pyrazoles-derivatives

The N-alkylation and N-arylation of unsymmetrical pyrazoles was written by Grimmett, M. Ross;Lim, K. H. Richard;Weavers, Rex T.. And the article was included in Australian Journal of Chemistry in 1979.Name: 3-(4-Bromophenyl)-1H-pyrazole This article mentions the following:

Unsym. pyrazoles with alkyl, aryl, nitro and carboxyl substituents at C-3 or C-5 were methylated with Me₂SO₄-MeOH, Me₂SO₂ in basic medium, and with CH₂N₂. The ratios of the isomeric N-methylpyrazoles were determined by NMR and gas liquid chromatog. The modified Ullmann phenylation was also applied to these pyrazoles. Product orientations involve considerations of electronic and steric effects, the possible intermediacy of quaternary salts, and the likelihood that the dominant tautomer is reacting. In the experiment, the researchers used many compounds, for example, 3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9Name: 3-(4-Bromophenyl)-1H-pyrazole).

3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9) 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 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.Name: 3-(4-Bromophenyl)-1H-pyrazole

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

Effects of hydrogen bond on the melting point of azole explosives was written by Wang, Jian-Hua;Shen, Chen;Liu, Yu-Cun;Luo, Jin;Duan, Yingjie. And the article was included in Journal of Molecular Structure in 2018.Safety of 3-Methyl-4-nitro-1H-pyrazole This article mentions the following:

M.p. is an important index to determine whether an explosive can be a melt cast carrier. In this study, the relationship among the mol. structure, crystal structure, and m.p. of explosives was investigated by using nitroazole compounds Hydrogen bonds influence crystal packing modes in chem. understandable ways. Hydrogen bonds also affect the changes in entropy and enthalpy in balancing melting process. Hence, different types of hydrogen bonds in explosive crystal structures were compared when the relationship between the mol. structure and the m.p. of nitroazole explosives were analyzed. The effects of Me and amino groups on intermol. hydrogen bonds were also compared. Results revealed that the Me and amino groups connected on the N(1) of the heterocyclic compound can reduce the m.p. of azole explosive. This finding is possible because Me and amino groups destroy the intermol. hydrogen bond of the heterocyclic compound In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4Safety of 3-Methyl-4-nitro-1H-pyrazole).

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. Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns.Safety of 3-Methyl-4-nitro-1H-pyrazole

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

From N-H Nitration to Controllable Aromatic Mononitration and Dinitration-The Discovery of a Versatile and Powerful N-Nitropyrazole Nitrating Reagent was written by Yang, Tao;Li, Xiaoqian;Deng, Shuang;Qi, Xiaotian;Cong, Hengjiang;Cheng, Hong-Gang;Shi, Liangwei;Zhou, Qianghui;Zhuang, Lin. And the article was included in JACS Au in 2022.Formula: C4H5N3O2 This article mentions the following:

Herein,the identification of a powerful nitrating reagent, 5-methyl-1,3-dinitro-1H-pyrazole, from the N-nitro-type reagent library constructed using a practical N-H nitration method was reported. This nitrating reagent behaved as a controllable source of the nitronium ion, enabling mild and scalable nitration of a broad range of (hetero)arenes with good functional group tolerance. Of note, this nitration method was controlled by manipulating the reaction conditions to furnish mononitrated or dinitrated product selectively. The value of this method in medicinal chem. was well established by its efficient late-stage C-H nitration of complex biorelevant mols. D. functional theory (DFT) calculations and preliminary mechanistic studies reveal that the powerfulness and versatility of this nitrating reagent were due to the synergistic “nitro effect” and “methyl effect”. 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. 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. 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.Formula: C4H5N3O2

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

Experimental Testing of Quantum Mechanical Predictions of Mutagenicity: Aminopyrazoles was written by Leach, Andrew G.;McCoull, William;Bailey, Andrew;Barton, Peter;Mee, Christine;Rosevere, Eleanor. And the article was included in Chemical Research in Toxicology in 2013.Name: 1-Ethyl-1H-pyrazol-3-amine This article mentions the following:

A computational method for predicting the likelihood of aromatic amines being active in the Ames test for mutagenicity was trialed on a set of aminopyrazoles. A virtual array of compounds was generated from the available sets of hydrazines and α-cyanoaldehydes (or ketones) and quantum mech. calculations used to compute a probability of being active in the Ames test. The compounds selected for synthesis and testing were not based on the predictions and so spanned the range of predicted probabilities. The subsequently generated results of the Ames test were in good correspondence with the predictions and confirm this approach as a useful means of predicting likely mutagenic risk. In the experiment, the researchers used many compounds, for example, 1-Ethyl-1H-pyrazol-3-amine (cas: 55361-49-4Name: 1-Ethyl-1H-pyrazol-3-amine).

1-Ethyl-1H-pyrazol-3-amine (cas: 55361-49-4) belongs to pyrazole derivatives. Pyrazole is a weak base, with pKb 11.5 (pKa of the conjugated acid 2.49 at 25 °C).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.Name: 1-Ethyl-1H-pyrazol-3-amine

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

κ²-κ³ Isomerism in Rhodium(I) Tris(pyrazolyl)borate Complexes of the Type Tp^3R,4R,5RRh(LL) (LL = 2CO, COD, and NBD) and Their Dynamic Behavior in Solution. X-ray Crystal Structure of Tp^MeRh(NBD) was written by Bucher, Urs E.;Currao, Antonio;Nesper, Reinhard;Rueegger, Heinz;Venanzi, Luigi M.;Younger, Elizabeth. And the article was included in Inorganic Chemistry in 1995.Related Products of 15953-73-8 This article mentions the following:

Rh(I) complexes Tp^3R,4R,5RRh(LL) (LL = 2 CO, NBD (norbornadiene), COD (1,5-cyclooctadiene), 3R = 4R = 5R = H; 3R = Me, 4R = 5R = H; 3R = Me, Ph, CF₃, 4R = H, 5R = Me; 3R = Me, 4R = Me, Cl, 5R = Me; 3R = ⁱPr, 4R = Br, 5R = H) were synthesized and fully characterized. Isomeric forms of three types were identified in solution for these compounds: type A, square planar complexes in which the Rh(NN)₂B six-membered ring has a boat conformation, the 3rd pyrazolyl ring being free and occupying an equatorial position; type B, compounds with a coordination geometry and chelate ring as above, but having the 3rd pyrazolyl ring in an axial position, i.e., an arrangement which can easily form pentacoordinate complexes; type C, five-coordinate species which, however, on the NMR time scale, are in a fast exchange with those B. In the carbonyl complexes (LL = 2 CO), compounds C can be distinguished from the forms A and B by IR spectroscopy. The dynamic equilibrium between the corresponding isomeric structures, A, B, and C, are solvent-dependent and can be shifted completely toward the forms B and C by placing a Me substituent in the 5-position of each pyrazole. For compounds possessing COD as a co-ligand, the formation of square-planar complexes B, with κ²-bonded pyrazolylborates is preferred, as indicated by ¹⁰³Rh NMR spectroscopy, whereas both four- and five-coordinate species are present in compounds having NBD as a co-ligand, their relative contributions being dependent on the substituents on the pyrazolyl rings. The x-ray crystal structure of the compound Tp^MeRh(NBD) (space group P2₁/c, a 18.152(3), b 16.732(4), c 20.591(4) Å; β = 141.793(7); Z = 8; R = 0.0457, R_w = 0.0412 for 3904 observed reflections) shows that the tris(pyrazolyl)borate ligand is κ³-bonded and the Rh atom has a distorted trigonal bipyramidal structure (type C), the two olefinic double bonds being in an equatorial and the an axial position, resp. In the experiment, the researchers used many compounds, for example, 4-Chloro-3,5-dimethyl-1H-pyrazole (cas: 15953-73-8Related Products of 15953-73-8).

4-Chloro-3,5-dimethyl-1H-pyrazole (cas: 15953-73-8) belongs to pyrazole derivatives. Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. Pyrazoles can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns.Related Products of 15953-73-8

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

Screening of volatile organic pollutants in water of Almaty lake-settler by SPME-GC-MS was written by Alimzhanova, M. B.. And the article was included in Izvestiya Natsional’noi Akademii Nauk Respubliki Kazakhstan, Seriya Khimii i Tekhnologii in 2016.Quality Control of 3-Methyl-4-nitro-1H-pyrazole This article mentions the following:

Environmental problems of big cities are directly related to the high concentration of population, industry and transport in small areas, which are the cause of a large number of industrial and domestic emissions. These emissions may represent a different kind of chem. compounds: volatile,semi-volatile and toxic organic compounds, which can be merged with water and pollute it. As a result there are several so-called lake-settlers, where contaminated water is stored for further purification An annual monitoring of these lakes it is necessary carry out for to prevent the possibility of getting these compounds in drinking water and harm to the environment. The Environmental Protection Agency offered EPA 8270S method for determination volatile and semi-volatile compounds in the environmental objects by GC-MS. However, this technique is not economically profitable,since it requires the use of expensive reference materials for calibration curve and set retention times of all 210 compounds and organic solvents for extraction The aim of this work is to develop a new selective, informative and efficient green method for the detection of VOCs in water without using organic solvents for extraction and without require of use expensive standard samples. Method of solid phase microextraction and GC/MS with identification of peaks by Kovatc’s indexes is the most appropriate responding to all requests for the detection of VOCs in the environment. The green method will enable to determine VOCs in environmental objects. Results of work included the optimization of SPME parameters and calculation of retention times of n-alkanes. Using the retention times and retention indexes of n-alkanes the dependence was built, which allowed to calculate the retention times of 210 organic pollutants. Also this method was successfully applied for anal. of water from Almaty Lake-Settler “Sorbulak” and 68 main organic compounds were identified, including phenolic compounds,pesticides and polyaromatic hydrocarbons. In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4Quality Control of 3-Methyl-4-nitro-1H-pyrazole).

3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4) belongs to pyrazole derivatives. Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. 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.Quality Control of 3-Methyl-4-nitro-1H-pyrazole

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

Orientation of the alkylation reaction of pyrazoles under neutral conditions and in phase-transfer catalysis was written by Tarrago, Georges;Ramdani, Abdelkrim;Elguero, Jose;Espada, Modesta. And the article was included in Journal of Heterocyclic Chemistry in 1980.Application of 19959-77-4 This article mentions the following:

The N-butylation and N-benzylation of nine pyrazoles bearing different substituents in positions 3 and 5 have been studied in neutral and basic medium (phase transfer catalysis). The orientation of the reaction depends strongly on the method used when the position 3 (or 5) of the starting pyrazole bears a substituent with a lone pair in the ortho position (pyrazolyl or pyridyl). 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. 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. 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.Application of 19959-77-4

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

Solvatochromism of Heteroaromatic Compounds: XIX. Factors Affecting Quantitative Characteristics of Solvatochromism in Aprotic Inert Media was written by Turchaninov, V. K.;Vokin, A. I.;Aksamentova, T. N.;Krivoruchka, I. G.;Shulunova, A. M.;Andriyankova, L. V.. And the article was included in Russian Journal of General Chemistry (Translation of Zhurnal Obshchei Khimii) in 2003.COA of Formula: C4H5N3O2 This article mentions the following:

The effects of aprotic inert media on the electronic absorption spectra of aromatic nitro compounds p-NO₂C₆H₄R were used as evidence for the linear correlation between the slope s_a of the solvatochromism equations ν_max = ν₀ + s_aπ^* and the dipole moments of the mols. in their ground electronic state μ_g. A linear correlation was established between ν₀ and the first ionization potential of subunits PhR. A new approach to estimating the dipole moment of electronically excited mols. (μ_e) for mols. like p-NO₂C₆H₄R from the correlation μ_e = rμ_g was proposed. In the experiment, the researchers used many compounds, for example, 1-Methyl-3-nitro-1H-pyrazole (cas: 54210-32-1COA of Formula: C4H5N3O2).

1-Methyl-3-nitro-1H-pyrazole (cas: 54210-32-1) 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. Pyrazole the presence of this nucleus in pharmacological agents of diverse therapeutic categories such as celecoxib, a potent anti-inflammatory, the antidepressant agent fezolamide have proved the pharmacological potential of the pyrazole moiety. COA of Formula: C4H5N3O2

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

Comparative Studies of Cathodically-Promoted and Base-Catalyzed Michael Addition Reactions of Levoglucosenone was written by Samet, Alexander V.;Niyazymbetov, Murat E.;Semenov, Victor V.;Laikhter, Andrei L.;Evans, Dennis H.. And the article was included in Journal of Organic Chemistry in 1996.Product Details of 5334-39-4 This article mentions the following:

Regioselective Michael addition of nitro and heterocyclic compounds to levoglucosenone, is effectively catalyzed by amines and also by cathodic electrolysis. In comparison to the base-catalyzed reaction, it was found that under electrochem. conditions the reaction proceeds under milder conditions and with higher yields. Cathodically-initiated Michael addition of thiols to levoglucosenone using small currents produces the previously unknown threo addition product in several instances. The normal erythro isomer, identified as the kinetic product, tends to be formed when large currents are used. In contrast, slow, low current electrolysis promote equilibration of the two forms so that erythro can be converted to threo by the retro reaction and readdn. Addition of 2-naphthalenethiol to (R)-(+)-apoverbenone is also reported. In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitro-1H-pyrazole (cas: 5334-39-4Product Details of 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–donor motifs, whether as a monocyclic ring or as a fused indazole ring. 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.Product Details of 5334-39-4

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

Fe(II)-Catalyzed Isomerization of 5-Chloroisoxazoles to 2H-Azirine-2-carbonyl Chlorides as a Key Stage in the Synthesis of Pyrazole-Nitrogen Heterocycle Dyads was written by Mikhailov, Kirill I.;Galenko, Ekaterina E.;Galenko, Alexey V.;Novikov, Mikhail S.;Ivanov, Alexander Yu.;Starova, Galina L.;Khlebnikov, Alexander F.. And the article was included in Journal of Organic Chemistry in 2018.Product Details of 73387-46-9 This article mentions the following:

2-(1H-Pyrazol-1-ylcarbonyl)-2H-azirines were synthesized by in situ trapping of 2H-azirine-2-carbonyl chlorides, generated by Fe(II)-catalyzed isomerization of 5-chloroisoxazoles, with pyrazoles. According to DFT calculations, the selectivity of nucleophilic substitution at the carbonyl group of 2H-azirine-2-carbonyl chloride by a pyrazole nucleophile, which is a mixture of two tautomers, is controlled by thermodn. factors. 2-(1H-Pyrazol-1-ylcarbonyl)-2H-azirines, e.g., I (X-rays single crystal structure shown), are excellent precursors for the preparation of two other pyrazole-nitrogen heterocycle dyads: 5-(1H-pyrazol-1-yl)oxazoles by photolysis and 1-(1H-pyrrol-2-ylcarbonyl)-1H-pyrazoles by a Ni(II)-catalyzed reaction with 1,3-dicarbonyl compounds 5-(1H-Pyrazol-1-yl)oxazoles show strong emission in acetonitrile at 360-410 nm with high quantum yields. In the experiment, the researchers used many compounds, for example, 3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9Product Details of 73387-46-9).

3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9) 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.Product Details of 73387-46-9

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