Tag: 100-200

New approach to derivatisation for oestradiol esters detection in animal blood plasma using negative chemical ionisation GC-MS was written by Liskova, Marcela;Cackova, Katarina;Rejtharova, Martina. And the article was included in Food Additives & Contaminants, Part A in 2021.Synthetic Route of C5H6ClN This article mentions the following:

In 1996, the EU prohibited the use of substances with anabolic action for food-producing animals (EU Directive 96/22/EC). In cases of illegal use of steroid hormones, these substances are usually applied to the animals in the form of esters. The reliable determination of intact steroid esters in animal tissues or body fluids is an unequivocal proof of illegal treatment of animals with EU prohibited anabolic substances. Previously our laboratory developed a sensitive method for determination of oestradiol benzoate and other steroid esters in blood plasma using LC-MS/MS, validated according to Commission Decision 2002/657/EC. This study describes a GC-MS method which has been developed for five oestradiol esters in blood plasma. The sample preparation procedure consisted of protein precipitation, phospholipids removal and cleaning on an alumina column. Oestradiol esters were derivatised with 2, 3, 4, 5, 6-pentafluorobenzoyl chloride (PFBCl) and pyridine in dichloromethane. The measurement of oestradiol esters was carried out by GC-MS/NCI with Cool On-Column injection. Methane was used as a neg. chem. ionisation reagent gas. The method for determination of oestradiol esters in blood plasma has been validated according to Commission Decision 2002/657/EC. Decision limits for all analytes were observed below 0.05 ng mL-1. The method is robust for bovine and porcine plasma analyses and can be applied both for screening and confirmatory determination in routine residue monitoring. In the experiment, the researchers used many compounds, for example, Pyridinehydrochloride (cas: 628-13-7Synthetic Route of C5H6ClN).

Pyridinehydrochloride (cas: 628-13-7) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Synthetic Route of C5H6ClN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis, crystal structure and fluorescence of a three-dimensional Cd(II) coordination polymer [Cd(μ_1,3-SCN^–)₂(μ-dmpo)]_n (dmpo = 3,5-dimethylpyridine N-oxide) was written by Shi, Jing-Min;Zhang, Feng-Xia;Huang, Jie;Liu, Lian-Dong. And the article was included in Chinese Journal of Structural Chemistry in 2006.Related Products of 3718-65-8 This article mentions the following:

A three-dimensional complex, [Cd(μ_1,3-SCN)₂(dmpo)]_n, was synthesized with μ_1,3-SCN^– and 3,5-dimethylpyridine N-oxide (dmpo) as mixed bridge ligands. The crystal belongs to monoclinic, space group C2/c with a 15.648(2), b 15.126(2), c 11.9773(15) Å, β 112.416(2)°, Z = 8, C₉H₉CdN₃OS₂, M_r = 351.71, d_c = 1.783 g/cm³, F(000) = 1376 and μ = 1.967 mm^-1. The structure was refined to R = 0.0260 and R_w = 0.0647 for 2186 observed reflections (1 > 2σ(I)). In the crystal the Cd(II) ions are coordinated by μ_1,3-SCN^– bridge ligands to form the crossing chains on the adjacent planes, and these chains are further joined by μ-dmpo mono-dentate bridge ligands leading to a three-dimensional structure. The complex exhibits a strong fluorescent emission. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Related Products of 3718-65-8).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Related Products of 3718-65-8

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Quantitation of genetox impurities using a surrogate standard approach was written by Wang, Heather;Nardi, Regina;Bereznitski, Yuri;Helmy, Roy;Waterhouse, David J.. And the article was included in Journal of Analytical Sciences, Methods and Instrumentation in 2013.Recommanded Product: 3-Hydroxy-6-methyl-2-nitropyridine This article mentions the following:

With the ever increasing complexity of active pharmaceutical ingredient (API) preparations, more potential genotoxic impurities (PGI’s) are being observed It is thus necessary to determine if these PGI’s are present in the final API’s, and if they are present, to ensure the levels are acceptable for any clin. uses. For PGI’s that have authentic standards available, quantitation can be accomplished in a straightforward manner. However, for PGI’s that are expected to form through rearrangements or side reactions, authentic standards may not be readily available, significantly complicating the anal. In this study we describe a surrogate standard approach for quantifying PGI’s that allows for relative response factor calculations of PGI species utilizing both gas chromatog.-mass spectrometry (GC-MS) and liquid chromatog.-mass spectrometry (LC-MS). In the experiment, the researchers used many compounds, for example, 3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2Recommanded Product: 3-Hydroxy-6-methyl-2-nitropyridine).

3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Recommanded Product: 3-Hydroxy-6-methyl-2-nitropyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The preparation and coordination chemistry of 2,2′:6′,2″-terpyridine macrocycles – 1 was written by Constable, Edwin C.;Lewis, Jack. And the article was included in Polyhedron in 1982.Electric Literature of C7H7ClN2 This article mentions the following:

Derivatives of 2,2′:6′,2”-terpyridine were prepared with the intention of forming macrocycles incorporating the 2,2′:6′,2”-terpyridyl moiety. Bis(methylhydrazino)phenylterpyridine I (R = MeNNH₂) and a number of metal complexes of this novel pentadentate ligand were prepared Thus, Ortoleva-King reaction of 2-acetyl-6-bromopyridine with iodine and pyridine gave pyridinium iodide II. Cyclocondensation of II and 2-bromo-6-cinnamoylpyridine in refluxing HOAc containing NH₄OAc gave I (R = Br). Reaction of the latter with MeNHNH₂ gave I (R = MeNNH₂) which formed colored complexes with Cr, Mn, Fe, Co, and Ni. In the experiment, the researchers used many compounds, for example, 1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3Electric Literature of C7H7ClN2).

1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase and 140.4 kJ·mol−1 in the gas phase. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Electric Literature of C7H7ClN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Improved Synthesis of Mono- and Disubstituted 2-Halonicotinonitriles from Alkylidene Malononitriles was written by Longstreet, Ashley R.;Campbell, Brian S.;Gupton, B. Frank;McQuade, D. Tyler. And the article was included in Organic Letters in 2013.Application In Synthesis of 2-Chloro-4-methylpyridine-3-carbonitrile This article mentions the following:

Pyridines with 2,3,4 and/or 5 substitution remain challenging to prepare Existing strategies to form multisubstituted 2-halonicotinonitriles via enamines suffer from dimerization of the starting alkylidene malononitriles resulting in low yields. Through alteration of reaction conditions, a new high yielding method into enamines was realized by condensing DMF-DMA and alkylidene malononitriles in the presence of substoichiometric acetic anhydride. Cyclization of the resulting enamines under Pinner conditions provided 2-halonicotinonitriles, e.g., I, in high overall yields. In the experiment, the researchers used many compounds, for example, 2-Chloro-4-methylpyridine-3-carbonitrile (cas: 65169-38-2Application In Synthesis of 2-Chloro-4-methylpyridine-3-carbonitrile).

2-Chloro-4-methylpyridine-3-carbonitrile (cas: 65169-38-2) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. Application In Synthesis of 2-Chloro-4-methylpyridine-3-carbonitrile

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Cellulose as recyclable organocatalyst for ipso-hydroxylation of arylboronic acids was written by Laskar, Khairujjaman;Paul, Subham;Bora, Utpal. And the article was included in Tetrahedron Letters in 2019.Quality Control of 5-Hydroxy-2-methoxylpyridine This article mentions the following:

Cellulose catalyzed oxidative hydroxylation of aryl and hetero-arylboronic acids to the corresponding phenols under metal and base free strategy was demonstrated. The sustainable ipso-hydroxylation took place using hydrogen peroxide as an oxidant in water under mild condition in shorter period of time. Easy recovery and reusability of heterogeneous catalyst without significant loss in catalytic yield was seen and the protocol was environmentally benign. In the experiment, the researchers used many compounds, for example, 5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0Quality Control of 5-Hydroxy-2-methoxylpyridine).

5-Hydroxy-2-methoxylpyridine (cas: 51834-97-0) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Quality Control of 5-Hydroxy-2-methoxylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Discovery of (E)-3-((Styrylsulfonyl)methyl)pyridine and (E)-2-((Styrylsulfonyl)methyl)pyridine Derivatives as Anticancer Agents: Synthesis, Structure-Activity Relationships, and Biological Activities was written by Lu, Tiangong;Goh, Aik Wye;Yu, Mingfeng;Adams, Julian;Lam, Frankie;Teo, Theodosia;Li, Peng;Noll, Ben;Zhong, Longjin;Diab, Sarah;Chahrour, Osama;Hu, Anran;Abbas, Abdullahi Y.;Liu, Xiangrui;Huang, Shiliang;Sumby, Christopher J.;Milne, Robert;Midgley, Carol;Wang, Shudong. And the article was included in Journal of Medicinal Chemistry in 2014.Related Products of 15128-90-2 This article mentions the following:

ON01910.Na is a highly effective anticancer agent that induces mitotic arrest and apoptosis. Clin. studies with ON01910 in cancer patients have shown efficacy along with an impressive safety profile. While ON01910 is highly active against cancer cells, it has a low oral availability and requires continuous i.v. infusion or multiple gram doses to ensure sufficient drug exposure for biol. activity in patients. We have identified two novel series of styrylsulfonyl-methylpyridines. Lead compounds 8, 9a, 18 and 19a are highly potent mitotic inhibitors and selectively cytotoxic to cancer cells. Impressively, these compounds possess excellent pharmaceutical properties and two lead drug candidates 9a and 18 demonstrated antitumor activities in animal models. In the experiment, the researchers used many compounds, for example, 3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2Related Products of 15128-90-2).

3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase and 140.4 kJ·mol−1 in the gas phase. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Related Products of 15128-90-2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Designing of novel zinc(II) Schiff base complexes having acyl hydrazone linkage: study of phosphatase and anti-cancer activities was written by Dasgupta, Sanchari;Karim, Suhana;Banerjee, Saswati;Saha, Moumita;Das Saha, Krishna;Das, Debasis. And the article was included in Dalton Transactions in 2020.Name: Phenyl(pyridin-2-yl)methanone This article mentions the following:

Three asym. tridentate acyl hydrazone Schiff base ligands L1, L2 and L3 were prepared via condensation of 4-methoxybenzohydrazide with picolinaldehyde, 1-(pyridin-2-yl)ethanone and phenyl(pyridin-2-yl)methanone, resp. Three bio-relevant mononuclear Zn(II) complexes [Zn(L1)Cl₂]·2H₂O (1), [Zn(L2)Cl₂] (2) and [Zn(L3)Cl₂] (3) were synthesized by treatment of Zn(II) chloride with the corresponding Schiff base ligands and characterized by the usual physicochem. techniques. The solid state structures of complexes 1 and 3 were evaluated by single crystal x-ray anal. All complexes were able to hydrolyze the P-O bond of the phosphate monoester in 90% (volume/volume) DMSO-H₂O medium using 4-nitrophenylphosphate (4-NPP) as model substrate and the trend in their activity is 1 ≈ 2 > 3. On considering the highly efficient hydrolysis properties, complexes 1–3 were tested as potential therapeutic agents for cancer using HCT116 (human colorectal carcinoma), HepG2 (human hepatocellular carcinoma) and A549 (human nonsmall lung carcinoma) cells. Complex 2 showed the highest IC₅₀ values for anti-cancer activity towards all three cell lines among the three complexes and complex 3 showed the least activity as observed in the phosphatase activity study. The internucleosomal degradation of DNA during apoptosis can be detected by cell death detection ELISA. DNA fragmentation that leads to cell death was examined and when induced by complex 2 in HepG2 cells a significant level of DNA fragmentation was observed at regular intervals of time. In the experiment, the researchers used many compounds, for example, Phenyl(pyridin-2-yl)methanone (cas: 91-02-1Name: Phenyl(pyridin-2-yl)methanone).

Phenyl(pyridin-2-yl)methanone (cas: 91-02-1) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Pyridine derivatives are also useful as small-molecule α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Name: Phenyl(pyridin-2-yl)methanone

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

A multi-colorimetric probe to discriminate between heavy metal cations and anions in DMSO-H₂O with high selectivity for Cu²⁺ and CN^–: study of logic functions and its application in real samples was written by Hamukwaya, Eunike;Naimhwaka, Johannes;Uahengo, Veikko. And the article was included in RSC Advances in 2021.Name: Phenyl(pyridin-2-yl)methanone This article mentions the following:

A ditopic multi-colorimetric probe based on the phenylpridyl-thioic moiety (EN) was synthesized via a Schiff base reaction mechanism and characterized using ¹H NMR and UV-vis spectroscopy. The colorimetric analyses carried out revealed that EN was capable of discriminating between a number of heavy metal cations via coordination induced charge transfer, as well as between anions through hydrogen bonding induced charge transfer, in DMSO-H₂O (9 : 1). In particular, the ditopic probe could spectrally and colorimetrically recognize the most toxic heavy metal cations of Cd²⁺, Pb²⁺ and Hg²⁺, among others, in DMSO-H₂O. Addnl., EN was selective and sensitive to the presence of CN^–, F^–, AcO^– and H₂PO₄^– in the same solvent system as cations. The reversibility and reproducibility studies showed that EN exhibited complementary IMP/INH logic functions, based on color and spectral switching (ON/OFF), modulated by F^–/Al³⁺. The real time application of the probe was tested on food grade products to detect the presence of F^– in toothpastes and mouthwash dissolved in water, as well as cations in underground water (normally saline), which displayed substantial responses. Thus, EN displayed an excellent scope of response and can thus be developed for real time sensing kits, which could be used instantly in on-field anal. Theor. studies were conducted to complement the exptl. work. In the experiment, the researchers used many compounds, for example, Phenyl(pyridin-2-yl)methanone (cas: 91-02-1Name: Phenyl(pyridin-2-yl)methanone).

Phenyl(pyridin-2-yl)methanone (cas: 91-02-1) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. Many analogues of pyridine are known where N is replaced by other heteroatoms . Substitution of one C–H in pyridine with a second N gives rise to the diazine heterocycles (C4H4N2), with the names pyridazine, pyrimidine, and pyrazine.Name: Phenyl(pyridin-2-yl)methanone

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Addition of C-H Bonds of Pyridine Derivatives to Alkenes Catalyzed by Zirconium Complexes Bearing Amine-Bridged Bis(phenolato) Ligands was written by Sun, Qiu;Chen, Ping;Wang, Yaorong;Luo, Yunjie;Yuan, Dan;Yao, Yingming. And the article was included in Inorganic Chemistry in 2018.Formula: C8H11N This article mentions the following:

Cationic zirconium complexes in situ generated from zirconium dibenzyl complexes bearing amine-bridged bis(phenolato) ligands have been developed to catalyze addition of C(sp²)-H and C(sp³)-H bonds of pyridine derivatives to alkenes. A series of zirconium complexes bearing different ligands have been synthesized, and their activities in catalyzing addition of C(sp³)-H bonds of pyridine derivatives to alkenes have been studied and compared. Both reaction activity and regioselectivity are influenced by electronic and steric properties of ligand backbones. In addition, a cationic zirconium complex has been isolated and structurally characterized to shed some light on reaction mechanism. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4Formula: C8H11N).

2-Isopropylpyridine (cas: 644-98-4) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Formula: C8H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem