Tag: 100-200

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

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

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

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

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

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

Iridium(III)-Catalyzed Direct Arylation of C-H Bonds with Diaryliodonium Salts was written by Gao, Pan;Guo, Wei;Xue, Jingjing;Zhao, Yue;Yuan, Yu;Xia, Yuanzhi;Shi, Zhuangzhi. And the article was included in Journal of the American Chemical Society in 2015.Formula: C8H11N This article mentions the following:

By developing a new Ir(III)-catalyzed C-C cross-coupling, a versatile method for direct arylation of sp² and sp³ C-H bonds in ketoximes, nitrogen-containing heterocycles, various arenes, and olefins has been established. The key to this arylation depends on the appropriate choice of catalyst and the use of diaryliodonium triflate salts as the coupling partners. This transformation has good functional group compatibility and can serve as a powerful synthetic tool for late-stage C-H arylation of complex compounds Mechanistic studies by d. functional theory calculations suggested that the sp³ C-H activation was realized by a triflate-involved concerted metalation-deprotonation process, and the following oxidation of Ir(III) to Ir(V) is the most favorable when a bistriflimide is contained in the diaryliodonium salt. Calculations indicated that both steps are enabled by initial anion exchange between the reactant complexes. 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 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, 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. Formula: C8H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Intermolecular, redox-neutral azidoarylation of alkenes via photoredox catalysis was written by Chen, Jian;Zhu, Shengqing;Qin, Jian;Chu, Lingling. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2019.Computed Properties of C6H3FN2 This article mentions the following:

An intermol., redox-neutral azidoarylation of alkenes with pyridines and TMSN₃ was reported via visible light-induced photoredox catalysis. This protocol utilized a radical addition/radical coupling sequence, allowing for facile and regioselective installation of versatile β-azido pyridines under redox-neutral and mild conditions. In the experiment, the researchers used many compounds, for example, 2-Fluoroisonicotinonitrile (cas: 3939-14-8Computed Properties of C6H3FN2).

2-Fluoroisonicotinonitrile (cas: 3939-14-8) 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.Computed Properties of C6H3FN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Rhodium-catalyzed ortho-heteroarylation of phenols: directing group-enabled switching of the electronic bias for heteroaromatic coupling partner was written by Wu, Yimin;Li, Wei;Jiang, Linfeng;Zhang, Luoqiang;Lan, Jingbo;You, Jingsong. And the article was included in Chemical Science in 2018.Reference of 4783-68-0 This article mentions the following:

A conception of directing group enabled-switching of the electronic bias for coupling partner from the electron-deficient to electron-rich heteroarene, demonstrating that the modification of the directing group may match the latent reactivity of heteroarene substrates caused by the distinctly different electronic nature was reported. A Rh(III)-catalyzed ortho-heteroarylation of phenols with greatly important electron-rich heteroarenes such as benzothiophene, benzofuran, thiophene, furan and pyrrole via two-fold C-H activation was developed, which presented broad substrate scopes of both phenols and electron-rich heteroarenes and showed the advantage of tolerance of reactive functional groups, especially halogen. This work also provided a new strategy for the construction of π-conjugated furan-fused heteroacenes prevalent in materials science in dramatically simplified procedures, which makes the protocol highly applicable. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Reference of 4783-68-0).

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

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Palladium catalyzed ligand-free Suzuki reaction in polyethylene glycol/H₂O was written by Li, Xin-min;Chen, Zheng-jun;Hu, Qing-hong;Zhang, Yu-ting;Wang, Zheng-qin;Yuan, Ze-li. And the article was included in Huaxue Shiji in 2018.SDS of cas: 4373-61-9 This article mentions the following:

In the presence of 0.3 mol% Pd(OAc)₂ and 70 mol% K₂CO₃, various hetero/aryl bromides could couple efficiently with aryl boronic acids in aqueous polyethylene glycol to afford biaryl products with excellent yields. This protocol shows tolerance to a diverse array of functionalized aryl bromides and boronic acids, and the highest biaryl product yield up to 98%. The absence of phosphine ligands and a large amount of base made the work-up process easier in this protocol. Moreover, this method allows the preparation of the core intermediate of valsartan in gram quantities with good yield. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9SDS of cas: 4373-61-9).

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. 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.SDS of cas: 4373-61-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem