Day: January 5, 2023

A general N-alkylation platform via copper metallaphotoredox and silyl radical activation of alkyl halides was written by Dow, Nathan W.;Cabre, Albert;MacMillan, David W. C.. And the article was included in Chem in 2021.Safety of tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate This article mentions the following:

The catalytic union of amides, sulfonamides, anilines, imines, or N-heterocycles with a broad spectrum of electronically and sterically diverse alkyl bromides has been achieved via a visible-light-induced metallaphotoredox platform. The use of a halogen abstraction-radical capture (HARC) mechanism allows for room temperature coupling of C(sp³)-bromides using simple Cu(II) salts, effectively bypassing the prohibitively high barriers typically associated with thermally induced SN² or SN¹ N-alkylation. This regio- and chemoselective protocol is compatible with >10 classes of medicinally relevant N-nucleophiles, including established pharmaceutical agents, in addition to structurally diverse primary, secondary, and tertiary alkyl bromides. Furthermore, the capacity of HARC methodologies to engage conventionally inert coupling partners is highlighted via the union of N-nucleophiles with cyclopropyl bromides and unactivated alkyl chlorides, substrates that are incompatible with nucleophilic substitution pathways. Preliminary mechanistic experiments validate the dual catalytic, open-shell nature of this platform, which enables reactivity previously unattainable in traditional halide-based N-alkylation systems. In the experiment, the researchers used many compounds, for example, tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (cas: 85838-94-4Safety of tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate).

tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (cas: 85838-94-4) 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 groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Safety of tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis and Characterization of Poly(m-tolyloxy-co-4-pyridinoxy phosphazene)s and their Application as Proton Exchange Membranes was written by Yigen, Burak;Kassim Ali, Mariamu;Karatas, Betul;Alkan Guersel, Selmiye;Karatas, Yunus. And the article was included in ChemistrySelect in 2022.COA of Formula: C5H5NO This article mentions the following:

A novel set of polyphosphazenes are synthesized to produce three polymers with varying side group ratios for proton exchange membranes. The designed heterosubstituted polymers here are the rare examples of polyphosphazenes of this kind to serve as proton exchange membranes with optimized structural stability and high temperature ionic conductivity High quality polyphosphazenes with narrow polydispersity and rather low Tg values were prepared These poly(m-tolyloxy-co-4-pyridinoxy phosphazene)s are sulfonated under a range of conditions and characterized in order to investigate the synergetic effect of the heteroatom on the proton conductivity of the proton exchange membranes. The effect of sulfonation temperature and time on the fuel cell relevant properties is also investigated. Hydrolytically stable proton exchange membranes with high thermal and chem. stabilities are achieved. Addnl., resultant membranes exhibit proton conductivity, IEC and water uptake values comparable with com. Nafion membranes. In the experiment, the researchers used many compounds, for example, Pyridin-4-ol (cas: 626-64-2COA of Formula: C5H5NO).

Pyridin-4-ol (cas: 626-64-2) 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. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. COA of Formula: C5H5NO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Triple Hydrogen Bonding for Stereospecific Radical Polymerization of a DAD Monomer and Simultaneous Control of Tacticity and Molecular Weight was written by Wan, Decheng;Satoh, Kotaro;Kamigaito, Masami. And the article was included in Macromolecules in 2006.Synthetic Route of C7H9N3O This article mentions the following:

A triple hydrogen bonding interaction effectively controlled the stereochem. during radical polymerization of acrylamide derivatives An acrylamide monomer, in which amide (proton donor site, D) and pyridine (proton acceptor site, A) moieties were arrayed in the DAD sequence, was polymerized in the presence of a cyclic imide as the ADA-type receptor in CHCl₃ to give syndiotactic polymers (r = 72%) even at 60 °C while atactic polymers (r = 43%) were obtained without the mediator. Furthermore, the simultaneous control of the tacticity and the mol. weights of the polymers were attained by RAFT polymerization in the presence of the mediator. In the experiment, the researchers used many compounds, for example, N-(6-Aminopyridin-2-yl)acetamide (cas: 1075-62-3Synthetic Route of C7H9N3O).

N-(6-Aminopyridin-2-yl)acetamide (cas: 1075-62-3) 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. 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.Synthetic Route of C7H9N3O

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Regio- and Stereoselective Alkylation of Pyridine-N-oxides: Synthesis of Substituted Piperidines and Pyridines was written by Barange, Deepak Kumar;Johnson, Magnus T.;Cairns, Andrew G.;Olsson, Roger;Almqvist, Fredrik. And the article was included in Organic Letters in 2016.Application of 3718-65-8 This article mentions the following:

Regio- and stereoselective addition of alkyl Grignard reagents to pyridine-N-oxides gave C2-alkylated N-hydroxy-1,2,5,6-tetrahydropyridines and trans-2,3-disubstituted N-hydroxy-1,2,5,6-tetrahydropyridines in good to excellent yields. These intermediates were aromatized or alternatively reduced in one-pot methodologies for efficient syntheses of alkylpyridines or piperidines, resp. These reactions have a broad substrate scope and short reaction times. The methodol. allows an efficient synthesis of racemic coniine, a toxic alkaloid found in hemlock (Conium maculactum). In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Application of 3718-65-8).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) 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. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Application of 3718-65-8

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Copper(II)-Promoted Mono-Selective ortho C-H Chlorination of Arenes by Using Trimethyl(trichloromethyl)silane was written by Zhu, Zhaobin;Xu, Changming;Wang, Yongchang;Zhao, Li. And the article was included in Synlett in 2018.Name: 2-(m-Tolyl)pyridine This article mentions the following:

The first example of a Cu-promoted ortho-chlorination of aryl C-H bonds by using TMSCCl₃as chlorinating agent is reported. This reaction features a high selectivity toward monochlorination over dichlorination, compatibility with a variety of functional groups, and gram-scale synthesis. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Name: 2-(m-Tolyl)pyridine).

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. Pyridine derivatives are also useful as small-molecule α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Name: 2-(m-Tolyl)pyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Application of the coagulation titration method for quantitative determination of the content of anion-active emulsifiers in latex was written by Poyarkova, T. N.;Sotnikova, E. V.;Kudrina, G. V.. And the article was included in Russian Journal of Applied Chemistry in 2013.Computed Properties of C17H30BrN This article mentions the following:

Fast quant. determination of the content of emulsifiers of the alkyl sulfate type in latexes by their titration in a strongly diluted (1: 10⁴) state with a solution of a cation-active surfactant (cetylpyridinium chloride) was achieved. The titration end point was determined as the abscissa of the point of a maximum (cm) in the curve describing the dependence of the “minute turbidity” of the latex on the cetylpyridinium chloride concentration The effect of the alkyl chain length of the cation-active surfactant on the value of cm at the titration end point was studied. In the experiment, the researchers used many compounds, for example, 1-Dodecylpyridin-1-ium bromide (cas: 104-73-4Computed Properties of C17H30BrN).

1-Dodecylpyridin-1-ium bromide (cas: 104-73-4) 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.Computed Properties of C17H30BrN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Ionic liquids as reaction medium in cellulose functionalization was written by Heinze, Thomas;Schwikal, Katrin;Barthel, Susann. And the article was included in Macromolecular Bioscience in 2005.Recommanded Product: 1-Butyl-3-methylpyridinium Chloride This article mentions the following:

The application of different ionic liquids (IL), namely 1-N-butyl-3-methylimidazolium chloride ([C₄mim]⁺Cl^–), 3-methyl-N-butyl-pyridinium chloride and benzyldimethyl(tetradecyl)ammonium chloride were investigated as solvents for cellulose. The ILs used have the ability to dissolve cellulose with a d.p. in the range from 290 to 1200 to a very high concentration Using [C₄mim]⁺Cl^–, no degradation of the polymer appears. By ¹³C NMR measurement it was confirmed that this IL is a so called non-derivatizing solvent. [C₄mim]⁺Cl^– can be applied as a reaction medium for the synthesis of CM-cellulose and cellulose acetate. Without using any catalyst, cellulose derivatives with high degree of substitution could be prepared In the experiment, the researchers used many compounds, for example, 1-Butyl-3-methylpyridinium Chloride (cas: 125652-55-3Recommanded Product: 1-Butyl-3-methylpyridinium Chloride).

1-Butyl-3-methylpyridinium Chloride (cas: 125652-55-3) 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. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Recommanded Product: 1-Butyl-3-methylpyridinium Chloride

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Antifungal characteristics of N,N’-hexamethylenebis (4-carbamoyl-1-decylpyridinium bromide) was written by Okazaki, Kiyo;Yoshida, Munehiro;Mayama, Mari;Shirai, Akihiro;Maeda, Takuya;Nagamune, Hideaki;Kourai, Hiroki. And the article was included in Biocontrol Science in 2006.Application In Synthesis of 1-Dodecylpyridin-1-ium bromide This article mentions the following:

A bis-quaternary ammonium compound (bis-QAC), N,N’-hexamethylenebis(4-carbamoyl-1-decylpyridinium bromide) (D-38), exhibited a wide antifungal spectrum and a strong activity against sixteen strains of fungi including nine strains isolated from various kinds of food. The antifungal activity was higher than that of N-dodecylpyridinium iodide, a typical mono-QAC, and that of the commonly used fungicide, 2-(4-thiazolyl) benzimidazole. The activity of D-38, however, was comparatively low when it was measured by the agar dilution method. It is considered that the hydrophobic D-38 mols., having two long alkyl chains, interacted with the agar medium, and therefore showed lower activity results. On the other hand, the activity of D-38 against Aspergillus niger IFO 6342 was not significantly influenced by temperature, pH and the initial spore concentration These results indicate that bis-QACs can exhibit a high antifungal activity whether or not the environmental conditions change. In the experiment, the researchers used many compounds, for example, 1-Dodecylpyridin-1-ium bromide (cas: 104-73-4Application In Synthesis of 1-Dodecylpyridin-1-ium bromide).

1-Dodecylpyridin-1-ium bromide (cas: 104-73-4) 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 groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Application In Synthesis of 1-Dodecylpyridin-1-ium bromide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Nitropyridyl isocyanates in 1,3-dipolar cycloaddition reactions was written by Holt, Jarle;Fiksdahl, Anne. And the article was included in Journal of Heterocyclic Chemistry in 2007.Name: 3,5-Dimethylpyridine 1-oxide This article mentions the following:

The reactivity of 3-nitropyridin-4-yl isocyanate (I) and 5-nitropyridin-2-yl isocyanate (II) in 1,3-dipolar cycloaddition reactions with azides and pyridine N-oxides was investigated. 1,3-Dipolar cycloaddition to Me₃SiN₃ (TMSA) afforded tetrazolinones, 1-(3-nitropyridin-4-yl)- and 1-(5-nitropyridin-2-yl)-1H-tetrazol-5(4H)one in 50 and 64% yield, resp. Resp., 1,3-dipolar cycloaddition of I and II to 3,5-dimethylpyridine N-oxide, 3-methylpyridine N-oxide, and pyridine N-oxide gave the substituted amines, 3,5-dimethyl-N-(3-nitropyridin-4-yl)pyridin-2-amine, 3,5-dimethyl-N-(5-nitropyridin-2-yl)pyridin-2-amine, N-(5-nitropyridin-2-yl)pyridin-2-amine, 5-methyl-N-(5-nitropyridin-2-yl)pyridin-2-amine, and 3-methyl-N-(5-nitropyridin-2-yl)pyridin-2-amine in 65-80% yield, obtained by cycloaddition, rearrangement, and decarboxylation. The results demonstrate that the nitropyridyl isocyanates readily undergo 1,3-dipolar cycloaddition reactions similar to Ph isocyanates. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Name: 3,5-Dimethylpyridine 1-oxide).

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. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Name: 3,5-Dimethylpyridine 1-oxide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Cyanation of amine oxide salts. A new synthesis of cyanopyridines was written by Feely, Wayne E.;Beavers, Ellington M.. And the article was included in Journal of the American Chemical Society in 1959.Safety of 4-Methylpicolinonitrile This article mentions the following:

In general, pyridines, quinolines, and isoquinoline oxidized with 30% H₂O₂ in AcOH according to Ochiai (C.A. 48, 3359i) gave the corresponding amine oxides, which without purification, treated slowly at room temperature with an equimolar quantity of Me₂SO₄ and the mixture heated 2 hrs. on a steam bath gave the N-OMe MeSO₄^– salts (for example, 1-methoxy-2-methylpyridinium methyl sulfate, m. 57-60°, and its 6-Me derivative, m. 95-7°), and these without purification added in aqueous solution to KCN in H₂O gave the cyano derivatives, isolated by filtration (F), distillation (D), recrystallization (R), steam distillation (SD), or extraction with CHCl₃ (E) (product, m.p., % yield, method of isolation, m.p. of picrate given): 4-NCC₅H₄N (I), 80-2°, 32, E or D or R, 200-3°; 2-NCC₅H₄N (II), 22-5°, 49, -, -; 2,6-NCC₅H₃NMe, 71-3°, 48, F or R, 105-8°; 4,2-NCC₅H₃NMe, 46-8°, 10, -, -; 2,4-NCC₅H₃NMe, 89-91°, 40, F or R, 100-2°; 2,3-NCC₅H₃NMe, 87-90°, 36, F or R, 93-5°; 2,5-NCC₅H₃NMe, 73-5°, 6, -, -; 4,3-NCC₅H₃NMe, 51-2°, 6, -, -; 2,4,6-NCC₅H₂NMe₂, 55-6°, 73, E or D, 100-2°; 4,2,6-NCC₅H₂NMe₂, 77-81°, 40, F or E or D, 178-81°; 2,4-(NC)₂C₅H₃N, 88-91°, 54, F or R, -; 2-cyanoquinoline, 94-6°, 93, F or R, -; 2-cyano-4-methylquinoline, 96-8°, 65, F or R, -; 4-cyano-2-methylquinoline, 105-6°, 7.2, SD, -; 1-cyanoisoquinoline, 92-3°, 95, F or R, -. Three methods are described for the preparation of I. C₅H₅N(O) (III) (0.25 mole) refluxed 12 hrs. with 0.25 mole C₉H₁₉I in 200 ml. MeCN and the mixture then cooled in ice yielded 55% (C₅H₅NOC₉H₁₉)I, yellow needles, m. 87-90°. This (0.1 mole) added slowly to 0.3 mole KCN in 150 ml. H₂O, the oily product extracted with ether, and the ether solution extracted with 10% HCl yielded from the ether layer 75% C₉H₁₉OH, b. 210-15°, n²⁰_D 1.4328; phenylurethan m. 62.5-3.5°. The aqueous acid layer neutralized with Na₂CO₃ and extracted with ether yielded 42% I; HCl salt m. 244-7° (decomposition). Also III (0.5 mole) similarly refluxed with 0.2 mole I(CH₂)₁₀I gave [C₅H₅NO(CH₂)₁₀ONC₅H₅]2I, m. 118-20° (decomposition), and this similarly treated with KCN gave a solid instead of an oil, filtered without ether extraction, 82% HO(CH₂)₁₀OH, m. 72-4° (diacetate m. 23-6); from the filtrate was extracted with ether 37% I. Also (C₅H₅NOMe)MeSO₄ (0.5 mole) in 125 ml. H₂O added during 1 hr to 1.5 mole NaCN in 250 ml. H₂O at -5°, the mixture kept 1 addnl. hr. at -5°, stirred 3 hrs. at 20°, extracted with CHCl₃, and the residue from the extract distilled yielded 16% I, b. 208-12°, and 49% II, b. 220-5°. The mechanism of the general reaction of CN^– with such N-methoxy quaternary salts was discussed, in which the intermediate N-methoxy dihydro compound lost H⁺ and OMe^– to reform the aromatic system. In the experiment, the researchers used many compounds, for example, 4-Methylpicolinonitrile (cas: 1620-76-4Safety of 4-Methylpicolinonitrile).

4-Methylpicolinonitrile (cas: 1620-76-4) 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. 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.Safety of 4-Methylpicolinonitrile

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem