Day: January 6, 2023

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

Conventional, grinding and microwave-assisted synthesis, biological evaluation of some novel pyrazole and pyrazolone derivatives was written by Naguib, H. M.;Shaban, S. N.;Abdelghaffar, N. F.;Dauoud, N. T.;Sayed, G. H.;Anwer, K. E.. And the article was included in Journal of Basic and Environmental Sciences in 2021.Application of 51395-52-9 This article mentions the following:

Under conventional, grinding and microwave methods, reaction of 3-methyl-1H-pyrazol-5-one with benzene diazonium chloride, 4-carboxybenzenediazonium chloride and nitrous acid furnished the diazenyl derivatives resp. Reaction of 4-((3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-4-yl)diazenyl)benzoic acid with salicyladehyde and 4-(chlorodiazenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one with malononitrile followed by hydrazine hydrate afforded pyrazolones resp. 3-Methyl-1H-pyrazol-5-one was converted to 4-bromopyrazolone, which when allowed to react with urea, thiourea, o-phenylenediamine, 2-amino-3-hydroxypyridine and 2-amino-5-methylphenyl furnished 4-aminopyrazolones, resp. While its reaction with p-phenylenediamine in 1:2 ratio gave bis-pyrazole derivative Also, the reaction of 3-methyl-1H-pyrazol-5-one toward thiosemicarbazide, thiourea, urea and guanidine hydrochloride gave the pyrazole derivatives, resp. The reaction of 1-(5-methyl-4H-pyrazol-3-yl)thiourea with benzaldehyde gave Schiff base, while its reaction with Et chloroacetate gave the thioxoimidazolidinone derivative, which on reaction with thiosemicarbazide afforded imidazotriazolothione derivative Also, the reactivity of pyrazole reacted with salicyladehyde and o-chlorobenzaldehyde was investigated to afford the corresponding Schiff base, resp. These new scaffolds were screened for in vitro antimicrobial and cytotoxic activities. Most analogs revealed excellent to good results. In the experiment, the researchers used many compounds, for example, 4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9Application of 51395-52-9).

4-Bromo-3-methyl-1H-pyrazol-5(4H)-one (cas: 51395-52-9) 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. 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.Application of 51395-52-9

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

Cyanoethylhydrazide in the preparation of nitrogen heterocycles. III. Heterocyclic 7-rings through the reaction of 1,3-dicarbonyl compounds with cyanoacetylhydrazide was written by Ried, W.;Kocher, E. U.. And the article was included in Angewandte Chemie in 1958.Electric Literature of C6H9N3O This article mentions the following:

Acetylacetone with cyanoacetylhydrazide in alc. in the presence of a few drops AcOH gives the mono(cyanoacetylhydrazone) (I), m. 165-6°, very soluble in dilute NaOH. The addition of at least 2 moles aqueous NaOH solution to I followed by acidification of the resulting yellow solution with AcOH yields MeC:C(CN).C(OH):N.N:CMe.CH₂ (or ketone) (II), yellow, m. 237-8°, very soluble in dilute NaOH, soluble in dilute HCl. With HNO₂, II gives orange leaves, m. 183-4°. In the same way, benzoylacetone and cyanoacetylhydrazide give PhCOCH₂CMe:NNHCOCH₂CN, (III), m. 122-3° soluble in dilute NaOH. 1-Cyanoacetyl-3-methyl-5-phenylpyrazole, m. 153-4°, may be prepared by treating III with aqueous alc. HCl. III with base yields PhC:C(CN).C(OH):N.N.CMe.CH₂ (or ketone), light yellow needles, m. 257-8° soluble in dilute NaOH and dilute HCl, gives red needles, m. 216-17°, with HNO₂. 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. 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.Electric Literature of C6H9N3O

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

Pd-Catalyzed N-Arylation of Heteroarylamines was written by Yin, Jingjun;Zhao, Matthew M.;Huffman, Mark A.;McNamara, James M.. And the article was included in Organic Letters in 2002.Reference of 3528-58-3 This article mentions the following:

The palladium-catalyzed N-(hetero)arylation of a number of heteroarylamines including 2-aminopyridines, 2-aminothiazoles, and their analogs has been realized using Xantphos as the ligand. Weak bases such as Cs₂CO₃, Na₂CO₃, and K₃PO₄ were used in most cases to allow for the introduction of functional groups. Choice of the base and solvent was critical for the success of these reactions. In the experiment, the researchers used many compounds, for example, 1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3Reference of 3528-58-3).

1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3) 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 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.Reference of 3528-58-3

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

Development of a high-throughput screening analysis for 288 drugs and poisons in human blood using Orbitrap technology with gas chromatography-high resolution accurate mass spectrometry was written by Pan, Meiru;Xiang, Ping;Yu, Zhiguo;Zhao, Yunli;Yan, Hui. And the article was included in Journal of Chromatography A in 2019.SDS of cas: 73387-46-9 This article mentions the following:

The screening anal. for drugs and poisons always symbolizes the capabilities of a forensic laboratory Due to the rapid emergence of new compounds in clin. and forensic intoxication cases, sensitive and specific methods are necessary for the screening of wide range of target compounds A novel high-throughput screening method has been developed for the toxicol. anal. of 288 drugs and poisons in human blood using Orbitrap technol. with gas chromatog.-high resolution mass spectrometry (GC-HRMS). This method allows for the fast detection and identification of high-throughput forensically important drugs and poisons, e.g., drugs of abuse (cocaine, amphetamines, synthetic cannabinoids, opiates, hallucinogen), sedative-hypnotics, antidepressants, non-steroidal anti-inflammatory drugs, pesticides (acaricides, fungicides, insecticides, nematicides), and cardiovascular agents in one single GC-Q Exactive run. After a simple extraction with Et ether and buffer, following centrifugation, the supernatant was injected into the system. For detection, spiked blood samples were analyzed by Orbitrap-GC-HRMS using an electrospray ionization in full scan mode with a scan range from 40 to 650 (m/z). The identification of drugs and poisons in the samples was carried out by searching the accurate mol. mass of characteristic fragment ions, ion rations and retention time (RT) against the inhouse library that the authors developed with 70 ev electron energy. The limit of detection (LOD) for most compounds (249 in a total of 288 compounds) was below 100 ng/mL. For selectivity, no substances have been identified in drug-free blood samples from six different sources, and the method was suitable for the recovery and the carryover. The coefficient of variation (CV) of the RTs was below 0.99% in all reproducibility experiments Mass accuracy was always better than 3 ppm, corresponding to a maximum mass error of 1.04 millimass units (mmu). The developed method was applied to 136 real samples from forensic cases, demonstrating its suitability for the sensitive and fast screening of high-throughput drugs in human blood samples. In the experiment, the researchers used many compounds, for example, 3-(4-Bromophenyl)-1H-pyrazole (cas: 73387-46-9SDS of cas: 73387-46-9).

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

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

Reactions of β-aminoenones with acetylhydrazine, semicarbazide and methoxycarbonylhydrazine. Synthesis of 1-acetyl-, 1-carboxamide- or methyl 1-carboxylated pyrazole derivatives was written by Alberola, Angel;Calvo, Luis;Ortega, Alfonso Gonzalez;Sadaba, M. Luisa;Sanudo, M. Carmen;Granda, Santiago Garcia;Rodriguez, Elena Garcia. And the article was included in Heterocycles in 1999.Product Details of 934-48-5 This article mentions the following:

Acetylhydrazine, semicarbazide and methoxycarbonylhydrazine react with β-aminoenones to give regioselectively the corresponding N-acetyl- or N-carboxypyrazole derivatives The reactions are highly regioselective and occur via 5-hydroxypyrazolines, which in several cases can be isolated and characterized. In the experiment, the researchers used many compounds, for example, 3,5-Dimethyl-1H-pyrazole-1-carboxamide (cas: 934-48-5Product Details of 934-48-5).

3,5-Dimethyl-1H-pyrazole-1-carboxamide (cas: 934-48-5) 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.Product Details of 934-48-5

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

Synthesis of vicinal aminoiodo- and (acetylamino)iodo-1-alkylpyrazoles was written by Tretyakov, E. V.;Vasilevsky, S. F.. And the article was included in Izvestiya Akademii Nauk, Seriya Khimicheskaya in 1996.Safety of 1-Methyl-3-nitro-1H-pyrazole This article mentions the following:

One-pot acylation-iodination of 3- and 5-amino-1-alkylpyrazoles gave 3- and 5-acetamido-4-iodo-1-alkylpyrazoles. Reduction of iodonitropyrazoles with SnCl₂ in HCl gave 3- and 5-iodo- and 3,5-diiodo-4-amino-1-methylpyrazole. In the experiment, the researchers used many compounds, for example, 1-Methyl-3-nitro-1H-pyrazole (cas: 54210-32-1Safety of 1-Methyl-3-nitro-1H-pyrazole).

1-Methyl-3-nitro-1H-pyrazole (cas: 54210-32-1) 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 can be selectively lithiated at different carbons and subsequently react with electrophiles depending on the substitution patterns.Safety of 1-Methyl-3-nitro-1H-pyrazole

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