Month: January 2023

Efficient quasi-solid-state dye-sensitized solar cells based on organic sensitizers containing fluorinated quinoxaline moiety was written by Jia, Xiaowei;Zhang, Weiyi;Lu, Xuefeng;Wang, Zhong-Sheng;Zhou, Gang. And the article was included in Journal of Materials Chemistry A: Materials for Energy and Sustainability in 2014.Recommanded Product: 5,8-Dibromoquinoxaline This article mentions the following:

Two novel organic sensitizers (FNE55 and FNE56) containing a 6,7-difluoroquinoxaline moiety were designed and synthesized for quasi-solid-state dye-sensitized solar cells (DSSCs). For comparison, an organic dye, FNE54, without fluorine has also been synthesized. The effects of the introduction of fluorine on the absorption, electrochem., and photovoltaic properties have been systematically investigated. Upon the incorporation of fluorine in the quinoxaline unit, the electron-withdrawing ability is strengthened, which results in the enhanced push-pull interactions and thus narrows the energy band gap. The absorption maximum wavelength in toluene solution bathochromically shifts from 504 nm for FNE54 to 511 nm for FNE55, and further to 525 nm for FNE56. However, although the lowest unoccupied MOs (LUMOs) are lowered down after the introduction of fluorines, the driving force for the photo-excited electrons from their excited states to the semiconductor conduction band is still sufficient. Consequently, the quasi-solid-state DSSC based on FNE56 exhibits a highest power conversion efficiency of 8.2%, which is 37% higher than that for FNE54 based quasi-solid-state DSSCs. In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3Recommanded Product: 5,8-Dibromoquinoxaline).

5,8-Dibromoquinoxaline (cas: 148231-12-3) 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.Recommanded Product: 5,8-Dibromoquinoxaline

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

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

Pyrazinoates as antiparasitic agents against Trypanosoma cruzi was written by Vasconcelos, Camilla I.;Varela, Marina T.;Torrecilhas, Ana C.;Fernandes, Joao P. S.. And the article was included in Archiv der Pharmazie (Weinheim, Germany) in 2018.Formula: C7H8N2O2 This article mentions the following:

This work reports a repurposing study of pyrazinoic acid (1) and Me (2), Et (3) and 2-chloroethyl (4) ester derivatives with antimycobacterial activity, in assays against Trypanosoma cruzi. The compounds and benznidazole, the standard antitrypanosoma drug, were evaluated in concentrations ranging from 100 to 6.25 μg/mL. The results showed that compounds 2 and 3 (EC₅₀ = 182 and 447 μM) significantly reduced the infection rate of the parasite into the mammalian cells at 100 μg/mL (p < 0.05) in a similar way to benznidazole. In addition, all the compounds also significantly reduced the number of intracellular parasites (compound 1 at 50 μg/mL, and compounds 2-4 at 100 μg/mL, p < 0.05) in comparison to the control. Compounds 1 and 2 were more effective than benznidazole at 50 μg/mL (p < 0.001). Moreover, compounds 1-4 did not show significant cytotoxicity against THP-1, J774, and HeLa cells (>1000 μM), indicating that they possess considerable selectivity against the parasites. This report represents the first study of such compounds against T. cruzi, indicating the potential of pyrazinoates as antiparasitic agents. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Formula: C7H8N2O2).

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. Pyrazines undergo nearly all of the same reactions as pyrimidines, from nucleophilic substitution (SNAr) to palladium-catalyzed cross coupling reactions.Formula: C7H8N2O2

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Preparation and Biofunctionalization of Multicolor Conjugated Polymer Nanoparticles for Imaging and Detection of Tumor Cells was written by Feng, Liheng;Liu, Libing;Lv, Fengting;Bazan, Guillermo C.;Wang, Shu. And the article was included in Advanced Materials (Weinheim, Germany) in 2014.Formula: C8H4Br2N2 This article mentions the following:

Multicolor conjugated polymer nanoparticles (CPNs) are designed and biofunctionalized with antibody for targeted cell imaging and cell detection. In comparison to single-antibody recognition mode to tumor cells, enhanced specificity for targeted imaging and detection of tumor cells is achieved by binding two antibody functionalized CPNs to one tumor cell. This strategy provides a new platform for designing CPNs useful for targeted imaging, cells detection and other biol. applications. In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3Formula: C8H4Br2N2).

5,8-Dibromoquinoxaline (cas: 148231-12-3) 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.Formula: C8H4Br2N2

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Substituent-directing effects in the homolytic acylation of pyrazine derivatives was written by Houminer, Y.;Southwick, E. W.;Williams, D. L.. And the article was included in Journal of Organic Chemistry in 1989.COA of Formula: C7H8N2O2 This article mentions the following:

The homolytic acylation of various monosubstituted pyrazines was studied for a wide spectrum of substituents. MeO and Cl substituents directed ortho to yield the corresponding 2,3-disbustituted pyrazines. Ac, CO₂Et, and CONH₂ groups directed para, leading to the corresponding 2,5-disubstituted pyrazines. These selectivities result from the combination of the inductive and resonance effects of the substituents. The synthetic potential of the acylation reaction is demonstrated in the preparation of some novel pyrazine flavorants, e.g., I. Thus, 2-chloropyrazine was treated with Me₂CHCHO, Me₃COOH, FeSO₄, and H₂SO₄ in H₂O to give (chloropyrazinyl)methylpropanone II. Treating furfuryl mercaptan with NaOEt and then II in EtOH gave 32% I. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1COA of Formula: C7H8N2O2).

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. Substituted pyrazines have been found as subunits of multiple synthetically constructed therapeutic agents, as well as several natural products.COA of Formula: C7H8N2O2

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Liquid chromatography-mass spectrometry method for determination of tetramethylpyrazine and its metabolite in dog plasma was written by Wang, Peng;Jin, Xin;Qi, Meiling;Fang, Lin. And the article was included in Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences in 2004.Product Details of 75907-74-3 This article mentions the following:

A liquid chromatog.-mass spectrometry method is described for the determination of tetramethylpyrazine (TMP) and its active metabolite, 2-hydroxymethyl-3,5,6-trimethylpyrazine (HTMP) in dog plasma. This method involves a plasma clean-up step using protein precipitation procedure followed by LC separation and pos. electrospray ionization mass spectrometry detection (ESI-MS). Chromatog. separation of the analytes was achieved on a C18 column using a mobile phase of methanol, water and acetic acid (50:50:0.6, volume/volume/v) at a flow rate of 1.0 mL/min. Selected ion monitoring (SIM) mode was used for analyte quantitation at m/z 137.2 for TMP, m/z 153.2 for HTMP and m/z 195.2 for caffeine. The linearity was obtained over the concentration ranges of 20-6000 ng/mL for TMP and 20-4000 ng/mL for HTMP and the lower limit of quantitation was 20 ng/mL for both analytes. For each level of QC samples, both inter- and intraday precisions (R.S.D.) were ≤7.4% for TMP and ≤6.0% for HTMP, and accuracy (R.E.) was ±6.0% for TMP and ≤3.5% for HTMP. The proposed LC-MS method was successfully applied to the pharmacokinetic studies of a TMP formulation preparation after oral administration to beagle dogs. 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. Pyrazines are volatile compounds that are used in the cosmetic, food, flavor, and fragrance industries. 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.Product Details of 75907-74-3

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

General Method for the Amination of Aryl Halides with Primary and Secondary Alkyl Amines via Nickel Photocatalysis was written by Song, Geyang;Nong, Ding-Zhan;Li, Jing-Sheng;Li, Gang;Zhang, Wei;Cao, Rui;Wang, Chao;Xiao, Jianliang;Xue, Dong. And the article was included in Journal of Organic Chemistry in 2022.Application of 912773-21-8 This article mentions the following:

It was reported that Ni(II)-bipyridine complex catalyzed efficient C-N coupling of aryl chlorides and bromides with various primary and secondary alkyl amines under direct excitation with light. Intramol. C-N coupling was also demonstrated. The feasibility and applicability of the protocol in organic synthesis was attested by more than 200 examples. In the experiment, the researchers used many compounds, for example, 2-Bromo-5-chloropyrazine (cas: 912773-21-8Application of 912773-21-8).

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

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Synthesis and biological evaluation of new tetramethylpyrazine-based chalcone derivatives as potential anti-Alzheimer agents was written by Wang, Meng;Qin, Hua-Li;Leng, Jing;Ameeduzzafar;Amjad, Muhammad Wahab;Raja, Maria Abdul Ghafoor;Hussain, Muhammad Ajaz;Bukhari, Syed Nasir Abbas. And the article was included in Chemical Biology & Drug Design in 2018.Application In Synthesis of (3,5,6-Trimethylpyrazin-2-yl)methanol This article mentions the following:

In the current study, a series of new ligustrazine-based chalcones was synthesized. For insertion of tetramethylpyrazine (TMP, also designated as ligustrazine) in chem. backbone of chalcone, a new ligustrazine-based aldehyde was prepared New ketones were synthesized for inclusion of quinazolin-4-yl amino and pyrazin-2-yl amino moieties. The newly synthesized compounds were screened for acetylcholinesterase, butyrylcholinesterase, and monoamine oxidases (MAO) inhibitory activities and also for in vitro cytotoxicity on PC12 cells. The effect of these compounds against amyloid β-induced cytotoxicity and aggregation was also investigated. The synthesized compounds effectively inhibited the related enzymes and also exhibited neuroprotective effects. Most of the compounds displayed better inhibitory potencies against Aβ aggregation than reference compounds Some compounds such as 11e and 16b showed very potent effects on multiple targets exhibiting behavior as multifunctional anti-Alzheimer agents. In the experiment, the researchers used many compounds, for example, (3,5,6-Trimethylpyrazin-2-yl)methanol (cas: 75907-74-3Application In Synthesis of (3,5,6-Trimethylpyrazin-2-yl)methanol).

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

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem

Infrared spectra of heterocyclic compounds. IV. Infrared spectra of monosubstituted pyridine derivatives was written by Shindo, Hideyo. And the article was included in Pharmaceutical Bulletin in 1957.Recommanded Product: Ethyl pyrazine-2-carboxylate This article mentions the following:

The infrared spectra were determined and the maximum frequencies tabulated for 2-, 3-, and 4-substituted pyridines, in which the substituents were NO₂, CN, Ac, CHO, CO₂Et, CONH₂, Br or Cl, C₅H₄N, Me, Et, MeO, and NH₂ (38 compounds). All the compounds were prepared by well-known methods: reduction of the corresponding N-oxides gave the 4-O₂N (m. 50°), 4-Cl (picrate, m. 144°), and 4-MeO (b₃₀ 92-4°) derivatives; perhydrol oxidation of the corresponding H₂N derivatives gave the 3- and 2-O₂N derivatives (m. 55° and 71°, resp.); ester condensation of the corresponding EtO₂C derivatives gave the 2- and 3-Ac derivatives (b. 190° and 220°, resp.); and the Gattermann reaction on 3-H₂N derivative gave the 3-Cl and 3-Br derivatives (b. 148-9° and 172-3°, resp.). The previously described exptl. method (C.A. 51, 5557b) for the infrared determinations was used. Results were discussed in their bearing on (1) the ring CH out-of-plane bending vibrations, which are in the region 700-900 cm.^-1 and can be interpreted as analogous to the corresponding substituted benzenes, (2) the ring double-bond stretching vibrations, which show 2 bands between 1550 and 1620 cm.^-1 that are directly related to the type of π-electron distribution on the ring, and (3) the electronic effect of ring N, which is shown as a frequency shift in the absorption of the substituent dependent upon its position in the ring. A series of weak absorptions at 990-1220 cm.^-1 was found to be very characteristic for the type of substitution. The linear correlations between the frequencies and σ-values of the substituents in benzene derivatives could be extended to these pyridine derivatives by using the σ-values of 0.93, 0.62, and 1.02, resp., for 4-, 3-, and 2-positions. In the experiment, the researchers used many compounds, for example, Ethyl pyrazine-2-carboxylate (cas: 6924-68-1Recommanded Product: Ethyl pyrazine-2-carboxylate).

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. 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: Ethyl pyrazine-2-carboxylate

Referemce:
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem