Month: December 2022

Oxygen-17 NMR spectroscopy: σ_I dependence for the substituent chemical shifts of 3-substituted pyridine 1-oxides was written by Sawada, Masami;Takai, Yoshio;Kimura, Satoshi;Yamano, Satoshi;Misumi, Soichi;Hanafusa, Terukiyo;Tsuno, Yuho. And the article was included in Tetrahedron Letters in 1986.Application In Synthesis of 3,5-Dimethylpyridine 1-oxide This article mentions the following:

¹⁷O NMR spectra were measured at natural abundance in DMSO for a series of 3-substituted pyridine 1-oxides, and their substituent chem. shifts were correlated with σ_I substituent constants and not with ΔpK_a values. 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. 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, 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. Application In Synthesis of 3,5-Dimethylpyridine 1-oxide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Triazolopyridines. 18. Nucleophilic substitution reactions of triazolopyridines; a new route to 2,2′-bipyridines was written by Jones, Gurnos;Pitman, Mark A.;Lunt, Edward;Lythgoe, David J.;Abarca, Belen;Ballesteros, Rafael;Elmasnaouy, Mostafa. And the article was included in Tetrahedron in 1997.Computed Properties of C6H6BrNO This article mentions the following:

The synthesis of some 5-, 6-, and 7-halotriazolopyridines and their reactions with nucleophiles are described. The formation of 7,7′-bitriazolopyridines provides a new synthesis of 2,2′-bipyridines. In the experiment, the researchers used many compounds, for example, (4-Bromopyridin-2-yl)methanol (cas: 131747-45-0Computed Properties of C6H6BrNO).

(4-Bromopyridin-2-yl)methanol (cas: 131747-45-0) 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. 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.Computed Properties of C6H6BrNO

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Room temperature Ru(III)-catalyzed ortho-hydroxymethylation of arenes was written by Zhang, Yong;Yang, Zhongzhen;Yu, Xinling;Cheng, Xu;Li, Weijian;Guo, Lingmei;Hai, Li;Guo, Li;Wu, Yong. And the article was included in Youji Huaxue in 2018.Computed Properties of C12H11N This article mentions the following:

Direct synthesis of the hydroxymethylated arene derivatives via ruthenium(III)-catalyzed nitrogen atom directed C-H activation is described. The reaction proceeds smoothly at room temperature and generates the corresponding products in moderate to excellent yields. Meanwhile, it has a broad substrate scope and opens up an attractive avenue for the application of direct hydroxymethylation in the synthesis of biol. active compounds 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’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, 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. Computed Properties of C12H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Selective C-H Bond Fluorination of Phenols with a Removable Directing Group: Late-Stage Fluorination of 2-Phenoxyl Nicotinate Derivatives was written by Lou, Shao-Jie;Chen, Qi;Wang, Yi-Feng;Xu, Dan-Qian;Du, Xiao-Hua;He, Jiang-Qi;Mao, Yang-Jie;Xu, Zhen-Yuan. And the article was included in ACS Catalysis in 2015.SDS of cas: 4783-68-0 This article mentions the following:

A facile and site-selective C-H bond fluorination of phenols using removable 2-pyridyloxy group as an auxiliary was developed. E.g., in presence of Pd(dba)₂ and N-fluorobenzenesulfonimide, fluorination of 2-phenoxypyridine gave 81% I. Alternatively, late-stage C-H bond fluorination of bioactive 2-phenoxyl nicotinate derivatives and diflufenican were also feasible under the present strategy. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0SDS of cas: 4783-68-0).

2-Phenoxypyridine (cas: 4783-68-0) 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.SDS of cas: 4783-68-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Smart Shell-by-Shell Nanoparticles with Tunable Perylene Fluorescence in the Organic Interlayer was written by Stiegler, Lisa M. S.;Klein, Stefanie;Kryschi, Carola;Neuhuber, Winfried;Hirsch, Andreas. And the article was included in Chemistry – A European Journal in 2021.Quality Control of 1-Dodecylpyridin-1-ium bromide This article mentions the following:

A new series of shell-by-shell (SbS)-functionalized Al₂O₃ nanoparticles (NPs) containing a perylene core in the organic interlayer as a fluorescence marker is introduced. Initially, the NPs were functionalized with both, a fluorescent perylene phosphonic acid derivative, together with the lipophilic hexadecylphosphonic acid or the fluorophilic (1 H,1 H,2 H,2H-perfluorodecyl)phosphonic acid. The lipophilic first-shell functionalized NPs were further implemented with amphiphiles built of aliphatic chains and polar head-groups. However, the fluorophilic NPs were combined with amphiphiles consisting of fluorocarbon tails and polar head-groups. Depending on the nature of the combined phosphonic acids and the amphiphiles, tuning of the perylene fluorescence can be accomplished due variations of supramol. organization with the shell interface. Because the SbS-functionalized NPs dispose excellent dispersibility in water and in biol. media, two sorts of NPs with different surface properties were tested with respect to biol. fluorescent imaging applications. Depending on the agglomeration of the NPs, the cellular uptake differs. The uptake of larger agglomerates is facilitated by endocytosis, whereas individualized NPs cross directly the cellular membrane. Also, the larger agglomerates were preferentially incorporated by all tested cells. In the experiment, the researchers used many compounds, for example, 1-Dodecylpyridin-1-ium bromide (cas: 104-73-4Quality Control of 1-Dodecylpyridin-1-ium bromide).

1-Dodecylpyridin-1-ium bromide (cas: 104-73-4) 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.Quality Control of 1-Dodecylpyridin-1-ium bromide

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Dimerization of 2-pyridylisonitriles produces π-extended fused heteroarenes useful as highly selective colorimetric and optical probes for copper ion was written by Shao, Na;Pang, Guang-Xian;Wang, Xiao-Rong;Wu, Rui-Juan;Cheng, Ying. And the article was included in Tetrahedron in 2010.Synthetic Route of C7H6N2 This article mentions the following:

A very simple synthesis of pyrido[2”,1”:2′,3′]imidazo[4′,5′:4,5]imidazo[1,2-a]pyridines (I) was achieved from the dimerization of 2-pyridylisonitriles. The optical responses of these π-extended fused heteroarenes to metal ions were studied by UV-visible absorption spectrum in acetonitrile. Most of compounds I selectively responded to Cu²⁺, and the limit of detection was ∼3.5 × 10^-7 M when using the best probe, 3,9-dimethylpyrido[2”,1”:2′,3′]imidazo[4′,5′:4,5]imidazo[1,2-a]pyridine (I, X = 4-Me). Meanwhile some compounds I specifically showed a color change from colorless to red or yellow when they are exposed to copper ion in acetonitrile, whereas other transition, alkali and alk. earth metal ions could not induce a color change. This work not only established a direct access to π-extended fused heteroarenes, but also supplied novel sensitive and selective colorimetric and optical probes for copper ion. In the experiment, the researchers used many compounds, for example, 4-Methylpicolinonitrile (cas: 1620-76-4Synthetic Route of C7H6N2).

4-Methylpicolinonitrile (cas: 1620-76-4) 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. 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 C7H6N2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Preparation of 2-cyanopyridines from cyanogen and some simple 1,3-dienes was written by Janz, G. J.;Keenan, A. G.. And the article was included in Canadian Journal of Research, Section B: Chemical Sciences in 1947.Recommanded Product: 4-Methylpicolinonitrile This article mentions the following:

The Diels-Alder type of mechanism was assumed in the reaction of C₂N₂ (I) and 1,3-dienes, with spontaneous dehydrogenation of the adduct to form substituted 2-cyano-pyridines. Isoprene and 1 mol. I were fed into a vapor-phase reactor at 490° and 90 sec. contact time at the rate of 21.4 and 15.9 g./hr., resp.; a black pasty solid was formed at 13.5 g./hr. 2-Cyano-4-picoline (II), obtained from the crude product in 18% impure yield, b₂ 88.5°, m. 48-77° (ligroin). II with boiling aqueous NaOH, then dry distillation with CaO, gave a fraction b. 143-8° (known mixture of 3- and 4-picolines b. 142-6°). Separation of the ZnCl₂ salts (cf. C.A. 24, 2461) and treatment with KOH gave a colorless oil; picrate m. 161-2° (from EtOH); authentic 4-picoline picrate m. 163.5-4.5°; x-ray diffraction patterns were identical. Another mixture of picolines prepared from crude II b. 142-5°; separation as the oxalates (cf. C.A. 34, 2846.1; 35, 2146.3) gave a product m. 137.5-9°, corresponding to 4-picoline oxalate. No 3-picoline derivatives were found. 2-Chloro-1,3-butadiene (III) and 1 mol. I were fed into the vapor-phase reactor at 500° and 110 sec. contact time at 20 and 12 g. per hr., resp., and a crude product formed at 9 g. per hr. The total recovery of products and unchanged I and III was 63%. The product contained 15% of a chlorocyanopyridine, b₃₀ 140°, m. 107.5-8° (from Et₂O-EtOH). The black tarry residue in the reactor contained 5-chloro-2-cyanopyridine, m. 83-4° (from EtOH); 75% alc. NaOH gave 5-chloropicolinic acid, m. 172°. 2-Methyl-1,3-pentadiene and 1 mol. I were fed into the vapor-phase reactor at 500° and 121 sec. contact time at rates of 13.2 and 17 g./hr., resp., to form 61% crude product. 6-Cyano-2,4-lutidine, obtained in 30% yield from the crude product, m. 53-3.5° (from ligroin). Aqueous NaOH and dry distillation with CaO gave 2,4-lutidine, b₇₆₀ 156-7°; picrate m. 179-80° (from EtOH). Hexachloro-1,3-butadiene (IV), (CCl:CCl₂)₂, and 1 mol. I at 150-70° 46 hrs. gave only a slight reaction; 86% IV was recovered. Similar results were obtained at 210° and 37 hrs. and 230° and 66 hrs. Failure of IV to react with I is consistent with previous work on CCl:C.C:C and C:CCl.CCl:C structures. In the experiment, the researchers used many compounds, for example, 4-Methylpicolinonitrile (cas: 1620-76-4Recommanded Product: 4-Methylpicolinonitrile).

4-Methylpicolinonitrile (cas: 1620-76-4) 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.Recommanded Product: 4-Methylpicolinonitrile

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

End-of-Life Treatment of Poly(Vinyl Chloride) and Chlorinated Polyethylene by Dehydrochlorination in Ionic Liquids was written by Glas, Daan;Hulsbosch, Joris;Dubois, Philippe;Binnemans, Koen;De Vos, Dirk E.. And the article was included in ChemSusChem in 2014.SDS of cas: 125652-55-3 This article mentions the following:

There is an urgent need for green technologies to remove halogens from halogenated polymers at the end of their lifetime. Ionic liquids (ILs) were used to dehydrochlorinate and/or dissolve the chlorinated polymers poly(vinyl chloride) (PVC) and chlorinated polyethylene (CPE). The dehydrochlorination activity of an IL depends mainly on its anion and is related to the high hydrogen-bond-accepting ability (β value) of the anion. Different phosphonium ILs successfully dissolve and dehydrochlorinate PVC and CPE at temperatures from 80 °C. PVC is dehydrochlorinated up to 98 % after 60 min in tetrabutylphosphonium chloride ([P₄₄₄₄][Cl]) at 180 °C. PVC pieces stabilized by calcium stearate (4 mm³) are dehydrochlorinated more slowly; conversions of 85 and 96 % are reached after 1 and 8 h, resp. Smaller pieces are dehydrochlorinated faster. High loadings, for example, 0.3 g stabilized PVC in 0.5 g IL, can be applied with only a minor loss of conversion. [P₄₄₄₄][Cl] proved to be stable during several consecutive reactions; after each run more than 99 % of the IL can be recovered. The structure of the dehydrochlorinated PVC was studied by ¹³C cross-polarization magic-angle spinning NMR and FTIR spectroscopy; the removal of Cl and the formation of double bonds were confirmed. Carefully dehydrochlorinated CPE was processed further by acyclic diene metathesis depolymerization with ethylene and the Hoveyda-Grubbs second-generation catalyst to yield α,ω-dienes such as 1,5-hexadiene and 1,6-heptadiene. In the experiment, the researchers used many compounds, for example, 1-Butyl-3-methylpyridinium Chloride (cas: 125652-55-3SDS of cas: 125652-55-3).

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. 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.SDS of cas: 125652-55-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Optical properties of stilbene-type dyes containing various terminal donor and acceptor groups was written by Qin, Chuanxiang;Zhang, Weizhou;Wang, Zhiming;Zhou, Maoyi;Wang, Xiaomei;Chen, Guoqiang. And the article was included in Optical Materials (Amsterdam, Netherlands) in 2008.Recommanded Product: 65350-59-6 This article mentions the following:

A series of “D-π-A” stilbene-type dyes, named as trans-4-[p-(N,N-hydroxyethyl) aminino-styryl]-N-methylpyridinium iodide (DHEASPI-C₁), trans-4-[p-(N,N-hydroxyethyl) aminino-styryl]-N-butylpyridinium bromide (DHEASPBr-C₄), trans-4-[p-(N,N-hydroxyethyl) aminino-styryl]-N-octylpyridinium bromide (DHEASPBr-C₈) and trans-4-[p-(N,N-hydroxyethyl) aminino-styryl]-N-dodecylpyridinium bromide (DHEASPBr-C₁₂), resp., have been synthesized and their optical properties have been exptl. investigated. When DHEASPI-C₁ are compared with trans-4-[p-(N,N-diethylamino) styryl]-N-methylpyridinium iodide (DEASPI) and trans-4-[p-(N-hydroxyethyl-N-ethylamino) styryl]-N-methylpyridinium iodide (HEASPI), both the electronegativity of two hydroxyl and intra-mol. hydrogen bond decrease the donor ability of the Et chain, there are obvious blue shifts both in single-photon absorption spectra, fluorescence spectra and two-photon excited fluorescence spectra. Interestingly, fluorescence intensity of DHEASPI-C₁ is the biggest. There are little shifts from DHEASPBr-C₄ to DHEASPBr-C₈ and to DHEASPBr-C₁₂ in their spectra. As dyes’ two-photon excited fluorescence spectra were concerned, pumped by 1064 nm, <130 fs mode-locked Nd:YAG laser, their peak locations were between 613 and 623 nm. In the experiment, the researchers used many compounds, for example, 1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6Recommanded Product: 65350-59-6).

1-Butyl-4-methylpyridin-1-ium bromide (cas: 65350-59-6) 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). 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: 65350-59-6

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Effects of head group of cationic surfactants on the hydrolysis of p-nitrophenyl acetate catalyzed by α-chymotrypsin was written by Ghosh, Kallol K.;Verma, Santosh Kumar. And the article was included in International Journal of Chemical Kinetics in 2009.Synthetic Route of C17H30BrN This article mentions the following:

The search for activity enhancement (superactivity) has been an important aspect of in vitro micellar enzymol. The present kinetic study was undertaken to investigate the effect of different cationic surfactants which might improve the hydrolytic activity of chymotrypsin (I). Here, the kinetics of hydrolysis of p-nitrophenyl acetate catalyzed by I was studied in the presence of several cationic surfactants having different head groups maintaining the dodecyl hydrophobic residue and bromide counterion. I activity was tested in the presence of dodecyl trimethylammonium bromide (DTAB), dodecylpyridinium bromide (DPB), dodecyldimethylethanolammonium bromide (DDMEAB), dodecyldiethylethanolammonium bromide (DDEEAB), benzyldimethyldodecylammonium bromide (BDDAB), and dodecyltriphenylphosphonium bromide (DTPB) surfactants. The extent of superactivity depended upon the head groups of the surfactants. I activity also depended on the surfactant concentration and it varied with the surfactant head group dimensions (DTPB > DDEEAB > DTAB > BDDAB > DDMEAB > DPB). For all surfactants, DTPB exhibited the highest superactivity. The effects of the surfactants on apparent kinetic parameters such as the K_m and k_cat were determined In the experiment, the researchers used many compounds, for example, 1-Dodecylpyridin-1-ium bromide (cas: 104-73-4Synthetic Route of C17H30BrN).

1-Dodecylpyridin-1-ium bromide (cas: 104-73-4) 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. 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.Synthetic Route of C17H30BrN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem