Day: February 9, 2023

A new bis-cyclometalated iridium (III) complex as a triplet emitter in organic light emitting devices was written by Das, Rupasree R.;Kwon, Ohyun;Byun, Younghun;Lyu, Yi-Yeol;Kim, Myeong Suk;Kim, Heekyung;Han, Eun Sil;Kim, Mu Gyum;Park, Jong-Jin;Pu, Lyong Sun. And the article was included in Materials Research Society Symposium Proceedings in 2005.Electric Literature of C6H9N3O This article mentions the following:

We report a new iridium(III) complex and the study of its optical, electrochem. and electroluminescence properties. The crystal structure shows an octahedral environment around Ir(III) center. OLED. D. functional theory (DFT) calculations indicate the contribution of the d-orbitals of Ir and the π-orbitals of the cyclometalating and ancillary ligands toward HOMO, whereas LUMO is concentrated on only the cyclometalating ligand. These complexes emit in the sky blue color region from an admixture of triplet metal-to-ligand-charge-transfer (³MLCT) and ligand π-π* states. A maximum external (η_ex) quantum efficiency and luminance efficiency of 2.4% and 5.5 cd/A at 0.12 mA/cm² was obtained from the device consisting of a 5% doped polymeric and low mol. host. A maximum brightness of 10,200 cd/m² at 14.8 V was obtained from the device. In the experiment, the researchers used many compounds, for example, 3,5-Dimethyl-1H-pyrazole-1-carboxamide (cas: 934-48-5Electric Literature of C6H9N3O).

3,5-Dimethyl-1H-pyrazole-1-carboxamide (cas: 934-48-5) belongs to pyrazole derivatives. The 1H-pyrazole provides an excellent means by which to provide the requisite hydrogen bond acceptor–donor motifs, whether as a monocyclic ring or as a fused indazole ring. Pyrazoles are commonly used scaffold molecules in drug discovery projects. The use of pyrazole derivatives is based on their analgesic, anti-inflammatory, antipyretic, antiarrhythmic, sedative, muscle relaxant, neuroleptic, anticonvulsant, monoamine oxidase inhibitory, antidiabetic and antibacterial activities.Electric Literature of C6H9N3O

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyridine-pyrazole compound as inhibitor for steel in 1M HCl was written by Bouklah, M.;Attayibat, A.;Hammouti, B.;Ramdani, A.;Radi, S.;Benkaddour, M.. And the article was included in Applied Surface Science in 2005.Application In Synthesis of 2-(5-Methyl-1H-pyrazol-3-yl)pyridine This article mentions the following:

The influence of 3,5-dimethyl-1H-pyrazole, pyridine and 2-(3-methyl-1H-pyrazol-5-yl) pyridine (P3) on the corrosion inhibition of carbon steel in 1M HCl solution was studied by using weight-loss, potentiodynamic and EIS measurements. P3 was the best inhibitor, and its inhibition efficiency increases with increasing inhibitor concentration to attain 89% at 10^-3 M. Potentiodynamic polarization studies clearly reveal that it acts essentially as a cathodic inhibitor. The inhibitor decreased the corrosion rates. The efficiency values obtained by the various methods used were in agreement. Adsorption of P3 on the steel surface has an S-shaped adsorption isotherm. In the experiment, the researchers used many compounds, for example, 2-(5-Methyl-1H-pyrazol-3-yl)pyridine (cas: 19959-77-4Application In Synthesis of 2-(5-Methyl-1H-pyrazol-3-yl)pyridine).

2-(5-Methyl-1H-pyrazol-3-yl)pyridine (cas: 19959-77-4) belongs to pyrazole derivatives. Pyrazole has two ring nitrogen atoms in which N1 is pyrrolic and N2 is pyridine-like. The N1 nitrogen is not reactive but is deprotonated in the presence of a base-forming anion. Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns.Application In Synthesis of 2-(5-Methyl-1H-pyrazol-3-yl)pyridine

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Analysis of volatile constituents of Baimaohou (Camellia sinensis L.) by gas chromatography-mass spectrum was written by Zhuang, Wuyoung;Cai, Jibao;Su, Qingde. And the article was included in Asian Journal of Chemistry in 2005.Application of 3528-58-3 This article mentions the following:

Volatile oil of Baimaohou (Camellia sinensis L.) was obtained by simultaneous distillation-solvent extraction Following, the essential oil was analyzed by gas chromatog.-mass spectrum. 48 Components at least were identified, constituting approx. 74% of the oil. The main constituents of the essential oil were phytol (16.4%) and 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-2(4H)-benzofuranone (10.6%), a very expensive flavor material. In the experiment, the researchers used many compounds, for example, 1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3Application of 3528-58-3).

1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3) belongs to pyrazole derivatives. Pyrazole has two ring nitrogen atoms in which N1 is pyrrolic and N2 is pyridine-like. The N1 nitrogen is not reactive but is deprotonated in the presence of a base-forming anion. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.Application of 3528-58-3

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Enhanced Catalytic Activity of Aluminum Complexes for the Ring-Opening Polymerization of ε-Caprolactone was written by Kosuru, Someswara Rao;Sun, Ting-Han;Wang, Li-Fang;Vandavasi, Jaya Kishore;Lu, Wei-Yi;Lai, Yi-Chun;Hsu, Sodio C. N.;Chiang, Michael Y.;Chen, Hsuan-Ying. And the article was included in Inorganic Chemistry in 2017.SDS of cas: 15953-73-8 This article mentions the following:

A series of dinuclear aluminum (Al₂Pyr₂) complexes bridged by two ligands were synthesized, and their catalytic activity toward ring-opening polymerization of ε-caprolactone (CL) was investigated. Different types of the Al-N-N-Al-N-N skeletal ring were found among these Al₂Pyr₂ complexes. The butterfly form, L^Thio₂Al₂Me₄, exerted the highest catalytic activity for CL polymerization κ²-2-CL coordination with both Al centers within the butterly form L^Thio₂Al₂Me₄ facilitates the initiation process. Generally speaking, the Al₂Pyr₂ complexes exhibited substantially higher catalytic activity for CL polymerization than literature examples such as β-diketiminate- or traiaza-bearing aluminum complexes. In fact, the Al₂Pyr₂ complexes can even carry out CL polymerization at 25°. In the experiment, the researchers used many compounds, for example, 4-Chloro-3,5-dimethyl-1H-pyrazole (cas: 15953-73-8SDS of cas: 15953-73-8).

4-Chloro-3,5-dimethyl-1H-pyrazole (cas: 15953-73-8) belongs to pyrazole derivatives. As is the case with imidazoles, the pyrazole ring offers many opportunities to create new multiring systems that incorporate this heterocycle. Pyrazoles and pyrimidines have diverse biological and pharmacological activities. There are a number of antimicrobial compounds containing pyrazole moiety as the core unit. Pyrazofurin is important antimicrobial drug and 2-methylpyrimidine-4-ylamine derivatives I and II were found to be effective inhibitors of Escherichia coli PDHc-E1 with antibacterial and antifungal activity.SDS of cas: 15953-73-8

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Novel η³-Allylpalladium-Pyridinylpyrazole Complex: Synthesis, Reactivity, and Catalytic Activity for Cyclopropanation of Ketene Silyl Acetal with Allylic Acetates was written by Satake, Akiharu;Nakata, Tadashi. And the article was included in Journal of the American Chemical Society in 1998.Application of 19959-77-4 This article mentions the following:

Novel cationic η³-allylpalladium-pyridinylpyrazole complexes I (R = Me, Bu^t) were synthesized from 3-alkyl-5-(2-pyridinyl)pyrazole and η³-allylpalladium chloride dimer in the presence of AgBF₄. Cationic complexes I were converted into neutral complexes II under basic conditions. These complexes were characterized by ¹H, ¹³C, and ¹⁵N NMR studies. Neutral complexes II have high catalytic activity for cyclopropanation of ketene silyl acetals with allylic acetates. Comparison of the cationic and neutral complexes and the reaction mechanism of cyclopropanation were discussed. In the experiment, the researchers used many compounds, for example, 2-(5-Methyl-1H-pyrazol-3-yl)pyridine (cas: 19959-77-4Application of 19959-77-4).

2-(5-Methyl-1H-pyrazol-3-yl)pyridine (cas: 19959-77-4) belongs to pyrazole derivatives. Pyrazole has two ring nitrogen atoms in which N1 is pyrrolic and N2 is pyridine-like. The N1 nitrogen is not reactive but is deprotonated in the presence of a base-forming anion. The pyrazole ring is resistant to oxidation and reduction but the groups, such as alkyl and formyl attached to the ring, are oxidized to respective acids. Only electrolytic oxidation, ozonolysis, and a strong base cause ring opening.Application of 19959-77-4

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Oxidation of pyrazolinones was written by Bischoff, Christian;Ramm, Matthias;Schroeder, Edith;Jancke, Harald. And the article was included in Journal fuer Praktische Chemie/Chemiker-Zeitung in 1994.Computed Properties of C4H5BrN2O This article mentions the following:

Oxidation of pyrazolinones I (R = H, Ph, CONH₂) with H₂O₂/HCOOH gave dimer II which underwent cleavage on treatment with either phenylhydrazine or Br₂ to pyrazolinones III (Q = :NNHPh, Br, resp.). In the experiment, the researchers used many compounds, for example, 4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9Computed Properties of C4H5BrN2O).

4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9) belongs to pyrazole derivatives. An alternative way to synthesize multisubstituted pyrazoles is the Csingle bondH arylation of simple pyrazoles. The pyrazole ring is resistant to oxidation and reduction but the groups, such as alkyl and formyl attached to the ring, are oxidized to respective acids. Only electrolytic oxidation, ozonolysis, and a strong base cause ring opening.Computed Properties of C4H5BrN2O

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

CO₂ Hydrogenation and Formic Acid Dehydrogenation Using Ir Catalysts with Amide-Based Ligands was written by Kanega, Ryoichi;Ertem, Mehmed Z.;Onishi, Naoya;Szalda, David J.;Fujita, Etsuko;Himeda, Yuichiro. And the article was included in Organometallics in 2020.Formula: C6H9N3O This article mentions the following:

A series of Ir catalysts [Cp*Ir(H₂O)(QCXNHR)][SO₄] (1–16; Q = 2-pyridyl, 4-hydroxy-2-pyridyl, 6-hydroxy-2-pyridyl, 2-imidazolyl, 1-pyrazolyl; X = O, S, NH; R = H, Me, Ph, 4-hydroxyphenyl) bearing amide-based ligands were isolated or generated in situ by a deprotonated amide moiety with the hypotheses that strong electron-donating ability of the coordinated anionic nitrogen atom and the proton-responsive OH group near the metal center will improve the catalytic activity for CO₂ hydrogenation and formic acid (FA) dehydrogenation. The effects of the modifications of the ligand architecture on the catalytic activity were investigated for CO₂ hydrogenation at ambient conditions (25° with 0.1 MPa H₂/CO₂ (volume/volume = 1/1)) and under slightly harsher conditions (50° with 1.0 MPa H₂/CO₂) in basic aqueous solutions together with deuterium kinetic isotope effects (KIEs) with selected catalysts. Complex [Cp*Ir(L12)(H₂O)][HSO₄] (12, L12 = 6-hydroxy-N-phenylpicolinamidate) that has an anionic coordinating N atom and an OH group in the second coordination sphere, exhibits a TOF of 198 h^-1 based on the initial 1 h of reaction. This TOF which, to the best of our knowledge, is the highest value ever reported under ambient conditions in basic aqueous solutions However, complex [Cp*Ir(L10)(H₂O)][HSO₄] (L10 = 4-hydroxy-N-methylpicolinamidate) performs better in long-term CO₂ hydrogenation (up to a TON of 14700 with [Ir] = 10μM after 348 h and the final formate concentration of 0.643 M with [Ir] = 250μM.) at ambient conditions. Further, the catalytic activity for FA dehydrogenation was examined under three different conditions (pH 1.6, 2.3 and 3.5). The complex 12 in any of these conditions is less active compared to the picolinamidate catalysts without ortho-OH, owing to its instability. Theor. calculations were performed to examine the catalytic mechanism, and a step-by-step mechanism has been proposed for both CO₂ hydrogenation and FA dehydrogenation reactions. D. functional theory calculations of [Cp*Ir(L3)(H₂O)][HSO₄] (L3 = picolinamidate) and the X-ray structure of the [Cp*Ir(L7)(H)]•H₂O (L7 = N-methylpicolinamidate) complex imply a pH-dependent conformational change from N,N coordination to N,O coordination upon lowering the pH of the aqueous solution In the experiment, the researchers used many compounds, for example, 3,5-Dimethyl-1H-pyrazole-1-carboxamide (cas: 934-48-5Formula: C6H9N3O).

3,5-Dimethyl-1H-pyrazole-1-carboxamide (cas: 934-48-5) belongs to pyrazole derivatives. An alternative way to synthesize multisubstituted pyrazoles is the Csingle bondH arylation of simple pyrazoles. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.Formula: C6H9N3O

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Features of reactions of (E)-1-(β-aroylvinyl)pyridinium bromides with binucleophiles was written by Khachikyan, R. Dzh.;Ovakimyan, Z. G.;Panosyan, G. A.;Tamazyan, R. A.;Ayvazyan, A. G.. And the article was included in Russian Journal of General Chemistry in 2016.Category: pyrazoles-derivatives This article mentions the following:

Reactions of (E)-1-(β-aroylvinyl)pyridinium bromides with hydrazine led to the formation of pyrazole derivatives I•HCl (R = Me, Cl, Br) regardless of pH and a solvent nature. The salts reacted with thiourea via intermediate formation of 4-arylpyrimidine-2-thiol to gave (Z)-2-[(β-aroylvinyl)sulfanyl]-4 arylpyrimidines II (R = Me, Cl, Br). In the case of N,N’-diphenylthiourea the reaction provided 6-aryl-3-aroyl-1-phenylpyridinium bromides III•Br^– (R = Me, Cl, Br). Pyridine hydrobromide liberated in the reaction course had a major influence on the process chemoselectivity. In the experiment, the researchers used many compounds, for example, 3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9Category: pyrazoles-derivatives).

3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9) belongs to pyrazole derivatives. The 1H-pyrazole provides an excellent means by which to provide the requisite hydrogen bond acceptor–donor motifs, whether as a monocyclic ring or as a fused indazole ring. Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns.Category: pyrazoles-derivatives

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Pyrazolo-pyrimidines: A novel heterocyclic scaffold for potent and selective p38α inhibitors was written by Das, Jagabandhu;Moquin, Robert V.;Pitt, Sidney;Zhang, Rosemary;Shen, Ding Ren;McIntyre, Kim W.;Gillooly, Kathleen;Doweyko, Arthur M.;Sack, John S.;Zhang, Hongjian;Kiefer, Susan E.;Kish, Kevin;McKinnon, Murray;Barrish, Joel C.;Dodd, John H.;Schieven, Gary L.;Leftheris, Katerina. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2008.Recommanded Product: 1-Ethyl-1H-pyrazol-3-amine This article mentions the following:

The synthesis and structure-activity relationships (SAR) of p38α MAP kinase inhibitors based on a pyrazolo-pyrimidine scaffold are described. These studies led to the identification of compound I as a potent and selective inhibitor of p38α MAP kinase with excellent cellular potency toward the inhibition of TNFα production I was highly efficacious in vivo in inhibiting TNFα production in an acute murine model of TNFα production X-ray co-crystallog. of a pyrazolopyrimidine analog bound to unphosphorylated p38α is also disclosed. In the experiment, the researchers used many compounds, for example, 1-Ethyl-1H-pyrazol-3-amine (cas: 55361-49-4Recommanded Product: 1-Ethyl-1H-pyrazol-3-amine).

1-Ethyl-1H-pyrazol-3-amine (cas: 55361-49-4) belongs to pyrazole derivatives. The strategies for the synthesis of pyrazoles generally can be applied for the construction of indazoles. The presence of both electronegative nitrogen atoms in the pyrazole ring reduces the electron density of the C3- and C5-positions leaving electron density of C4-position unaltered. Thus the C4-position is vulnerable to electrophilic attack. The C3 electrophilic-position may undergo deprotonation in the presence of a strong base leading to ring opening.Recommanded Product: 1-Ethyl-1H-pyrazol-3-amine

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

The substituent effects on the chemical shifts of aromatic protons in heterocyclic compounds was written by Liang, Desheng;Lai, Zhugen;Xu, Guanzhi;Jiang, Mingqian. And the article was included in Huaxue Xuebao in 1982.Category: pyrazoles-derivatives This article mentions the following:

The substituent effect on the chem. shifts in ³H NMR of aromatic heterocycles (e.g., furan, thiophene) depended on the electronic effect and the position of the substituents. An empirical formula was derived and the chem. shifts of >700 aromatic protons were calculated to show a deviation of ±0.2-0.3 ppm. In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4Category: pyrazoles-derivatives).

3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4) belongs to pyrazole derivatives. Pyrazoles, a five-membered heterocycle containing two adjacent nitrogen atoms, are the core structures found in a number of molecules that possess a wide range of pharmaceutical and agricultural activities. Pyrazoles and pyrimidines have diverse biological and pharmacological activities. There are a number of antimicrobial compounds containing pyrazole moiety as the core unit. Pyrazofurin is important antimicrobial drug and 2-methylpyrimidine-4-ylamine derivatives I and II were found to be effective inhibitors of Escherichia coli PDHc-E1 with antibacterial and antifungal activity.Category: pyrazoles-derivatives

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics