Month: January 2023

Synthesis and anti-platelet aggregation activity evaluation of ligustrazine derivatives was written by Fan, Lingling;Li, Yi;Wu, Xiaofang;Li, Yong;Zhang, Jue. And the article was included in Huaxue Tongbao in 2018.Safety of (3,5,6-Trimethylpyrazin-2-yl)methanol This article mentions the following:

Using ligustrazine (TMP) and o-phenylenediamine as raw materials, seven derivatives were synthesized via KMnO₄ oxidation, esterification, cyclization and reduction The structures were confirmed by ¹H NMR, ¹³C NMR and HRMS. The in vitro anti-platelet aggregation activities of the target compounds have been preliminarily tested by the Born turbidimetric method, and the exptl. results showed that compounds 3 (IC₅₀ = 0.23 mmol/L) and 7 (IC₅₀ = 0.27mmol/L) have significant inhibitory activity of against ADP (ADP) induced platelet aggregation, higher than that of ligustrazine (IC₅₀ = 0.42mmol/L). In the experiment, the researchers used many compounds, for example, (3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3Safety of (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. Pyrazines undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.Safety of (3,5,6-Trimethylpyrazin-2-yl)methanol

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthesis of the novel ligustrazine derivatives and their protective effect on injured vascular endothelial cell damaged by hydrogen peroxide was written by Liu, Xinyong;Zhang, Rui;Xu, Wenfang;Li, Chaowu;Zhao, Quanqin;Wang, Xingpo. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2003.Formula: C8H12N2O This article mentions the following:

A series of novel 2-acyloxymethyl-3,5,6-trimethylpyrazine derivatives, e.g. I (R = Ph), was designed and synthesized. Most compounds were found to be 1.5-4.5-fold higher potency than tetramethylpyrazine (TMP) in stimulating the proliferation of normal vascular endothelial cells and in protecting against hyperoxic acute injury. The most active one is I (RCO = 2-nicotinoyl) exhibiting the maximum proliferation rate (P_max) of 88.57% at the concentration of 0.1 mmol L^-1. Structure-activity relationships of these compounds were discussed. In the experiment, the researchers used many compounds, for example, (3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3Formula: C8H12N2O).

(3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3) 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 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: C8H12N2O

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Hydrophobicity parameters determined by reversed-phase liquid chromatography. I. Relationship between capacity factors and octanol-water partition coefficients for monosubstituted pyrazines and the related pyridines was written by Yamagami, Chisako;Ogura, Tamaki;Takao, Narao. And the article was included in Journal of Chromatography in 1990.Application of 6924-68-1 This article mentions the following:

The capacity factors (k‘) of monosubstituted pyrazines and 2-substituted pyridines were measured on a Capcellpack C₁₈ column using methanol-buffer (pH 9.2) mobile phases of different compositions, and the relationship between log P (n-octanol-water partition coefficient) and log k‘ was analyzed. In all instances the amphiprotic substituents were eluted faster than expected on the assumption of log P-log k‘ linearity, reflecting that these groups act as hydrogen donors. For other substituents, a good linear relationship between log P and log k‘ was obtained with eluents containing 50-70% (volume/volume) of methanol. However, as the methanol content decreased, linearity no longer held and correction terms for the electronic effects and specific effects attributed to ester and amide groups were required. The relationship between log k‘ (pyrazine) and log k‘ (pyridine) was studied by applying a modified bidirectional Hammett-type correction for the component in π-value attributable to electronic effects of substituents and aza functions on the hydrogen-bonding solvation effect. The retention behavior changes systematically with changes in mobile phase composition In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Application 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. A number of pyrazine-based derivatives were used as dyes or fluorescent probes.Application of 6924-68-1

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Dramatically enhanced fluorescence of heteroaromatic chromophores upon insertion as spacers into oligo(triacetylene)s was written by Edelmann, Michael J.;Raimundo, Jean-Manuel;Utesch, Nils F.;Diederich, Francois. And the article was included in Helvetica Chimica Acta in 2002.SDS of cas: 148231-12-3 This article mentions the following:

In continuation of a previous study on the modulation of π-electron conjugation of oligo(triacetylene)s by insertion of central hetero-spacer fragments between two (E)-hex-3-ene-1,5-diyne ((E)-1,2-diethynylethene, DEE) moieties, trimeric hybrid oligomers (I; A = spacer, R = SiEt₃, SiMe₃) were prepared Spacers used were both electron-deficient (quinoxaline-based heterocycles, pyridazine) and electron-rich (2,2′-bithiophene, 9,9-dioctyl-9H-fluorene)chromophores. With a dipyridophenazine spacer, transition metal complexes were synthesized as potential precursors for nanoscale scaffolding based on both covalent acetylenic coupling and supramol. assembly. The UV/visible spectra revealed that the majority of spacers provided heterotrimers featuring extended π-electron delocalization. The new hybrid chromophores show a dramatically enhanced fluorescence compared with the DEE dimer and homo-trimer. This increase in emission intensity appears as a general feature of these systems: even if the spacer mol. is nonfluorescent, the corresponding hetero-trimer may show a strong emission. The redox properties of the new hybrid chromophores were determined by cyclic voltammetry (CV) and rotating disk voltammetry (RDV). In each case, the first 1-electron reduction step in the hetero-trimers appeared anodically shifted compared with DEE dimer and homo-trimer. With larger spacer chromophore extending into two dimensions, the anodic shift (by 240-490 mV) seems to originate from inductive effects of the two strongly electron-accepting DEE substituents rather than from extended π-electron conjugation along the oligomeric backbone, as had previously been observed for DEE substituted porphyrins. In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3SDS of cas: 148231-12-3).

5,8-Dibromoquinoxaline (cas: 148231-12-3) 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 undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.SDS of cas: 148231-12-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Hydrophobicity parameters determined by reversed-phase liquid chromatography. XIV. Application of a new hydrogen-accepting scale of monosubstituted pyrazines to analysis of the relationship between octanol-water partition coefficients and retention factors measured in different mobile phases was written by Yamagami, Chisako;Haraguchi, Miyako. And the article was included in Chemical & Pharmaceutical Bulletin in 2000.HPLC of Formula: 6924-68-1 This article mentions the following:

The authors recently proposed a new H-accepting scale, S_HA, for monosubstituted pyrazines, and demonstrated that this parameter works effectively in expressing the relation between log P (P: 1-octanol/H₂O partition coefficient) and log k’ (k’: retention factor derived from reversed phase liquid chromatog.) with aqueous MeOH solutions as the mobile phase, according to the equation: log k’ = a log P+ρσ₁+sS_HA+constant, where σ₁ represents the electronic substituent constant The authors have extended the same treatment to anal. of log k’ measured in mobile phases containing different organic modifiers such as 1-propanol, MeCN, and dioxane, and found that the above equation is still useful. By comparing the correlations obtained, the parameter S_HA could be universally used for representing the difference in H-bonding effects involved in different partitioning systems. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1HPLC of Formula: 6924-68-1).

Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) belongs to pyrazine derivatives. Pyrazine is a symmetrical molecule with point group D2h. Pyrazine is less basic than pyridine, pyridazine and pyrimidine. Substituted pyrazines have been found as subunits of multiple synthetically constructed therapeutic agents, as well as several natural products.HPLC of Formula: 6924-68-1

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Chemotherapeutic studies on schistosomiasis. XXXVI. Synthesis of 4-phenyl- and 4-allyl-5-(2-pyrazinyl)-1,2,4-triazole-3-thione derivatives was written by Xu, Maoli;Lei, Xinghan. And the article was included in Yaoxue Xuebao in 1985.Quality Control of Ethyl pyrazine-2-carboxylate This article mentions the following:

Twenty-eight title compounds (I; R = Ph, allyl; R¹ = H, alkyl, acyl, dialkylaminomethyl, cyclic aminomethyl, etc.), effective schistosomicides at 1050 mg/kg in mice, were prepared Thus, heating 0.2 mol II (R² = EtO) with N₂H₄·H₂O in EtOH at 40-50° gave hydrazide II (R² = H₂NNH), which (0.075 mol) was heated with 0.09 mol PhNCS in EtOH at 110-50° to give 60-70% II (R² = PhNHCSNHNH) (III). Heating 0.08 mol III with 2 N NaOH at 70° gave 80-90% IV·Na (R = Ph), which (0.0045 mol) was heated with 0.0055 mol Me₂SO₄ in EtOH at 75° to give I (R = Ph, R¹ = H). In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Quality Control of Ethyl pyrazine-2-carboxylate).

Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) 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.Quality Control of Ethyl pyrazine-2-carboxylate

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Scavenging action to hydroxyl free radical of ligustrazine and it’s derivatives was written by Bian, Xiaoli;Chen, Xuemin;Liu, Yanxia;Pan, Qing. And the article was included in Zhongguo Yiyuan Yaoxue Zazhi in 2003.Reference of 75907-74-3 This article mentions the following:

The hydroxyl free radical scavenging activity of ligustrazine and its derivatives (2-hydromethyl-3,5,6- trimethylpyrazine, tetramethylpyrazine-N-monoxygen and tetramethylpyrazine-N-dioxygen) were evaluated using Fenton reaction to assay and calculate the concentration of compounds for scavenging 50% of hydroxyl free radicals (EC₅₀). In scavenging action to ·OH, a significant difference was observes between the ligustrazine as well as its derivatives and benzoic acid and mannitol (P <0.01), however, there was no apparent difference between ligustrazine and its derivatives (P >0.05). Ligustrazine and its derivatives had strong scavenging action to hydroxyl free radical. In the experiment, the researchers used many compounds, for example, (3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3Reference of 75907-74-3).

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

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthesis of substituted pyrazines derived from pyrazinecarboxaldehyde and hydroxymethylpyrazine was written by Piera, F.;Seoane, E.;Mestres, R.. And the article was included in Anales de Quimica (1968-1979) in 1979.SDS of cas: 6924-68-1 This article mentions the following:

From pyrazinecarboxylic and 2,3-pyrazinedicarboxylic esters were prepared from their acids. Pyrazinecarboxaldehyde (I) was obtained by LiAlH₄ reduction of Me pyrazinecarboxylate (II). Pyrazinylacrylates were obtained by Wittig reactions of I and alkyl pryazinyl carbinols by Grignard reactions of I. Pyrazinylmethacrolein was prepared by reducing pyrazinylmethacrylate to the alc. and MnO₂ oxidation NaBH₄ reduction of II gave pyrazinemethanol which when mesylated underwent a variety of substitution reactions. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1SDS of cas: 6924-68-1).

Ethyl pyrazine-2-carboxylate (cas: 6924-68-1) 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. A large number of pyrazine derivatives are known for their antitumor, antibiotic, anticonvulsant, antituberculosis, and diuretic activities.SDS of cas: 6924-68-1

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Excited singlet state absorption spectra and relaxation kinetics of the azanaphthalenes was written by Boldridge, David W.;Scott, Gary W.. And the article was included in Journal of Chemical Physics in 1986.Related Products of 322-46-3 This article mentions the following:

Picosecond excited-state singlet-singlet absorption spectra (S_n â†?S₁) and excited-state decay kinetics are reported for several diazanaphthalenes and a triazanaphthalene in room temperature solution New S_n (¹nπ^*) state energies were obtained empirically from these spectra. INDO-PSDCI mol. calculations were used to confirm the S_n â†?S₁ nature of the excited state transitions observed Decay rates were calculated from models based on a semiempirical mol. formalism, and these calculated rates were compared with the observed ones. Agreement of the calculated and observed rates are good except in cases of substantial nπ^*-ππ^* mixing of the actual excited states and in a particular case of high mol. symmetry (1,5-naphthyridine). In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Related Products of 322-46-3).

Pyrido[2,3-b]pyrazine (cas: 322-46-3) 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 undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.Related Products of 322-46-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Practical Approach for the Preparation of α-Keto Amides by Direct Aminocarbonylation of Carboxylic Esters with a Carbamoylsilane was written by Han, Yuling;Han, Shenghua;Ma, Jiangwen;Li, Weidong;Chen, Jianxin. And the article was included in Synlett in 2020.Related Products of 6924-68-1 This article mentions the following:

A novel and practical method has been developed for the preparation of α-keto amides e.g., Me 3-[(dimethylcarbamoyl)carbonyl]benzoate by a catalyst-free aminocarbonylation of carboxylic esters RC(O)OR¹ (R = CF₃, 4-nitrophenyl, 6-fluoropyridin-3-yl, pyrazin-2-yl, etc.; R¹ = Me, Et, Ph) with N,N-dimethylcarbamoyl(trimethyl)silane under neutral conditions. A new protocol for the synthesis of N,N-dimethyl-β-ethoxy-α,β-dioxo-propionamide was also developed by using this method. In the case of di-Et oxalate, only one ester group reacted selectively with 1.2 equiv of the N,N-dimethylcarbamoyl(trimethyl)silane, leading to the formation of N,N-dimethyl-β-ethoxy-α,β-dioxo-propionamide. The reaction was suitable for aryl, hetaryl, or open-chain esters containing strongly electron-withdrawing groups. 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. Pyrazines are chemical compounds (technically called “methoxypyrazinesâ€? found in grape skin and stems that are responsible for many “greenâ€?flavors in wine. Levels of pyrazines are dependent on viticultural practices, climate, and grape variety.Related Products of 6924-68-1

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem