pyrazoles-derivatives

Evidence for the in Vitro Bioactivation of Aminopyrazole Derivatives: Trapping Reactive Aminopyrazole Intermediates Using Glutathione Ethyl Ester in Human Liver Microsomes was written by Ryan, Eileen;Morrow, Benjamin J.;Hemley, Catherine F.;Pinson, Jo-Anne;Charman, Susan A.;Chiu, Francis C. K.;Foitzik, Richard C.. And the article was included in Chemical Research in Toxicology in 2015.Category: pyrazoles-derivatives This article mentions the following:

Drug-induced toxicity is a leading cause of drug withdrawal from clin. development and clin. use and represents a major impediment to the development of new drugs. The mechanisms underlying drug-induced toxicities are varied; however, metabolic bioactivation to form reactive metabolites has been identified as a major contributor. These electrophilic species can covalently modify important biol. macromols. and thereby increase the risk of adverse drug reactions or idiosyncratic toxicity. Consequently, screening compounds for their propensity to form reactive metabolites has become an integral part of drug discovery programs. This screening process typically involves identification of structural alerts as well as the generation of reactive metabolites in vitro in subcellular hepatic fractions, followed by trapping the reactive species with nucleophiles and characterization via LC-MS. This article presents evidence for the bioactivation of a series of aminopyrazole derivatives via LC-MS detection of glutathione Et ester-trapped reactive intermediates formed in human liver microsomal incubations. These results indicate that the aminopyrazole motif, within specific contexts, may be considered a new structural alert for the potential formation of reactive metabolites. 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. 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.Category: pyrazoles-derivatives

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

Antitumor activity of eighty-four synthesized N-heteroaromatic compounds was written by Hayashi, Eisaku;Higashino, Takeo;Iijima, Chihoko;Oishi, Etsuo;Makino, Hirokazu;Irie, Toshio;Yamamoto, Fusako;Yokoyama, Yoko;Iwai, Yoshihisa. And the article was included in Yakugaku Zasshi in 1977.Product Details of 18213-75-7 This article mentions the following:

Eighty-four compounds (mainly N-heteroaromatic compounds) were synthesized and their antitumor activity was examined Four quinoline derivatives had some antitumor effect on the solid type of Ehrlich carcinoma. These compounds were, 3-hydroxy-6-quinolinecarbonitrile (I) [63124-12-9], 6-bromoquinaldic acid 1-oxide [65147-79-7], 8-(hydroxyimino)-5,6,7,8-tetrahydroquinoline [58509-59-4] and 1-(hydroxyimino)-1,2,3,4-tetrahydroacridine [34043-68-0]. No other derivatives were found effective. In the experiment, the researchers used many compounds, for example, 5-Amino-1-methyl-1H-pyrazole-4-carboxamide (cas: 18213-75-7Product Details of 18213-75-7).

5-Amino-1-methyl-1H-pyrazole-4-carboxamide (cas: 18213-75-7) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 鎺矯).Pyrazole used as a ligand to prepare organometallic compounds. Pyrazole rings have been used as core components of several leading non-steroidal anti-inflammatory drugs (NSAIDs) and antihypertensive drugs. It has also been found to be useful as a bifunctional ligand for metal catalysis.Product Details of 18213-75-7

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

Method for preparation of C-(diformylmethyl)nitropyrazoles was written by Dalinger, I. L.;Shkineva, T. K.;Shevelev, S. A.;Kral, V.;Arnold, Z.;Kanishchev, M. I.. And the article was included in Izvestiya Akademii Nauk, Seriya Khimicheskaya in 1993.Formula: C4H5N3O2 This article mentions the following:

Pyrazoletrimethinium salts have been synthesized by double formylation of the corresponding C-methylnitropyrazoles. Trimethinium hydrolysis of the trimethinium salts leads to C-(diformylmethyl)nitropyrazoles, e.g., I. In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4Formula: C4H5N3O2).

3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 鎺矯).Pyrazole used as a ligand to prepare organometallic compounds. 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: C4H5N3O2

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

Organic reactions in aqueous solution at room temperature. II. Influence of pH on condensations involving the linkage of carbon to carbon, of carbon to nitrogen, and of carbon to sulfur was written by Bethell, J. R.;Maitland, P.. And the article was included in Journal of the Chemical Society in 1961.Category: pyrazoles-derivatives This article mentions the following:

Further simple reactions under “physiological” (“cell-possible”) conditions were described, leading to the formation of the C₆H₆, the pyrazole, and the thiazole ring system. Two examples of the Michael reaction under mild conditions were given. The general exptl. conditions adopted were those described in the previous paper. The work was described in four sections. (a) Double C-C Claisen-Knoevenagel condensation of two C-3 aliphatic units to give a benzene derivative Diethyl 2-hydroxy-4,6-dimethylisophthalate (I) was prepared by condensing acetylacetone with diethyl acetonedicarboxylate. The reaction was carried out in a saturated buffered aqueous solution The results showed that I was formed in the pH range 5.6-9.2, the highest yield (86%) of pure product being precipitated at pH 7.3-7.6. This condensation could therefore proceed by the acid- or base-catalyzed mechanisms, and the fact that it took place within the physiol. pH range supported the possible origin of some natural benzene derivatives by a C-3 C-3 route of this type. (b) The Michael reaction (cyanoethylation). C-C condensation of Me acetoacetate (II) and vinyl cyanide (III) and C-N condensation of PhNH₂ and III. The influence of pH on two examples of cyanoethylation was studied. (1) II and III. II (2.32 g.) in buffer solution with 2.12 g. III in 40 ml. buffer solution left 6 days at room temperature gave varying yields of diethyl 浼?浼?bis(2-cyanoethyl)acetoacetate (IV), m. 154-6鎺? The maximum yield of IV was 46% at pH 10.7 and fell to 9.7. There was no trace of the monocyanoethylated product. No product was obtained in acid solution, which showed that this Michael type reaction could only proceed by the base-catalyzed mechanism. (2) PhNH₂ and III. III (1.06 g.) in 50 ml. buffer solution and 1.86 g. PhNH₂ in 150 ml. buffer solution left 20 days at room temperature gave N-(2-cyanoethyl)aniline (V), m. 50-1鎺? at varying pH values. The results showed that pure V was precipitated over the pH range 5.1-11.6 with a maximum yield of 44-5% at pH 7.5-10, except around pH 9.2 where there was a repeatable but unaccountable decrease of 5-6%. Although the duration of the actual experiment was 20 days, equimolar amounts of PhNH₂ and III in the buffer solution at pH 8.8 gave a 29% yield after 7 days; using double the amount of III under the same conditions gave 59% V. (c) C-N condensation to give a pyrazole derivative Semicarbazide-HCl (2.2 g.) and 2 g. acetylacetone in 70 cc. buffer solution gave 3,5-dimethylpyrazole-1-carboxamide (VI), m. 111-13鎺? under a variety of pH values. The results showed that the highest yield of VI, 86%, was precipitated at pH 4.1 and diminished to 17% at pH 8.2 and nil at pH 10. The duration of the experiments to obtain the maximum yield at each pH varied from 2 hrs. to 12 days. Below pH 4, hydrolysis and decarboxylation to 3,5-dimethylpyrazole was observed. (d) Combination of C-S and C-N condensations to give a thiazole derivative When buffer solutions of 0.625 g. N-ethylmaleimide and 0.38 g. CS(NH₂)₂ were left 2 days at room temperature, N-ethyl-浼?(2-imino-4-oxothiazolidin-5-yl)acetamide (VII) was obtained, m. 210-12鎺? The highest yield of VII, 74%, was obtained at pH 5.6. The rapid decline in the yield of VII on the alk. side was probably due to its hydrolysis. It was difficult to find a satisfactory mechanism for the formation of VII. It was formed, not only in aqueous alc., in aqueous buffers, but also in absolute alc. Two reactions would seem to be necessary: addition of the thiol form of thiourea across the double bond of the maleimide followed by nucleophilic attack by the more basic thiourea amino group on the adjacent carbonyl group, with subsequent proton shift. In the experiment, the researchers used many compounds, for example, 3,5-Dimethyl-1H-pyrazole-1-carboxamide (cas: 934-48-5Category: pyrazoles-derivatives).

3,5-Dimethyl-1H-pyrazole-1-carboxamide (cas: 934-48-5) 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. 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.Category: pyrazoles-derivatives

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

Mass spectrometry of nitroazoles. 4. Ortho effects: the loss of CHO閳?and formaldehyde from methyl-substituted nitrodiazoles was written by Luijten, W. C. M. M.;Van Thuijl, J.. And the article was included in Organic Mass Spectrometry in 1982.Recommanded Product: 5334-39-4 This article mentions the following:

The interaction between Me and NO₂ groups in some Me-substituted nitropyrazoles and -imidazoles caused the expulsion of CHO閳?and HCHO during electron-impact mass spectroscopy. This occurred when the 2 substituents were adjacent. Labeling with D and ¹³C showed that the loss of CHO閳?and HCHO originates exclusively from the substituents. The isotope effects observed in partially deuterated 3(5)-methyl-4-nitropyrazole were consistent with H transfer prior to fragmentation. In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4Recommanded Product: 5334-39-4).

3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4) belongs to pyrazole derivatives. The 1H-pyrazole provides an excellent means by which to provide the requisite hydrogen bond acceptor閳ユ徆onor motifs, whether as a monocyclic ring or as a fused indazole ring. 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: 5334-39-4

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

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