol. to electron-poor heteroaromatic compounds is reported. Hydrazino-containing heterocycles with hydrazone-type tautomery were reduced under basic conditions. This novel chem. was successfully applied to mono-dehalogenate a number of electron-poor heterocycles in a regioselective manner, e.g. 2,6-dichloropurine to 2-chloropurine. According to the exptl. results, this reductive process is a base-catalyzed reaction that takes only place in the presence of air, probably through an oxygen-assisted mechanism. As a consequence of the specific features of this kind of hydrazone/enehydrazine tautomers, the overall outcome of the process is the synthesis of a Shapiro-type reduction product by simply using a milder version of the Huang-Minlon methodol. The crystal and mol. structures of 2-propoxypyrido[2,3-b]pyrazine were determined by x-ray crystallog. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Electric Literature of C7H5N3).

Pyrido[2,3-b]pyrazine (cas: 322-46-3) 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 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.Electric Literature of C7H5N3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Hybrid molecules of scutellarein and tertramethylpyrazine’s active metabolites for ischemic stroke was written by Dong, Yongxi;Zhang, Xiaohe;Liu, Mingji;Yang, Yang;Guo, Ting;Mao, Yuanhu;Zhang, Jiquan;Fu, Xiaozhong;Zhao, Yonglong;Chen, Jinglei;Dong, Li;Qiao, Chunhua. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2019.Recommanded Product: (3,5,6-Trimethylpyrazin-2-yl)methanol This article mentions the following:

A series of hybrid mols. of scutellarein and tertramethylpyrazine’s active metabolites have been synthesized. Compared to the original compound, these prepared compounds exhibited higher water solubility, more appropriate logP and better stability. Importantly, compounds I [R = Me, iBu, sec-Bu] showed improved neuroprotective activity against the H₂O₂-induced cell death in PC12 cells, and better antithrombosis activity. The optimized compound I [R = Me] was further evaluated by cerebral ischemia/ reperfusion in the middle cerebral artery occlusion (MCAO) model, the results showed that the compound could significantly reduce the infarct area and decrease the neuronal cell damage in CA1 pyramidal neurons. Overall, we demonstrated that the twin drug strategy could be applied in the development of agents for the treatment of ischemic stroke. In the experiment, the researchers used many compounds, for example, (3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3Recommanded Product: (3,5,6-Trimethylpyrazin-2-yl)methanol).

(3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3) 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. 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.Recommanded Product: (3,5,6-Trimethylpyrazin-2-yl)methanol

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthesis and antithrombogenicity assessment of tetramethylpyrazine-polyacrylic acid conjugate was written by Lin, Nini;Wang, Song;Zhu, Hesun. And the article was included in Gaojishu Tongxun in 2005.Computed Properties of C8H12N2O This article mentions the following:

To enhance the stability and delivery in vivo of tetramethylpyrazine (TMPZ), TMPZ-polyacrylic acid (PAA) conjugate was designed and synthesized efficiently by the condensation reaction of 2,5-dihydroxymethyl-3,6-dimethylpyrazine (TMPZD2) with PAA (M = 1000) in the presence of dicyclohexylcarbodiimide (DCCI). The TMPZ-PAA conjugate was then purified and characterized by FT-IR, UV spectra. The percentage of TMPZ in the sample was 29.4% from UV absorbance at 294 nm. The anticoagulant activity of the conjugate was evaluated by in vitro coagulation time test and platelet aggregation. The APTT, PT, TT, and the time of platelet aggregation of the TMPZ-PAA conjugate took longer than those of control, exhibiting better blood anticoagulant activity. The mechanism of antithrombogenicity of TMPZ-PAA conjugate was discussed. In the experiment, the researchers used many compounds, for example, (3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3Computed Properties of C8H12N2O).

(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 number of pyrazine-based derivatives were used as dyes or fluorescent probes.Computed Properties of C8H12N2O

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Unified Approach to Decarboxylative Halogenation of (Hetero)aryl Carboxylic Acids was written by Chen, Tiffany Q.;Pedersen, P. Scott;Dow, Nathan W.;Fayad, Remi;Hauke, Cory E.;Rosko, Michael C.;Danilov, Evgeny O.;Blakemore, David C.;Dechert-Schmitt, Anne-Marie;Knauber, Thomas;Castellano, Felix N.;MacMillan, David W. C.. And the article was included in Journal of the American Chemical Society in 2022.HPLC of Formula: 912773-21-8 This article mentions the following:

A general catalytic method for direct decarboxylative halogenation of (hetero)aryl carboxylic acids RC(O)OH (R = 4-sulfamoylphenyl, 5-methylpyridin-2-yl, isoquinolin-1-yl, etc.) via ligand-to-metal charge transfer was reported. This strategy accommodates an exceptionally broad scope of substrates. An aryl radical intermediate is leveraged toward divergent functionalization pathways: (1) atom transfer to access bromo- or iodo(hetero)arenes or (2) radical capture by copper and subsequent reductive elimination to generate chloro- or fluoro(hetero)arenes. The proposed ligand-to-metal charge transfer mechanism is supported through an array of spectroscopic studies. In the experiment, the researchers used many compounds, for example, 2-Bromo-5-chloropyrazine (cas: 912773-21-8HPLC of Formula: 912773-21-8).

2-Bromo-5-chloropyrazine (cas: 912773-21-8) 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. 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.HPLC of Formula: 912773-21-8

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Hydrophobicity parameters determined by reversed-phase liquid chromatography. IV. Shortcoming of log K_W approach for prediction of log P of pyrazines was written by Yamagami, Chisako;Takao, Narao. And the article was included in Chemistry Express in 1991.Related Products of 6924-68-1 This article mentions the following:

The capacity factors of monosubstituted pyrazines on a C18-modified column were measured. The observed and extrapolated log k_W (capacity factor in 100% water) values were compared with log P. The results suggested that the conventional log k_W approach would not be applicable in the prediction of the log P value of polar solutes. 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. Pyrazines are part of several biologically active polycyclic compounds; examples are quinoxalines, phenazines; and the bio-luminescent natural products pteridines, flavins, and their derivatives. Pyrazine-based skeletons were incorporated into agents targeting a range of ailments. Many derivatives were synthesized and evaluated as potential cancer treatments.Related Products of 6924-68-1

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Sulfur(IV)-Mediated Unsymmetrical Heterocycle Cross-Couplings was written by Zhou, Min;Tsien, Jet;Qin, Tian. And the article was included in Angewandte Chemie, International Edition in 2020.Formula: C4H2BrFN2 This article mentions the following:

Despite the tremendous utilities of metal-mediated cross-couplings in modern organic chem., coupling reactions involving nitrogenous heteroarenes remain a challenging undertaking – coordination of Lewis basic atoms into metal centers often necessitate elevated temperature, high catalyst loading, etc. Herein, the authors report a sulfur (IV) mediated cross-coupling amendable for the efficient synthesis of heteroaromatic substrates. Addition of heteroaryl nucleophiles to a simple, readily-accessible alkyl sulfinyl (IV) chloride gave a trigonal bipyramidal sulfurane intermediate. Reductive elimination therefrom provides bis-heteroaryl products in a practical and efficient fashion. In the experiment, the researchers used many compounds, for example, 2-Bromo-5-fluoropyrazine (cas: 1209459-10-8Formula: C4H2BrFN2).

2-Bromo-5-fluoropyrazine (cas: 1209459-10-8) 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). 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.Formula: C4H2BrFN2

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Hydrophobicity parameters determined by reversed-phase liquid chromatography. XII. Comparison of capacity factors and octane/methanol-water partition coefficients for monosubstituted pyrazines, and effect of octanol added to both partitioning systems was written by Yamagami, Chisako;Iwasaki, Kaname;Ishikawa, Ayako. And the article was included in Chemical & Pharmaceutical Bulletin in 1997.Application In Synthesis of Ethyl pyrazine-2-carboxylate This article mentions the following:

Partition coefficients (P) of pyrazine and its COOMe derivative (strong hydrogen bond acceptor), were measured for the octane/aqueous methanol partitioning system (P_O/MW) at different methanol (MeOH) concentrations and the dependence of log P_O/MW on the methanol concentration was compared to the corresponding change in log k’ (k’: capacity factor) obtained by reversed-phase liquid chromatog. with aqueous methanol. Next, in order to make the chromatog. system approx. more closely to the octanol/water partitioning system, a small quantity of octanol was added to the eluents and also to the octane/aqueous methanol partitioning system and further comparisons were made. It was found that the octanol effect was min. at 50% MeOH, suggesting that the chromatog. system with eluents containing about 50% MeOH has properties more similar to the octanol/water partitioning system than with eluents of other compositions This confirms our previous result that the log k’ parameter obtained at 50% MeOH yields a better correlation with log P_oct (P_oct: octanol/water partition coefficient) than those obtained at other mobile phase compositions in the range from 5 to 70% MeOH. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Application In Synthesis of Ethyl pyrazine-2-carboxylate).

Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) 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. 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.Application In Synthesis of Ethyl pyrazine-2-carboxylate

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Pi-electron delocalization in aza derivatives of naphthalene and indole was written by Mohajeri, Afshan;Shahamirian, Mozhgan. And the article was included in Computational & Theoretical Chemistry in 2011.Reference of 322-46-3 This article mentions the following:

The influence of increasing number of nitrogens and their sequences on π-electron delocalization of aza derivatives of naphthalene and indole was studied using different quant. descriptors including the geometry-based harmonic oscillator model of aromaticity (HOMA), magnetic index nucleus independent chem. shift (NICS) and electronic indexes. Also the authors used HOMO-LUMO gap and anisotropy of magnetic susceptibility as global descriptors. N-N bond destabilizes both endosubstituted naphthalenes and indoles and the most stable isomers are those having smallest number of such units. All studied indexes except HOMA indicate aromaticity lowering with an increase of the number of N atoms in a ring, however, the anomaly high aromatic characters are observed for the cases when N-N bond is formed. Anal. of at. charge d. shows that the maximum local aromaticity belongs to position isomer in which the average over at. charges on heteroatoms is less in the individual rings. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Reference of 322-46-3).

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. Pyrazine-based skeletons were incorporated into agents targeting a range of ailments. Many derivatives were synthesized and evaluated as potential cancer treatments.Reference of 322-46-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem