Tag: M.W=50-100

Li, Yong-xiang published the artcileSolubility of 1-methyl-4-nitropyrazole in seventeen pure solvents at temperatures from 283.15 K to 323.15 K, Product Details of C4H6N2, the publication is Fluid Phase Equilibria (2018), 80-89, database is CAplus.

Knowledge of solubility for 1-methyl-4-nitropyrazole (1-M-4-NP) in different solvents is important for its purification and further theor. studies. In this paper, the solubility of 1-M-4-NP in toluene, 1,2-dichlorobenzene, water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, Me acetate, Et acetate, acetone, butanone, acetic acid and acetonitrile were determined at T = (283.15, 288.15, 293.15, 298.15, 303.15, 308.15, 313.15, 318.15 and 323.15) K under atm. pressure (P = 0.1 MPa) by a gravimetric method. The results showed that the solubility increases with rise of temperature in all selected solvents and the solubility in acetone increases fastest. In alc. solvents, the solubility decreases with the increasing in the number of carbon atoms in the alc. Addnl., melting temperature and fusion enthalpy of 1-M-4-NP were measured by differential scanning calorimetry (DSC). Besides, the solubility values were correlated by the modified Apelblat equation, the polynomial empirical equation, λh equation and NRTL model. Since the correlation coefficients (R²) of the four models are greater than 0.9900 and the largest values of the root-mean-square was 7.00 × 10^-2, four correlation models can be adopted to correlate the solubility data. On the basis of the NRTL model, the dissolution thermodn. properties, including enthalpy, entropy and Gibbs energy were calculated and discussed as well according to the exptl. data, from which we conclude that the dissolution of 1-M-4-NP is an spontaneous process. Furthermore, solubility values and thermodn. relations of 1-M-4-NP in selected solvents would be invoked as fundamental data and models regarding the purification process of 1-M-4-NP.

Fluid Phase Equilibria published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Product Details of C4H6N2.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Li, Guangbin published the artcileDiazole and triazole inhibition of nitrification process in return activated sludge, Safety of 1-Methylpyrazole, the publication is Chemosphere (2020), 124993, database is CAplus and MEDLINE.

Azoles are emerging contaminants that are resistant to biodegradation during wastewater treatment. Their presence has been widely reported in wastewater effluents and receiving waters. In this work, the potential inhibition of nitrification process by six different azole compounds in wastewater treatment plants was investigated in batch bioassays. The azoles studied included three diazoles: pyrazole (Pz); 1-methylpyrazole (MePz); 3,5-dimethylpyrazole (DMePz); and three triazoles: 1,2,4-triazole (Tz); benzotriazole (BTz); and 5-Me benzotriazole (MeBTz). The concentration of azoles causing 50% inhibition (IC₅₀) increased (azoles became less inhibitory) in the following order (mg L^-1): BTz (1.99) < MeBTz (2.18) < Pz (2.69) < Tz (3.53) < DMePz (17.3) < MePz (49.6). No clear structure-inhibitory relationships were found using Log P and pKa as structural properties. The toxicity of any given azole may be related to the role of substituent groups on disabling/enabling binding to the active sites of metallo-enzymes in nitrifying microorganisms. This is exemplified by the low toxicity of MePz, which has a cyclic N blocked by a Me group. The observed inhibition caused to nitrifying bacteria is more severe than their cytotoxicity to other target organisms (e.g., methanogens and heterotrophic bacteria), suggesting a specific inhibition to the copper-containing enzyme, ammonium monooxygenase, in ammonia oxidizing nitrifying microorganisms.

Chemosphere published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Safety of 1-Methylpyrazole.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Sun, Xiaohua published the artcileSynthesis of Quinoxaline Derivatives as Intermediates to Obtain Erdafitinib, Related Products of pyrazoles-derivatives, the publication is Pharmaceutical Chemistry Journal (2021), 55(9), 951-953, database is CAplus.

In this work, quinoxaline derivative 7-bromo-2-(1-methyl-1H-pyrazol-4-yl)quinoxaline, which is an essential intermediate to obtain drug erdafitinib, has been synthesized in reasonably good yield using 4-bromobenzene-1,2-diamine and 2-bromo-1-(1-methyl-1H-pyrazol-4-yl)ethan-1-one as raw materials, triethylene diamine (DABCO) as catalyst, and THF as solvent. To the best of authors’ knowledge, this is the first time 7-bromo-2-(1-methyl-1H-pyrazol-4-yl)quinoxaline has been acquired by the proposed method.

Pharmaceutical Chemistry Journal published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C10H14N2O, Related Products of pyrazoles-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Labroli, Marc A. published the artcileA convergent preparation of the CHK1 inhibitor MK-8776 (SCH 900776), Related Products of pyrazoles-derivatives, the publication is Tetrahedron Letters (2016), 57(24), 2601-2603, database is CAplus.

This Letter describes the development of a convergent, efficient route to the CHK1 inhibitor MK-8776, I. This synthetic approach relies upon the cyclization of a bispyrazole adduct 10 with a optically pure β-keto nitrile 9 to construct the pyrazolo[1,5-a]pyrimidine scaffold in a single step.

Tetrahedron Letters published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Related Products of pyrazoles-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Kwak, Se Hun published the artcileN-Aminopyridinium Ylide-Directed, Copper-Promoted Amination of sp² C-H Bonds, HPLC of Formula: 930-36-9, the publication is Journal of Organic Chemistry (2019), 84(20), 13022-13032, database is CAplus and MEDLINE.

N-Aminopyridinium ylides were used as monodentate directing groups for copper-promoted C-H/N-H coupling of sp² C-H bonds with pyrazoles, imidazoles, and sulfonamides. Reactions proceed in fluorinated alc. solvents at elevated temperatures and require use of 1.3-3 equiv of copper(II) acetate. This appears to be the first method for copper-promoted C-H/N-H coupling directed by a removable monodentate auxiliary in absence of added ligands.

Journal of Organic Chemistry published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, HPLC of Formula: 930-36-9.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Guo, Heng-jie published the artcileSolubility and thermodynamic properties of a kind of explosives in four binary solvents, Formula: C4H6N2, the publication is Journal of Molecular Liquids (2017), 313-327, database is CAplus.

The solubility values of 1-methyl-3,4,5-trinitropropyrazole (MTNP) in four different binary solvents of water + (methanol, ethanol, 1-propanol and 2-propanol) at nine different temperatures from (283.15 to 323.15) K were firstly measured by a gravimetric method under atm. pressure. The exptl. data showed that the solubility of MTNP increases with the increasing temperature in binary solvent mixtures Besides, the dissolving capacity of MTNP decreased with the increasing water mole fraction ranging from 0.1000 to 0.7000 at a temperature Addnl., results of these measurements were correlated by the modified Apelblat equation, vant’t Hoff equation, CNIBS/R-K model and Jouyban-Acree model, and all of the models provided a satisfactory results in binary solvents. In addition, the thermodn. properties of solution in different binary solvent mixtures, such as enthalpy, Gibbs energy and entropy can be calculated by the vant’t Hoff equation and the Gibbs equation. Apparent thermodn. quantities of mixing were also calculated for MTNP using values of the ideal solubility reported in the literature. Solid-liquid surface tension and surface entropy factor of MTNP were estimated by using the exptl. solubility data.

Journal of Molecular Liquids published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Formula: C4H6N2.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

de Araujo, Marcos Lopes published the artcileThe effect of additives (pyrazine, pyrazole and their derivatives) in the oxidation of 2-butanol with FeCl₃-H₂O₂ in aqueous solutions, Related Products of pyrazoles-derivatives, the publication is Catalysis Today (2021), 163-170, database is CAplus.

In the present paper we described the oxidation of 2-butanol as a representative of secondary aliphatic alcs. The oxidizing system FeCl₃-H₂O₂ was used. A kinetic study of the oxidation reaction has been carried out. Different substituted pyrazines and pyrazoles, namely 2-pyrazinecarboxylic acid (PCA), 5-methyl-2-pyrazinecarboxylic acid (5MPCA), 2-methylpyrazine (2MPZINE), 3-(trifluoromethyl)pyrazole (3TFMPZOLE), 3-methylpyrazole (3MPZOLE) and 1-methylpyrazole (1MPZOLE) were added as cooperating ligands in aqueous solutions DFT based calculations were also used in order to evaluate the different results obtained. Addition of PCA, 5MPCA and 3TFMPZOLE led to a better reaction performance, while the other ligands led to lower accumulation of products than the reaction without additives. Performed DFT studies suggested that the metal-ligand π-backbonding might be responsible for the reaction activity increase, while ligands more strongly bonded to Fe make it more difficult the access to the metal, leading to lower yields.

Catalysis Today published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Related Products of pyrazoles-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Belen’kii, L. I. published the artcileAlternative mechanisms of electrophilic substitution in azole series, Product Details of C4H6N2, the publication is Russian Chemical Bulletin (2016), 65(6), 1441-1447, database is CAplus.

Data on three mechanisms of aromatic electrophilic substitution in azole series were presented. First of them is similar to an ordinary addition-elimination mechanism including the formation of a cationic σ-complex (Wheland intermediate). The second mechanism is realized according to the elimination-addition scheme and includes a protonation or a formation of a complex on the pyridine N atom, proton abstraction from the C atom adjacent to the above N atom, and addition of a cationoid reagent to the ylide (carbene) formed. The third mechanism proposed by the present authors can be realized for azoles having three and two N atoms of the pyridine type. It does not require the preliminary N-protonation or complex formation and occurs due to a strong electron withdrawing effect of several pyridine atoms, resulting in the CH-deprotonation followed by the interaction of the carbanion formed with a cation under mild conditions.

Russian Chemical Bulletin published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Product Details of C4H6N2.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Miller, Susanne L. published the artcileC-H Borylation Catalysts that Distinguish Between Similarly Sized Substituents Like Fluorine and Hydrogen, Product Details of C4H6N2, the publication is Organic Letters (2019), 21(16), 6388-6392, database is CAplus and MEDLINE.

By modifying ligand steric and electronic profiles it is possible to C-H borylate ortho or meta to substituents in aromatic and heteroaromatic compounds, where steric differences between accessible C-H sites are small. Dramatic effects on selectivities between reactions using B₂pin₂ or 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (HBpin) are described for the 1st time. Judicious ligand and borane combinations give highly regioselective C-H borylations on substrates where typical borylation protocols afford poor selectivities.

Organic Letters published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Product Details of C4H6N2.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Patil, Dayanand published the artcileNovel crown ether functionalized imidazolium-based acidic ionic liquid catalyzed synthesis of pyrazole derivatives under solvent-free conditions, Related Products of pyrazoles-derivatives, the publication is Research on Chemical Intermediates (2015), 41(9), 6843-6858, database is CAplus.

An innovative designed novel crown ether functionalized imidazolium-based reusable acidic ionic liquid [crown ether MIm] [HSO₄] has been efficiently implemented for the synthesis of pyrazole derivatives using various substituted enaminones, hydrazine hydrate and Ph hydrazine under solvent-free conditions. Structural novelty and task efficiency of the catalyst, high yields of desired products, greener approach attributing high atom economy (green chem. method) and solvent-free conditions render this protocol suitable to cope with the current demand in contemporary organic chem. The inventive idea of utilizing crown ether functionalized ionic liquid as a catalyst was for the first time demonstrated in this protocol. The synthesis of the target compounds was achieved using [6-[1,4,7,10,13-benzopentaoxacyclopentadecin-15-yl]hexyl]imidazolium sulfate as a catalyst. Starting materials included hydrazine, phenylhydrazine and enaminone derivatives [(amino)alkenone derivatives] such as 3-(dimethylamino)-1-phenyl-2-propen-2-one, 3-(dimethylamino)-1-(2-furanyl)-2-propen -1-one, 2-[(dimethylamino)methylene]-1,3-cyclohexanedione. The title compounds thus formed included pyrazole derivatives and analogs, such as 3-phenyl-1H-pyrazole, 3-(2-furanyl)-1H-pyrazole, 1,5,6,7-tetrahydro-4H-indazol-4-one (indazole derivatives).

Research on Chemical Intermediates published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Related Products of pyrazoles-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics