Day: January 6, 2023

Polystyrene supported Dichloro-(8-aminoquinoline)-Palladium(II) complex catalyzed C-H bond activation for ortho-acylation of 2-aryl pyridines was written by Perumgani, C. Pullaiah;Parvathaneni, Sai Prathima;Kodicherla, Balaswamy;Keesara, Srinivas;Mandapati, Mohan Rao. And the article was included in Inorganica Chimica Acta in 2017.Computed Properties of C12H11N This article mentions the following:

Polystyrene-supported Dichloro-(8-aminoquinoline)-Pd(II) complex C was synthesized and its catalytic efficiency was evaluated for ortho-acylation of 2-arylpyridines with alcs. to form aryl ketones via cross dehydrogenative coupling [e.g., 2-phenylpyridine + benzyl alc. → 2-(2-pyridyl)benzophenone (91%)]. In addition in the presence of Pd(II) complex, toluene derivatives were also employed as an effective coupling partner for synthesis of aromatic ketones. Furthermore, this catalyst was highly stable and could be easily recovered by simple filtration and reused for four cycles with no significant decrease in its activity and selectivity. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Computed Properties of C12H11N).

2-(m-Tolyl)pyridine (cas: 4373-61-9) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. Pyridine derivatives are also useful as small-molecule α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Computed Properties of C12H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The lipophilicity and hydrogen bond strength of pyridine-N-oxides and protonated pyridine-N-oxides was written by Abraham, Michael H.;Honcharova, Lesya;Rocco, Silvana A.;Acree, Jr William E. Jr.;De Fina, Karina M.. And the article was included in New Journal of Chemistry in 2011.Application In Synthesis of 3,5-Dimethylpyridine 1-oxide This article mentions the following:

Water-solvent partition coefficients for 4-nitropyridine-N-oxide have been determined in six solvent systems, and solubilities measured in water and 37 solvents. The combined data are used to obtain Abraham descriptors for 4-nitropyridine-N-oxide as follows: E = 0.934, S = 1.92, A = 0.21, B = 0.76, V = 0.9082 and L = 5.246; literature data on partition coefficients were used to calculate descriptors for 11 other pyridine-N-oxides as well as quinoline-N-oxide and isoquinoline-N-oxide. In all cases, the N-oxides were shown to be stronger hydrogen bond bases than the corresponding pyridines, thus leading to a decrease in lipophilicity. An unexpected observation is that of the hydrogen bond acidity of the N-oxides due, we suggest, to the pos. nitrogen atom in the moiety N(+) → O(-). This leads to an even sharper decrease in the N-oxide lipophilicity in non-polar solvents. We have also used literature data to determine the 1 : 1 hydrogen bond basicity, βH2, of a number of pyridine-N-oxides; again, this basicity is significantly larger than that of the corresponding pyridines. Protonation of pyridine-N-oxides removes all hydrogen bond basicity (B = 0.00), but the protonated compounds are strong hydrogen bond acids. For protonated pyridine-N-oxide itself, E = 0.514, S = 2.62, A = 1.51, B = 0.00, V = 0.7555 and the ionic descriptor J⁺ = 0.894; protonated 4-nitropyridine-N-oxide with A = 2.05 is a very strong hydrogen bond acid indeed. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Application In Synthesis of 3,5-Dimethylpyridine 1-oxide).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. 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 3,5-Dimethylpyridine 1-oxide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Fluorocyano-benzenes and -pyridines was written by Finger, G. C.;Dickerson, D. R.;Adl, Touradj;Hodgins, T.. And the article was included in Chemical Communications (London) in 1965.Computed Properties of C6H3FN2 This article mentions the following:

Chlorobenzonitriles stirred and heated at 160-200° with anhydrous KF in Me₂SO₂ (CA 57, 12358i; 59, 1585a) gave 50-80% of the following I (R = mono- or disubstituted) (R and m.p. CN or b.p./mm. given): 2-F, 103°/35; 4-F, 38°; 2,4-F₂, 46°; 2,6-F₂, 99°/20; 2-F-5-CF₃ (II), 99°/27. Similarly, 2-chloro-pyridinecarbonitriles afforded 54-88% of the following III (R = CN) derivatives (R and m.p. given): 3-CN, 30°; 4-CN, 33°; 5-CN, 51°; 6-CN, 34°. 3-Bromo-4-chloro-α,α,α-trifluorotoluene heated at 145° for 42 hrs. with excess CuCN and KF in HCONMe₂ produced 57% II and 43% I (R = 4-5-Cl-CF₃), m. 39°. In the experiment, the researchers used many compounds, for example, 6-Fluoropicolinonitrile (cas: 3939-15-9Computed Properties of C6H3FN2).

6-Fluoropicolinonitrile (cas: 3939-15-9) 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. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Computed Properties of C6H3FN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The deoxydative substitution of pyridine N-oxides. Part XVI. Carbon-13 spectra of some tetrahydropyridines. The structure of the tetrahydropyridines from 3,5-lutidine 1-oxide and mercaptans in acetic anhydride was written by Kokosa, John M.;Chu, Ih;Bauer, Ludwig;Egan, Richard S.. And the article was included in Journal of Heterocyclic Chemistry in 1978.Computed Properties of C7H9NO This article mentions the following:

The reaction of 3,5-lutidine 1-oxide (I) with Me₃CSH in Ac₂O, with or without Et₃N, was reinvestigated. There was obtained 2-tert-butylthio-3,5-lutidine as the major product, a small quantity of 5-(tert-butylthiomethyl)-3-picoline, 1-acetyl-2,3-diacetoxy-3,5-dimethyl-6-tert-butylthio-1,2,3,6-tetrahydropyridine (which represents a structure revision, F. M. Hershenson, et al., 1969) and 1-acetyl-2,6-dihydroxy-3-tert-butylthio-3,5-dimethyl-1,2,3,6-tetrahydropyridine. A similar reaction of I with 1-adamantyl mercaptan furnished 2-(1-adamantylthio)-3,5-lutidine and 1-acetyl-2,3-diacetoxy-3,5-dimethyl-6-(1-adamantylthio)-1,2,3,6-tetrahydropyridine. The structures of these new tetrahydropyridines were established primarily by ¹³C-NMR spectra. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Computed Properties of C7H9NO).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) 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. 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.Computed Properties of C7H9NO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Interactions of sodium polystyrene sulfonate with 4-methylpyridinium based ionic liquids in aqueous solution: Viscometry, conductometry, UV-Vis spectroscopy and density functional theory studies was written by Mehrdad, Abbas;Parvini, Elahe. And the article was included in Journal of Chemical Thermodynamics in 2019.SDS of cas: 65350-59-6 This article mentions the following:

Viscosity (η) and molar conductivity (δ) of aqueous solutions of sodium polystyrene sulfonate (NaPSS) in the presence of some 4-methylpyridinium based ionic liquids (1-Butyl-4-methylpyridinium bromide [BMPyr]Br, 1-Hexyl-4-methylpyridinium bromide [HMPyr]Br and 1-Octyl-4-methylpyridinium bromide [OMPyr]Br) were investigated at T = (288.15, 298.15 and 308.15) K. The viscosity values were correlated with the Wolf equation to obtain the intrinsic viscosity ([η]) of NaPSS. The intrinsic viscosity of NaPSS decreases by increasing the concentration of ionic liquids due to screens effects of ionic liquids and decreased with increasing alkyl chain length of ILs. The scaling theory is used for the description of elec. conductance of polyelectrolytes. The values of fractions of uncondensed counterions f have been estimated The effects of the polyelectrolyte concentration, the relative permittivity of the medium, different alkyl chain length and the temperature on the fractions of uncondensed counterions of NaPSS aqueous solutions have been discussed. UV-Vis spectroscopy and Quantum chem. calculations studies are also used to confirm the existence of interactions between NaPSS and ILs. The UV-Vis spectra of NaPSS show that the conformation of NaPSS changes in the presence of ionic liquids; therefore the value of elec. multipole moment decreases. Consequently, the absorption intensity of NaPSS was decreased with the addition of ionic liquids D. functional theory (DFT) has been used to investigate the interactions between [PSS]^– anion and [RMPyr]⁺ cations. The mol. electrostatic potential, natural bond orbital methodologies and atoms in mols. are used to analyses the nature of interactions of the ion-pairs [RMPyr]⁺[PSS]^–. In the experiment, the researchers used many compounds, for example, 1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6SDS of cas: 65350-59-6).

1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. 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. SDS of cas: 65350-59-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Original synthesis of radiolabeling precursors for batch and on resin one-step/late-stage radiofluorination of peptides was written by Richard, Mylene;Specklin, Simon;Roche, Melanie;Hinnen, Francoise;Kuhnast, Bertrand. And the article was included in Chemical Communications (Cambridge, United Kingdom).Reference of 3939-12-6 This article mentions the following:

Radiolabeling of peptides with fluorine-18 is hurdled by their chem. sensitivity and complicated processes. Original triflyl-pyridine intermediates afforded ammonium precursors that were radiolabeled at low temperature From that study, a generic tag has been designed to allow a simple one-step/late-stage radiolabelling of peptides. The strategy has been transposed to an automated “on-resin” radiolabelling. In the experiment, the researchers used many compounds, for example, 6-Fluoronicotinonitrile (cas: 3939-12-6Reference of 3939-12-6).

6-Fluoronicotinonitrile (cas: 3939-12-6) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. 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.Reference of 3939-12-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Versatile and robust C-C activation by chelation-assisted manganese catalysis was written by Wang, Hui;Choi, Isaac;Rogge, Torben;Kaplaneris, Nikolaos;Ackermann, Lutz. And the article was included in Nature Catalysis in 2018.Recommanded Product: 4373-61-9 This article mentions the following:

C-H activation has been recognized as an increasingly viable tool in mol. sciences, but organometallic C-C activation is scarce, and limited to precious and toxic metal catalysts. Herein, versatile C-C activations by a robust base-metal catalyst in water has been disclosed. Thus, an inexpensive manganese(I) catalyst enabled C-C functionalizations with excellent levels of chemo- and position-selectivities, setting the stage for versatile C-C allylations, C-C alkenylations and C-C alkylations in water. The manganese(I) catalyst outperformed commonly used copper, iron, palladium, rhodium and ruthenium complexes, and the C-C activations occurred on steroid and amino acid motifs. Detailed kinetic and computational studies provided strong support for a kinetically relevant C-C manganesation. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Recommanded Product: 4373-61-9).

2-(m-Tolyl)pyridine (cas: 4373-61-9) 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. 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.Recommanded Product: 4373-61-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Anionic Access to Silylated and Germylated Binuclear Heterocycles was written by Boddaert, Thomas;Francois, Cyril;Mistico, Laetitia;Querolle, Olivier;Meerpoel, Lieven;Angibaud, Patrick;Durandetti, Muriel;Maddaluno, Jacques. And the article was included in Chemistry – A European Journal in 2014.HPLC of Formula: 257937-08-9 This article mentions the following:

A simple access to silylated and germylated binuclear heterocycles, based on an original anionic rearrangement, is described. A set of electron-rich and electron-poor silylated aromatic and heteroaromatic substrates were tested to understand the mechanism and the factors controlling this rearrangement, in particular its regioselectivity. This parameter was shown to follow the rules proposed before from a few examples. Then, the effect of the substituents borne by the silicon itself, in particular the selectivity of the ligand transfer, was studied. Addnl., this chem. was extended to germylated substrates. A hypervalent germanium species, comparable to the putative intermediate proposed with silicon, seems to be involved. However, a pathway implicating the elimination of LiCH₂Cl was observed for the first time with this element, leading to unexpected products of the benzo-oxa (or benzo-aza) germol-type. In the experiment, the researchers used many compounds, for example, tert-Butyl (3-bromopyridin-4-yl)carbamate (cas: 257937-08-9HPLC of Formula: 257937-08-9).

tert-Butyl (3-bromopyridin-4-yl)carbamate (cas: 257937-08-9) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. 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.HPLC of Formula: 257937-08-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Nucleophilic aromatic substitution by [¹⁸F]fluoride at substituted 2-nitropyridines was written by Malik, Noeen;Solbach, Christoph;Voelter, Wolfgang;Machulla, Hans-Juergen. And the article was included in Journal of Radioanalytical and Nuclear Chemistry in 2010.Quality Control of 3-Hydroxy-6-methyl-2-nitropyridine This article mentions the following:

For the radiofluorination of benzenes and benzene derivatives, the electrophilic reaction with [¹⁸F]F₂ is a very common route. Yet, aromatic nucleophilic substitution (S_NAr) by n.c.a [¹⁸F]fluoride, which can be produced efficiently in high amounts, has been considered to be very desirable. However, to facilitate ¹⁸F-labeling via S_NAr at an electron rich aromatic system, an appropriate leaving group must be present together with an auxiliary group in ortho or para position to the leaving group. An interesting alternative for the auxiliary group is the heteroatom of a heteroaromatic system, for which pyridine is a leading example. Dolci et al. (J Label Compd Radiopharm 42:975-985, 1999) have evaluated the scope of the nucleophilic aromatic fluorination of 2-substituted pyridine rings using the activated K [¹⁸F]F-K₂₂₂ complex. As Me and methoxy groups are known to enhance the electron d. of an aromatic system by the +I and the +M effect, resp., S_NAr is unlikely to occur. Until now, the effect of these substituents has not been studied towards the ¹⁸F-radiofluorination of substituted 2-nitropyridines by use of [¹⁸F]fluoride. Therefore, we have investigated the effect of methoxy and Me groups in 2-nitropyridines. The results showed that 3-methoxy-2-nitropyridine and 3-methyl-2-nitropyridine can efficiently be substituted by [¹⁸F]fluoride with high RCY’s (70-89%) in short reaction times (1-30 min) at a reaction temperature of 140 °C. Moreover, 3-methoxy-6-methyl-2-[¹⁸F]fluoropyridine was obtained from the corresponding nitro-precursor in a high yield of 81 ± 1% after 30 min at 140 °C. In case of 2-nitropyridines data indicates the effect of Me and methoxy groups on S_NAr to be of minor importance. In the experiment, the researchers used many compounds, for example, 3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2Quality Control of 3-Hydroxy-6-methyl-2-nitropyridine).

3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2) 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. 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. Quality Control of 3-Hydroxy-6-methyl-2-nitropyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Direct ortho-C-H Aminoalkylation of 2-Substituted Pyridine Derivatives Catalyzed by Yttrium Complexes with N,N’-Diarylethylenediamido Ligands was written by Kundu, Abhinanda;Inoue, Mariko;Nagae, Haruki;Tsurugi, Hayato;Mashima, Kazushi. And the article was included in Journal of the American Chemical Society in 2018.HPLC of Formula: 644-98-4 This article mentions the following:

A mixed ligated amidoyttrium complex, Y(NBn₂)(L1)(THF)₂ (L1 = N,N’-bis(2,6-diisopropylphenyl)ethylenediamine), served as a catalyst for addition of the ortho-pyridyl C(sp²)-H bond of 2-substituted pyridines to nonactivated imines; and showed superior catalytic performance compared with Y[N(SiMe₃)₂]₃ and Y[N(SiMe₃)₂]₂(NBn₂)(THF). Concerning the reaction mechanism, a stoichiometric reaction of an alkylyttrium complex, Y(CH₂SiMe₃)(L1)(THF)₂, with 2-ethylpyridine, giving a mixture of (η³-pyridylmethyl)yttrium complex and (η²-pyridyl)yttrium complex along with elimination of SiMe₄. Furthermore, addition of N-(tert-butyl)-2-methylpropan-1-imine to the mixture of yttrium complexes afforded a (pyridylmethylamido)yttrium complex as a single product, and the catalytic activity of the pyridinyl-yttrium complex was comparable to that of Y(NBn₂)(L1)(THF)₂ complex. Kinetic anal. of the aminoalkylation reaction in the presence/absence of HNBn₂ revealed that the reaction rate in the presence of HNBn₂ was four times faster than that without HNBn₂ due to acceleration of the product-eliminating step from the complex by HNBn₂ to regenerate amidoyttrium complex and the product. In addition, it was determined that the catalytic reaction obeyed a first-order rate dependence on the catalyst concentration, independent of the imine concentration, and a second-order rate dependence on the concentration of the pyridine substrate in the reaction system, both with and without HNBn₂. An enantiomerically pure N,N’-diaryl-1,2-diphenylethylenediamido ligand was applied for the C(sp²)-H aminoalkylation reaction in combination with Lu(CH₂SiMe₃)₃(THF)₂ to give chiral aminoalkylated products in moderate yield with good enantioselectivity. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4HPLC of Formula: 644-98-4).

2-Isopropylpyridine (cas: 644-98-4) belongs to pyridine derivatives. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. 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. HPLC of Formula: 644-98-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem