Heterocyclic Building Blocks-quinoxaline

Zhang, Xingjie; Xia, Aiyou; Chen, Haoyi; Liu, Yuanhong published the artcile< General and Mild Nickel-Catalyzed Cyanation of Aryl/Heteroaryl Chlorides with Zn(CN)2: Key Roles of DMAP>, Related Products of 23088-24-6, the main research area is aryl halide zinc cyanide nickel DMAP; cyanoarene preparation; heteroaryl halide zinc cyanide nickel DMAP; cyanoheteroarene preparation; nickel cyanation catalyst; DMAP cyanation mediator.

A new and general nickel-catalyzed cyanation of hetero(aryl) chlorides using less toxic Zn(CN)2 as the cyanide source has been developed. The reaction relies on the use of inexpensive NiCl2·6H2O/dppf/Zn as the catalytic system and DMAP as the additive, allowing the cyanation to occur under mild reaction conditions (50-80 °C) with wide functional group tolerance. DMAP was found to be crucial for successful transformation, and the reaction likely proceeds via a Ni(0)/Ni(II) catalysis based on mechanistic studies. The method was also successfully extended to aryl bromides and aryl iodides.

Organic Letters published new progress about Aromatic nitriles Role: SPN (Synthetic Preparation), PREP (Preparation). 23088-24-6 belongs to class quinoxaline, and the molecular formula is C9H5N3, Related Products of 23088-24-6.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Lassagne, Frederic; Dugueperoux, Camille; Roca, Carlos; Perez, Concepcion; Martinez, Ana; Baratte, Blandine; Robert, Thomas; Ruchaud, Sandrine; Bach, Stephane; Erb, William; Roisnel, Thierry; Mongin, Florence published the artcile< From simple quinoxalines to potent oxazolo[5,4-f]quinoxaline inhibitors of glycogen-synthase kinase 3 (GSK3)>, Quality Control of 6272-25-9, the main research area is oxazoloquinoxaline preparation glycogen synthase kinase inhibition kinetic SAR docking.

2,7-Disubstituted oxazolo[5,4-f]quinoxalines were synthesized from 6-amino-2-chloroquinoxaline in four steps (iodination at C5, substitution of the chloro group, amidation and copper-catalyzed cyclization) affording 28 to 44% overall yields. 2,8-Disubstituted oxazolo[5,4-f]quinoxaline was similarly obtained from 6-amino-3-chloroquinoxaline (39% overall yield). For the synthesis of other oxazolo[5,4-f]quinoxalines, amidation was rather performed before substitution; moreover, time-consuming purification steps were avoided between the amines and the final products (38 to 54% overall yields). Finally, a more efficient method involving merging of the last two steps in a sequential process was developed to access more derivatives (37 to 65% overall yields). Most of the oxazolo[5,4-f]quinoxalines were evaluated for their activity on a panel of protein kinases, and a few 2,8-disubstituted derivatives proved to inhibit GSK3 kinase. While experiments showed an ATP-competitive inhibition on GSK3β, structure-activity relationships allowed us to identify 2-(3-pyridyl)-8-(thiomorpholino)oxazolo[5,4-f]quinoxaline as the most potent inhibitor with an IC50 value of about 5 nM on GSK3α.

Organic & Biomolecular Chemistry published new progress about Amidation. 6272-25-9 belongs to class quinoxaline, and the molecular formula is C8H4ClN3O2, Quality Control of 6272-25-9.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Lewis, Susan J.; Mirrlees, Margaret S.; Taylor, Peter J. published the artcile< Rationalizations among heterocyclic partition coefficients. Part 2: The azines>, Safety of 6-Quinoxalinecarbonitrile, the main research area is azine structure partition coefficient; LFER azine.

π-Values (partition substituent constants) of 246 azines are given and discussed in terms of Δπ, the difference in π-value from that expected for C6H6. It is shown that Δπ is close to zero for alkyl and most halogen groups, but for polar substituents capable of H bonding it may be as high as φ1.6. Except for peri-positions, these Δπ-values may be correlated by a set of equations specific for different types of substituent position and containing terms which sep. parameterize proton-donor and -acceptor ability. The rationale behind this treatment is justified in terms of the nature of the octanol-H2O partitioning process and the manner in which electronic effects are expected to operate, in this context and that of the individual mol. Other topics discussed include: reasons for deviations among “”irregular”” substituents; the special problems of peri-positions; multisubstitution; and some consequences of this anal. for other types of compound

Quantitative Structure-Activity Relationships published new progress about Molecular structure-property relationship, partition. 23088-24-6 belongs to class quinoxaline, and the molecular formula is C9H5N3, Safety of 6-Quinoxalinecarbonitrile.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

McQuaid, Loretta A.; Smith, Edward C. R.; South, Kimberly K.; Mitch, Charles H.; Schoepp, Darryle D.; True, Rebecca A.; Calligaro, David O.; O’Malley, Patrick J.; Lodge, David; Ornstein, Paul L. published the artcile< Synthesis and excitatory amino acid pharmacology of a series of heterocyclic-fused quinoxalinones and quinazolinones>, Quality Control of 6272-25-9, the main research area is amino acid antagonist condensed quinoxalinone; triazoloquinoxalinone amino acid antagonist; tetrazoloquinoxalinone amino acid antagonist; pyrazoloquinazolinone amino acid antagonist.

A series of substituted 1,2,4-triazolo[4,3-a]quinoxalin-4(5H)-ones I (R1 = R2 = Cl, F, R3 = H, alkyl, Ph; R1 = NO2, R2 = H, NO2, R3 = H), tetrazolo[1,5-a]quinoxalin-4(5H)-ones II (R = R2 = Cl, H, NO2; R1 = NO2, R2 = H; R1 = H, R2 = NO2), pyrazolo[1,5-c]quinazolin-5(6H)-ones III, and an imidazo[1,2-a]quinoxalin-4(5H)-one, was synthesized as potent amino acid antagonists. In general, the same heterocycles which demonstrated the best affinity for the AMPA receptor also demonstrated the best affinity for the glycine site on the NMDA receptor complex. 1-Propyl-7,8-dichloro-1,2,4-triazolo[4,3-a]quinoxalin-4(5H)-one, was found to bind with the greatest affinity to the AMPA receptor with an IC50 of 0.83 μM and antagonized 40 μM AMPA-induced depolarization in the cortical slice preparation with an IC50 of 44 μM. 7,8-Dichloro-1,2,4-triazolo[4,3-a]quinoxalin-4(5H)-one and 7,8-dichloroimidazo[1,2-a]quinoxalin-4(5H)-one possessed the best affinity for the glycine site with IC50 values of 0.63 and 1.25 μM, resp. The structure-activity relationship for the heterocyclic compounds did not directly parallel that of known quinoxalinediones (e.g. DNQX and DCQX) at the AMPA receptor nor that of the kynurenic acids at the glycine site on the NMDA receptor complex.

Journal of Medicinal Chemistry published new progress about Excitatory amino acids Role: BIOL (Biological Study). 6272-25-9 belongs to class quinoxaline, and the molecular formula is C8H4ClN3O2, Quality Control of 6272-25-9.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Hoang, Thanh T.; To, Tuong A.; Cao, Vi T. T.; Nguyen, Anh T.; Nguyen, Tung T.; Phan, Nam T. S. published the artcile< Direct oxidative C-H amination of quinoxalinones under copper-organic framework catalysis>, Related Products of 89898-96-4, the main research area is copper organic framework catalyst preparation green chem; quinoxalinone amine carbon hydrogen activation amination; aminoquinoxalinone preparation.

A copper-organic framework Cu-CPO-27 was synthesized, and utilized as a recyclable heterogeneous catalyst for the direct C-H amination of quinoxalin-2(1H)-ones with amines to produce 3-aminoquinoxalin-2(1H)-ones, e.g., I. High yields were achieved in the presence of mol. oxygen as the oxidant. This framework was more catalytically active than a number of MOF-based catalysts. The Cu-CPO-27 also displayed higher performance than CuFe2O4 nanoparticles. The copper-organic framework catalyst could be reutilized in the synthesis of 3-aminoquinoxalin-2(1H)-ones via the direct C-H amination reaction without a remarkable deterioration in catalytic performance. This is the first heterogeneous catalytic protocol to generate 3-aminoquinoxalin-2(1H)-ones.

Catalysis Communications published new progress about Amination. 89898-96-4 belongs to class quinoxaline, and the molecular formula is C8H5N3O3, Related Products of 89898-96-4.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Jo, Hakryul; Patterson, Victoria; Stoessel, Sean; Kuan, Chia-Yi; Hoh, Josephine published the artcile< Protoporphyrins enhance oligomerization and enzymatic activity of HtrA1 serine protease>, Related Products of 163769-88-8, the main research area is protoporphyrin oligomerization HtrA1 serine protease protoporphyria hemin.

High temperature requirement protein A1 (HtrA1), a secreted serine protease of the HtrA family, is associated with a multitude of human diseases. However, the exact functions of HtrA1 in these diseases remain poorly understood. We seek to unravel the mechanisms of HtrA1 by elucidating its interactions with chem. or biol. modulators. To this end, we screened a small mol. library of 500 bioactive compounds to identify those that alter the formation of extracellular HtrA1 complexes in the cell culture medium. An initial characterization of two novel hits from this screen showed that protoporphyrin IX (PPP-IX), a precursor in the heme biosynthetic pathway, and its metalloporphyrin (MPP) derivatives fostered the oligomerization of HtrA1 by binding to the protease domain. As a result of the interaction with MPPs, the proteolytic activity of HtrA1 against Fibulin-5, a specific HtrA1 substrate in age-related macular degeneration (AMD), was increased. This phys. interaction could be abolished by the missense mutations of HtrA1 found in patients with cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). Furthermore, knockdown of HtrA1 attenuated apoptosis induced by PPP-IX. These results suggest that PPP-IX, or its derivatives, and HtrA1 may function as co-factors whereby porphyrins enhance oligomerization and the protease activity of HtrA1, while active HtrA1 elevates the pro-apoptotic actions of porphyrin derivatives Further anal. of this interplay may shed insights into the pathogenesis of diseases such as AMD, CARASIL and protoporphyria, as well as effective therapeutic development.

PLoS One published new progress about Age-related macular degeneration. 163769-88-8 belongs to class quinoxaline, and the molecular formula is C22H21N3O2, Related Products of 163769-88-8.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Lee, Hong Geun; Milner, Phillip J.; Placzek, Michael S.; Buchwald, Stephen L.; Hooker, Jacob M. published the artcile< Virtually Instantaneous, Room-Temperature [11C]-Cyanation Using Biaryl Phosphine Pd(0) Complexes>, Electric Literature of 23088-24-6, the main research area is cyanation carbon 11 aryl compound biaryl phosphine palladium catalyst; aryl nitrile carbon 11 labeled preparation.

A new radiosynthetic protocol for the preparation of [11C]aryl nitriles has been developed. This process is based on the direct reaction of in situ prepared L·Pd(Ar)X complexes (L = biaryl phosphine) with [11C]HCN. The strategy is operationally simple, exhibits a remarkably wide substrate scope with short reaction times, and demonstrates superior reactivity compared to previously reported systems. With this procedure, a variety of [11C]nitrile-containing pharmaceuticals, e.g., [11C]citalopram, were prepared with high radiochem. efficiency.

Journal of the American Chemical Society published new progress about Aromatic nitriles Role: SPN (Synthetic Preparation), PREP (Preparation) ([11C]-labeled). 23088-24-6 belongs to class quinoxaline, and the molecular formula is C9H5N3, Electric Literature of 23088-24-6.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Xu, Xinyu; Chen, Kezhi published the artcile< Palladium-catalyzed C-H activation of anisole with electron-deficient auxiliary ligands: a mechanistic investigation>, Category: quinoxaline, the main research area is anisole iodobenzene arylation mechanism PES Hammett constant.

Palladium-catalyzed selective C-H activation-functionalization has shown its significance in organic transformations. Recently, Yu et al. reported a palladium-norbornene co-catalyzed meta-selective arylation of electron-rich arenes. Although the exptl. observed site-selectivity has been successfully explained by the computational work of Dongju Zhang and co-workers, some important exptl. factors, such as the ligand choice and narrow substrate scope, remain unrationalized. In contrast to what has been suggested by Dongju Zhang, we proposed the palladium-silver dinuclear species as reactive intermediates in this work. The substituent effect was estimated to unravel the e-CMD nature of the rate-determining C-H activation step. Based on this realization, the exptl. observed substrate scope and ligand choice have also been rationalized.

Organic & Biomolecular Chemistry published new progress about Arylation catalysts. 23088-24-6 belongs to class quinoxaline, and the molecular formula is C9H5N3, Category: quinoxaline.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Minisci, Francesco; Recupero, Francesco; Punta, Carlo; Gambarotti, Cristian; Antonietti, Fabrizio; Fontana, Francesca; Pedulli, Gian Franco published the artcile< A novel, selective free-radical carbamoylation of heteroaromatic bases by Ce(IV) oxidation of formamide, catalyzed by N-hydroxyphthalimide>, Related Products of 5182-90-1, the main research area is carbamoylation heteroaromatic compound cerium oxidation formamide hydroxyphthalimide catalyst.

The Ce(IV)-NHPI system was used to generate a carbamoyl radical by oxidation of formamide; this nucleophilic radical has been successfully used in the carbamoylation of heteroaromatic bases.

Chemical Communications (Cambridge, United Kingdom) published new progress about Carbamoylation. 5182-90-1 belongs to class quinoxaline, and the molecular formula is C9H7N3O, Related Products of 5182-90-1.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider

Makaravage, Katarina J.; Shao, Xia; Brooks, Allen F.; Yang, Lingyun; Sanford, Melanie S.; Scott, Peter J. H. published the artcile< Copper(II)-Mediated [11C]Cyanation of Arylboronic Acids and Arylstannanes>, Formula: C9H5N3, the main research area is arylboronic acid cyanation copper; arylnitrile preparation; copper radiocyanation cyanation catalyst.

A copper-mediated method for the transformation of diverse arylboron compounds and arylstannanes to aryl-[11C]-nitriles is reported. This method is operationally simple, uses com. available reagents, and is compatible with a wide variety of substituted aryl- and heteroaryl substrates. This method is applied to the automated synthesis of high specific activity [11C]perampanel in 10% nondecay-corrected radiochem. yield (RCY).

Organic Letters published new progress about Arylboronic acids Role: RCT (Reactant), RACT (Reactant or Reagent). 23088-24-6 belongs to class quinoxaline, and the molecular formula is C9H5N3, Formula: C9H5N3.

Referemce:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider