Month: April 2022

The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Mechanism of aromatic side-chain reactions with special reference to the polar effects of substituents. IV. The mechanism of quaternary salt formation》. Authors are Baker, John W.; Nathan, Wilfred S..The article about the compound:1-(Bromomethyl)-4-ethylbenzenecas:57825-30-6,SMILESS:CCC1=CC=C(CBr)C=C1).Category: quinoxaline. Through the article, more information about this compound (cas:57825-30-6) is conveyed.

cf. C. A. 29, 4657.5. The following data are given for the reaction of RC6H4CH2Br with C5H5N in dry Me2CO at the temperatures given, where R is: p-Me, 20°, 2.020 (kp × 104, g.-mol./l./sec.); 40°, 7.983; p-Et, 20°, 1.811; 30°, 3.517; 40°, 6.733; p-iso-Pr, 20°, 1.633; 40°, 6.500; p-tert-Bu, 20°, 1.652; 30°, 3.357; 40°, 6.467; 2,4-Me2, 20°, 6.287; 30°, 12.48; 40°, 24.05; 2,4-(NO2)2, 20°, 2.288; 30°, 4.700; 40°, 8.960. The results show that the small retarding effect of a p-NO2 group is replaced by an accelerating effect when a 2nd NO2 group is introduced into the 2-position. In a series of substituents arranged in order of decreasing +I or increasing -I effects, a min. velocity is found with the p-NO2 compound: 2,4-Me2 > (p-tert-Bu < p-iso-Pr < p-Et < p-Me) > H > p-NO2 ≪ 2,4-(NO2)2. The position of the 2,4-(NO2)2 group illustrates a new phenomenon, viz., the occurrence of a min. velocity in a graded polar series without change in reaction kinetics. The interaction of the 2,4-dinitrobenzyl bromide with C5H5N is strictly bimol., the velocity coefficient in Me2CO at 40° being independent of the concentration The accelerating effect of the 2,4-(NO2)2 groups observed in dry Me2CO is almost absent in aqueous 90% Me2CO and becomes a retarding effect in aqueous 90% EtOH. The results thus far show (1) the reaction between benzyl halides and tert-bases in non-aqueous media is strictly bimol. and involves a simultaneous addition and dissociation; the Arrhenius energy of activation E is, within exptl. error, unaffected by substituents and is closely related to the energy changes involved in the electron cycle as a whole; the velocity of the reaction, as affected by substituent groups in the aryl bromide, is determined mainly by some factor which is incorporated in the term P of the equation kp = PZe-E/RT; electron accession toward the side chain (+I effect) increases the reaction velocity; up to a point (at p-NO2), decrease of electron availability in the side chain decreases the velocity, but greater electron recession (in 2,4-(NO2)2) from the side chain to the nucleus reverses this effect and greatly increases the velocity. 2,4-Dinitrobenzylpyridinium bromide, m. 196° (decomposition). p-Ethylbenzyl bromide, b0.8 84°, m. 14.5-5.2°, from the chloride and NaBr in 90% aqueous Me2CO; iso-Pr homolog, b0.4 75°; tert-Bu homolog, b0.3 99°, m. 15.1°; 2,4-dimethylbenzyl bromide, b1.2 79°, m. 15°.

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SDS of cas: 114834-02-5. The protonation of heteroatoms in aromatic heterocycles can be divided into two categories: lone pairs of electrons are in the aromatic ring conjugated system; and lone pairs of electrons do not participate. Compound: 4-Chloro-6-(1H-imidazol-1-yl)pyrimidine, is researched, Molecular C7H5ClN4, CAS is 114834-02-5, about An electrochemical synthesis of functionalized arylpyrimidines from 4-amino-6-chloropyrimidines and aryl halides. Author is Sengmany, Stephane; Le Gall, Erwan; Leonel, Eric.

A range of novel 4-amino-6-arylpyrimidines was prepared under mild conditions by an electrochem. reductive cross-coupling between 4-amino-6-chloro-pyrimidines and functionalized aryl halides. The process, which employed a sacrificial iron anode in conjunction with a nickel(II) catalyst, allows the formation of coupling products in moderate to high yields.

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Formula: C3H12Cl2N2. Aromatic heterocyclic compounds can also be classified according to the number of heteroatoms contained in the heterocycle: single heteroatom, two heteroatoms, three heteroatoms and four heteroatoms. Compound: (S)-Propane-1,2-diamine dihydrochloride, is researched, Molecular C3H12Cl2N2, CAS is 19777-66-3, about Topography of nucleic acid helices in solutions. IX. Models for the interactions of optically active diamines, amino acid amides, diamino acids, and lysyl dipeptides with nucleic acid systems. Author is Gabbay, Edmond J..

Mol. framework models of the complexes formed between the salts N+H3CHRCONHCH2CH2N+Me2N.2Br- (I), N+H3C(CO2-)H(CH2)nH+H3Cl- (n = 2, 3, and 4) (II), N+HEC[CH2]4N+H3]HCONHCHRCO2-Cl-, (III), and N+H3CHRCH2N+H3.2Cl- (R = Me and CO2H) (IV) and adjacent phosphate anions of a helical polynucleotide chain were examined in detail; 15-, 16-, 17-, and 18-membered rings are formed as the result of complexing the salts I-IV to the nucleic acid helix. Certain conformations are not as favorable as other. Moreover, it is possible to predict which of the two optical isomers of I-IV should interact to a greater extent with a nucleic acid helix. The results using 11 different sets of optical isomers of I-IV on three different helical structures, i.e., poly I-poly C, poly A-poly U, and calf thymus DNA, were predicted correctly and consistently.

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So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic.Ding, Yong; Zhao, Wei researched the compound: 8-Hydroxyquinoline 1-oxide( cas:1127-45-3 ).Computed Properties of C9H7NO2.They published the article 《The oxidation of pyridine and alcohol using the Keggin-type lacunary polytungstophosphate as a temperature-controlled phase transfer catalyst》 about this compound( cas:1127-45-3 ) in Journal of Molecular Catalysis A: Chemical. Keywords: pyridine oxide preparation; oxidation pyridine polytungstophosphate catalyst; ketone preparation; alc oxidation polytungstophosphate catalyst. We’ll tell you more about this compound (cas:1127-45-3).

A novel temperature-controlled phase transfer catalyst of [(C18H37)2(CH3)2N]7[PW11O39] has been developed for the oxidation of pyridines and alcs. with hydrogen peroxide. The reactions were conducted in 1,4-dioxane, and high yields of the corresponding heterocyclic N-oxides and ketones were obtained under relative mild conditions. The catalyst could be easily recovered and reused after reaction with cooling. There was no discernable loss in activity and selectivity after several reaction cycles.

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Application In Synthesis of (R)-2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine. Aromatic heterocyclic compounds can also be classified according to the number of heteroatoms contained in the heterocycle: single heteroatom, two heteroatoms, three heteroatoms and four heteroatoms. Compound: (R)-2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine, is researched, Molecular C38H34N2O4P2, CAS is 221012-82-4, about Nickel-Catalyzed Asymmetric α-Arylation and Heteroarylation of Ketones with Chloroarenes: Effect of Halide on Selectivity, Oxidation State, and Room-Temperature Reactions. Author is Ge, Shaozhong; Hartwig, John F..

We report the α-arylation of ketones with a range of aryl chlorides with enantioselectivities from 90 to 99% ee catalyzed by the combination of Ni(COD)2 and (R)-BINAP and the coupling of ketones with a range of heteroaryl chlorides with enantioselectivities up to 99% ee catalyzed by Ni(COD)2 and (R)-DIFLUORPHOS. The analogous reactions of bromoarenes occur with much lower enantioselectivities. Mechanistic studies showed that the difference in the rates of decomposition of the arylnickel(II) halide intermediates to {[(R)-BINAP]NiX}2 likely accounts for the difference in the enantioselectivities of the reactions of bromoarenes and chloroarenes. This catalyst decomposition can be overcome by conducting the reactions with [(R)-BINAP]Ni(η2-NC-Ph) (4), which undergoes oxidative addition to haloarenes at room temperature

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Application of 217192-22-8. The fused heterocycle is formed by combining a benzene ring with a single heterocycle, or two or more single heterocycles. Compound: (4-(Pyridin-4-yl)phenyl)methanol, is researched, Molecular C12H11NO, CAS is 217192-22-8, about Identification of a Selective, Non-Prostanoid EP2 Receptor Agonist for the Treatment of Glaucoma: Omidenepag and its Prodrug Omidenepag Isopropyl. Author is Iwamura, Ryo; Tanaka, Masayuki; Okanari, Eiji; Kirihara, Tomoko; Odani-Kawabata, Noriko; Shams, Naveed; Yoneda, Kenji.

EP2 receptor agonists are expected to be effective ocular hypotensive agents; however, it has been suggested that agonism to other EP receptor subtypes may lead to undesirable effects. Through medicinal chem. efforts, we identified a scaffold bearing a (pyridin-2-ylamino)acetic acid moiety as a promising EP2-selective receptor agonist. (6-((4-(Pyrazol-1-yl)benzyl)(pyridin-3-ylsulfonyl)aminomethyl)pyridin-2-ylamino)acetic acid 13ax (omidenepag, OMD) exerted potent and selective activity toward the human EP2 receptor (h-EP2). Low doses of omidenepag iso-Pr (OMDI), a prodrug of 13ax, lowered intraocular pressure (IOP) in ocular normotensive monkeys. OMDI was selected as a clin. candidate for the treatment of glaucoma.

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Epoxy compounds usually have stronger nucleophilic ability, because the alkyl group on the oxygen atom makes the bond angle smaller, which makes the lone pair of electrons react more dissimilarly with the electron-deficient system. Compound: (S)-Propane-1,2-diamine dihydrochloride, is researched, Molecular C3H12Cl2N2, CAS is 19777-66-3, about Cold Crystallization of Chiral Schiff-Base Nickel(II) Complex Having Alkyl Chains and a Characteristic Methyl Group.Related Products of 19777-66-3.

Mols. exhibiting cold crystallization, an exothermic phenomenon in heating following supercooling, can be used as a heat storing material. However, examples in nonpolymers are still few. A chiral Schiff-base nickel(II) complex, which had a characteristic Me group and long alkyl chains, exhibited complicated thermal behavior including cold crystallization The Me group was a steric barrier to dimerization and mol. stacking, leading to the supercooled state. The thermal behavior of enantiomer was different from that of racemate.

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Category: quinoxaline. So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic. Compound: 1-(Bromomethyl)-4-ethylbenzene, is researched, Molecular C9H11Br, CAS is 57825-30-6, about Synthesis of novel blue light emitting 9,9′-bianthracene derivatives and their optoelectronic properties.

A series of novel blue light emitting materials 9,9′-bianthracene derivatives have been designed and synthesized by introducing different substituent groups through Suzuki coupling reactions. Their structure was identified by H NMR and UV-Vis absorption and fluorescence emission; Moreover, their fluorescence quantum efficiency and electrochem. properties were characterized in detail. The results indicate that all these compounds emit blue light, compared with 9,9′-bianthracene, the maximum emission peak of these materials is at 453 nm, red shift of 7 nm, and it is the typical blue fluorescence. This is because these derivatives have a non planar geometric structure. These derivatives also present high fluorescence quantum efficiency and are 1.18-1.43 times as much as that of 9,9′-bianthracene. In addition, their redox actives are also improved. Consequently, it was believed that these derivatives are potential ideal blue light fluorescent materials.

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The chemical properties of alicyclic heterocycles are similar to those of the corresponding chain compounds. Compound: (R)-2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine, is researched, Molecular C38H34N2O4P2, CAS is 221012-82-4, about Multicomponent Cyclopropane Synthesis Enabled by Cu-Catalyzed Cyclopropene Carbometalation with Organoboron Reagent: Enantioselective Modular Access to Polysubstituted 2-Arylcyclopropylamines, the main research direction is enantioselective multicomponent synthesis arylcyclopropylamine; copper catalyzed cyclopropene carbometalation organoboron reagent.Reference of (R)-2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine.

The use of functional-group-tolerant organoboron in lieu of basic organometallic reagents in base-metal-catalyzed cyclopropene carbometalation opens three-component cyclopropane synthesis, as exemplified by the modular assembly of the highly medicinally relevant 2-arylcyclopropylamine (ACPA) framework via stereoselective carboamination. The highly enantioselective version has been realized to afford enantioenriched ACPAs with up to all three cyclopropyl carbons as stereogenic centers in one operation, representing the first example of enantioselective multicomponent cyclopropane synthesis. The reaction significantly improves the efficiency of ACPA synthesis and may inspire the development of other multicomponent cyclopropane syntheses beyond amination.

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The preparation of ester heterocycles mostly uses heteroatoms as nucleophilic sites, which are achieved by intramolecular substitution or addition reactions. Compound: (R)-2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine( cas:221012-82-4 ) is researched.Quality Control of (R)-2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine.Suzuki, Shunsuke; Shibata, Yu; Tanaka, Ken published the article 《Rhodium-Catalyzed Asymmetric [2+2+2] Cycloaddition of 1,6-Enynes with Racemic Secondary Allylic Alcohols through Kinetic Resolution》 about this compound( cas:221012-82-4 ) in Chemistry – A European Journal. Keywords: bicyclic cyclohexene preparation enantioselective diastereoselective; enyne allylic alc cycloaddition reaction rhodium catalyst; allylic alcohols; asymmetric [2+2+2] cycloaddition; enynes; kinetic resolution; rhodium. Let’s learn more about this compound (cas:221012-82-4).

It has been established that a cationic rhodium(I)/P-phos complex catalyzes the asym. [2+2+2] cycloaddition of 1,6-enynes R1CCCH2ZCH2CH(=CH2)R2 (R1 = Me, Ph, pentyl; R2 = H, Me) with racemic secondary allylic alcs. R3CH(OH)CH=CH2 to produce the corresponding chiral bicyclic cyclohexenes I, possessing three stereogenic centers, as a single diastereomer with excellent ee values. Mechanistic experiments revealed that the present cycloaddition proceeds through the kinetic resolution of the racemic secondary allylic alcs., in which one enantiomer preferentially reacts with the 1,6-enyne.

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