Tag: 100-200

A Combined IM-MS/DFT Study on [Pd(MPAA)]-Catalyzed Enantioselective C-H Activation: Relay of Chirality through a Rigid Framework was written by Cheng, Gui-Juan;Chen, Ping;Sun, Tian-Yu;Zhang, Xinhao;Yu, Jin-Quan;Wu, Yun-Dong. And the article was included in Chemistry – A European Journal in 2015.Application In Synthesis of 2-Isopropylpyridine This article mentions the following:

A combined ion-mobility mass spectrometry (IM-MS) and DFT study has been employed to investigate the mechanism and the origin of selectivity of palladium/mono-N-protected amino acid (MPAA)-catalyzed enantioselective C-H activation reactions of several prochiral substrates. We captured the [Pd(MPAA)(substrate)] complex at different stages, and demonstrated that the C-H bond can be activated in the absence of an external base. DFT studies lead to the establishment of a significantly modified relay mechanism invoking a key conformational effect to account for the origin of enantioselectivity. This relay mechanism successfully accounts for the enantioselectivity for all the relevant reactions reported. The enantioselectivity originates from the rigid square-planar Pd coordination in the C-H activation transition state: Bidentate MPAA and substrate coordination. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4Application In Synthesis of 2-Isopropylpyridine).

2-Isopropylpyridine (cas: 644-98-4) 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. 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.Application In Synthesis of 2-Isopropylpyridine

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Downregulation of CYP1A2, CYP2B6, and CYP3A4 in human hepatocytes by prolyl hydroxylase domain 2 inhibitors via hypoxia-inducible factor-α stabilization was written by Takano, Hiroki;Yamaguchi, Jun-ichi;Kato, Sota;Hamada, Makoto;Tada, Mika;Endo, Hiromi. And the article was included in Drug Metabolism & Disposition in 2021.Quality Control of Methyl 6-Cyanopyridine-3-carboxylate This article mentions the following:

Hypoxia-inducible factor (HIF) is associated with the expression of CYP, but the underlying mechanism remains uncertain. In this study, we investigated the effect of HIF-α stabilization caused by novel prolyl hydroxylase domain (PHD) 2 inhibitors, which are HIF-α stabilizers that mimic hypoxia, on the expressions of CYP1A2, CYP2B6, and CYP3A4 in human hepatocytes. An mRNA expression anal. of human hepatocytes treated with PHD2 inhibitors for 72 h showed the downregulation of genes encoding CYP1A2, CYP2B6, and CYP3A4. The mRNA repressions were accompanied with an increase in erythropoietin protein, a marker of HIF-α stabilization, indicating that HIF-α stabilization was involved in the downregulation of the CYP isoforms. To understand the underlying mechanisms, we assessed the relationship between the expressions of the CYP isoforms and those of their regulating transcription factors [aryl hydrocarbon receptor (AhR), AhR nuclear translocator (ARNT), constitutive androstane receptor (CAR), pregnane X receptor (PXR), and retinoid X receptor (RXR)] in human hepatocytes treated with the HIF-α stabilizers. As a result, the mRNA level of AhR did not decrease, although ARNT expression was repressed. On the other hand, the mRNA expression levels of CAR, PXR, and RXR were repressed and closely associated with those of CYP2B6 and CYP3A4. Although the underlying mechanism of the downregulation for CYP1A2 remains unclear, the presently reported results suggest that the downregulation of CYP2B6 and CYP3A4 via HIF-α stabilization is caused by a decrease in the expressions of CAR, PXR, and RXR. In the experiment, the researchers used many compounds, for example, Methyl 6-Cyanopyridine-3-carboxylate (cas: 89809-65-4Quality Control of Methyl 6-Cyanopyridine-3-carboxylate).

Methyl 6-Cyanopyridine-3-carboxylate (cas: 89809-65-4) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of âˆ?8.7 × 10âˆ? cm3·molâˆ?.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·molâˆ? in the liquid phase and 140.4 kJ·molâˆ? 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.Quality Control of Methyl 6-Cyanopyridine-3-carboxylate

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Water as a Hydroxy Source in a Rh^III-Catalyzed Directed C-H Hydroxylation of 2-Arylpyridines was written by Kim, Kiseong;Hyun, Jaeyong;Kim, Jin;Kim, Hyunwoo. And the article was included in Asian Journal of Organic Chemistry in 2017.COA of Formula: C12H11N This article mentions the following:

A [Rh^IIICp*]-catalyzed directed C-H hydroxylation of 2-arylpyridines was described (Cp*=1,2,3,4,5-pentamethylcyclopenta-2,4-dienyl), in which the combination of [(RhCp*Cl₂)₂]/AgF, PhI(OPiv)₂ and water was used as an effective catalytic system. According to mechanistic studies, including ¹⁸O-labeling experiments and X-ray crystallog. anal. of an intermediate Rh complex, it was demonstrated that water and PhI(OPiv)₂ were required for Rh catalysis as the hydroxy source and the oxidant, resp. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9COA of Formula: 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. 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.COA of Formula: C12H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Chalcogen-Bonded Cocrystals of Substituted Pyridine N-Oxides and Chalcogenodiazoles: An X-ray Diffraction and Solid-State NMR Investigation was written by Xu, Yijue;Kumar, Vijith;Bradshaw, Maressa J. Z.;Bryce, David L.. And the article was included in Crystal Growth & Design in 2020.Application of 3718-65-8 This article mentions the following:

Me, MeO, and Ph substituents are introduced at the para-, meta-, and ortho- positions of pyridine N-oxide to study the effect of chem. substitution on the resulting 9 chalcogen-bonded structures formed upon cocrystn. with 3,4-dicyano-1,2,5-selenodiazole and 3,4-dicyano-1,2,5-telluradiazole. Single-crystal x-ray diffraction studies reveal double chalcogen bonding interactions in the cocrystals and demonstrate the impact of the substitution on the geometric features of the chalcogen bonds. ⁷⁷Se and ¹²⁵Te solid-state NMR spectroscopy is employed to measure Se and Te chem. shift tensors of the products, and various trends are described. The smallest component of the ⁷⁷Se chem. shift tensor (δ₃₃) provides the strongest correlation with the chalcogen bond distance. Solution NMR provides qual. evidence for the persistence of the chalcogen bonds in solution ¹J(⁷⁷Se,¹⁴N) coupling constants in 3,4-dicyano-1,2,5-selenodiazole and its chalcogen-bonded cocrystals are measured after accounting for residual dipolar coupling between ⁷⁷Se and ¹⁴N; however, changes in ¹J(⁷⁷Se,¹⁴N) attributable to chalcogen bonding upon cocrystn. are comparable to the exptl. uncertainties. This systematic study of chalcogen-bonded cocrystals demonstrates the potential utility of the substitution effect for applications of chalcogen bonds in crystal engineering and demonstrates the value of solid-state NMR in characterizing such systems. Chalcogen-bonded cocrystals based on 3,4-dicyano-1,2,5-selenodiazole and 3,4-dicyano-1,2,5-telluradiazole are reported. Various substituted pyridine N-oxides act as electron donors. X-ray diffraction and ⁷⁷Se/¹²⁵Te solid-state NMR are employed to characterize these novel materials. 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. 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.Application of 3718-65-8

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Chemical synthesis, molecular docking and MepA efflux pump inhibitory effect by 1,8-naphthyridines sulfonamides was written by Oliveira-Tintino, Cicera Datiane de Morais;Tintino, Saulo Relison;Muniz, Debora Feitosa;Rodrigues dos Santos Barbosa, Cristina;Pereira, Raimundo Luiz Silva;Begnini, Ieda Maria;Rebelo, Ricardo Andrade;da Silva, Luiz Everson;Mireski, Sandro Lucio;Nasato, Michele Caroline;Krautler, Maria Isabel Lacowicz;Pereira, Pedro Silvino;Balbino, Tereza Cristina Leal;da Costa, Jose Galberto Martins;Rodrigues, Fabiola Fernandes Galvao;Teixeira, Alexandre Magno Rodrigues;Barreto, Humberto Medeiros;de Menezes, Irwin Rose Alencar;Coutinho, Henrique Douglas Melo;da Silva, Teresinha Goncalves. And the article was included in European Journal of Pharmaceutical Sciences in 2021.Safety of N-(6-Aminopyridin-2-yl)acetamide This article mentions the following:

To evaluate the antibacterial activity and to verify, in silico and in vitro, the inhibition of efflux mechanisms using a series of synthesized 1,8-naphthyridines sulfonamides I [R = 4-Me, 2,5-(Cl)₂, 3-CF₃, etc.] against Staphylococcus aureus strains carrying MepA efflux pumps were reported. The chem. synthesis occurred through the thermolysis of the Meldrums acid adduct. The sulfonamide derivatives I were obtained by the sulfonylation of 2-amino-5-chloro-1,8-naphthyridine with com. benzenesulfonyl chloride. Antibacterial activity was assessed by the broth microdilution test. Efflux pump inhibitory capacity was evaluated in silico by mol. docking and in vitro by analyzing synergistic effects on ciprofloxacin and ethidium bromide (EtBr) and by EtBr fluorescence emission assays. The following 1,8-naphthyridines were synthesized: I [R = 4-Me, 2,5-(Cl)₂, 4-F, 2,3,4-(F)₃, 3-CF₃, 2,5-(F)₂,4-Br]. The 1,8-naphthyridines derivatives I associated with sulfonamides did not showed antibacterial activity. However, they showed a favorable pharmacokinetic profile with possible MepA efflux pump inhibitory action, demonstrated in mol. docking. In addition to the promising results in reducing the concentration of intracellular EtBr. 1,8-naphthyridines I acted as putative agents in the inhibitory action of the MepA efflux pump. In the experiment, the researchers used many compounds, for example, N-(6-Aminopyridin-2-yl)acetamide (cas: 1075-62-3Safety of N-(6-Aminopyridin-2-yl)acetamide).

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

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Transition-Metal-Catalyzed Transformation of Sulfonates via S-O Bond Cleavage: Synthesis of Alkyl Aryl Ether and Diaryl Ether was written by Chen, Xuemeng;Xiao, Xue;Sun, Haotian;Li, Yue;Cao, Haolin;Zhang, Xuemei;Yang, Shengyong;Lian, Zhong. And the article was included in Organic Letters in 2019.Application of 4783-68-0 This article mentions the following:

The catalytic conversion of sulfonates, a versatile class of pharmaceutical intermediates, is usually based on C-O bond cleavage. In this paper, however, a rare transformation of sulfonates R¹SO₂OR² [R¹ = 2-pyridyl, 3-methyl-2-pyridyl, 5-trifluoromethyl-2-pyridyl, etc.; R² = Ph, 2-naphthyl, 3-quinolyl, Ph(CH₂)₃, 1-heptyl, 2-adamantyl, etc.] via S-O bond cleavage catalyzed by transition metal. Alkyl sulfonates underwent an intramol. desulfitative C-O coupling to form aryl alkyl ethers in the presence of a nickel catalyst, whereas aryl sulfonates performed similarly under palladium complex catalysis to give diaryl ethers. This transformation could tolerate a wide range of functionalities. Controlled experiments revealed that the 2-pyridyl group is necessary to promote the reaction as designed. Crossover experiments proved that this transformation might proceed partly in an intermol. pathway. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Application of 4783-68-0).

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

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Dual Photoredox/Palladium-Catalyzed C-H Acylation of 2-Arylpyridines with Oxime Esters was written by He, Bin-Qing;Gao, Yuan;Wang, Peng-Zi;Wu, Hong;Zhou, Hong-Bin;Liu, Xiao-Peng;Chen, Jia-Rong. And the article was included in Synlett in 2021.Electric Literature of C12H11N This article mentions the following:

An unprecedented dual photoredox/palladium-catalyzed iminyl-radical-mediated C-C bond cleavage and directed orthoC-H acylation of 2-arylpyridines by using oxime esters was described. Oxime esters was serve as efficient acyl sources through formation of the corresponding acyl radicals by photoredox-catalyzed iminyl-radical-mediated C-C bond cleavage. This redox-neutral protocol features excellent regioselectivity, a broad substrate scope, and good functional-group tolerance with respect to both components, giving a broad range of aryl ketones with generally good yields. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Electric Literature of C12H11N).

2-(m-Tolyl)pyridine (cas: 4373-61-9) 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 derivatives are also useful as small-molecule α-helix mimetics that inhibit protein-protein interactions, as well as functionally selective GABA ligands.Electric Literature of C12H11N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Copper-catalyzed cross-coupling of aryl-, primary alkyl-, and secondary alkylboranes with heteroaryl bromides was written by Bergmann, Allison M.;Oldham, Adam M.;You, Wei;Brown, M. Kevin. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2018.Category: pyridine-derivatives This article mentions the following:

A method for the Cu-catalyzed cross-coupling of both aryl and alkylboranes with aryl bromides was described. The method employed an inexpensive Cu-catalyst and functions for a variety of heterocyclic as well as electron deficient aryl bromides. In addition, aryl iodides of varying substitution patterns and electronic properties worked well. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4Category: pyridine-derivatives).

2-Isopropylpyridine (cas: 644-98-4) 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.Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Thione-thiol rearrangement of xanthates catalyzed by pyridine N-oxides. Remarkable enhanced reactivity of 4-dialkylaminopyridine N-oxides was written by Harano, Kazunobu;Nakagawa, Hidetoshi;Kamei, Kumiko;Kiyonaga, Hideo;Hisano, Takuzo. And the article was included in Chemical & Pharmaceutical Bulletin in 1992.Category: pyridine-derivatives This article mentions the following:

Pyridine N-oxides (III; R = electron-donating substituents) are efficient catalysts for rearrangement of O-alkyl S-Me dithiocarbonates (xanthates) (I) to the corresponding S-alkyl S-Me dithiocarbonates (dithiolcarbonates) (II). Of the catalysts tested, III [R = piperidino (IV)] is the best from the viewpoints of catalytic activity and solubility in I. Heating of I in the presence of catalytic amounts (0.02-0.05 M eq) of IV gave II together with the sym. S,S-dialkyl and S,S-di-Me dithiocarbonates in good yields. The catalytic behavior of III is discussed on the basis of kinetic and MO data. The complete calculation of the perturbation equation on the initial stage of the reaction was consistent with the exptl. observed activity of the catalysts. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Category: pyridine-derivatives).

3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) 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.Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Carboline synthesis by the method of Graebe Ullmann I was written by Namirski, Pawel Nantka. And the article was included in Acta Poloniae Pharmaceutica in 1961.COA of Formula: C5H2Cl2N2O2 This article mentions the following:

3-Nitro-4-pyridone (14 g.) in 200 ml. 50% AcOH treated at 25-30° with Cl gave 46% 3-nitro-4-hydroxy-5-chloropyridine (I), m. 263°. I (17.5 g.), 25 g. P₂O₅, and 10 ml. POCl₃ heated to give a brown solution, volatile portion evaporated in vacuo, the residue neutralized with Na₂CO₃, extracted with Et₂O, and the extract distilled gave 19.1 g. 3-nitro-4,5-dichloropyridine (II), m. 43-7°, strong lachrymator. II (1.9 g.) in 15 ml. Me₂CO heated 2 hrs. on a water bath with 20 ml. 25% NH₄OH yielded 1 g. light yellow 3-nitro-4-amino-5-chloropyridine, m. 181° (EtOH); similarly, 1.9 g. II in 15 ml. EtOH heated 30 min. with 5 ml. 80% (NH₂)₂.H₂O gave 1.3 g. 3-nitro-4-hydrazino-5-chloropyridine, golden needles, m. 199° (EtOH). I (17.5 g.) and 25 g. PCl₅ in 50% AcOH treated at 25-30° with Cl, the volatile products distilled, the residue treated portionwise with 100 g. SnCl₂ in 250 ml. concentrated HCl, heated 30 min. on a water bath, cooled, treated with 30 ml. concentrated HCl, the precipitated adduct decomposed with 20% NaOH, the mixture extracted with Et₂O, and the extract treated with concentrated HNO₃ gave 16.5 g. 3-amino-4,5-dichloropyridine (III) nitrate, m. 169° (EtOH); III, needles m. 108°. Analogously, 22.5 g. 3 nitro-4-hydroxy-5-bromopyridine yielded 21 g. 3-amino-4-chloro-5-bromopyridine nitrate, m. 176°, and free base, m. 108.5°. II (19.3 g.) and 25 ml. PhNH₂ heated 2 hrs. on a water bath, alkalized with NH₄OH the excess PhNH₂ steam distilled, the residue dissolved in HCl, treated with C, and then with NH₄OH yielded 50% yellow 3-nitro-4-anilino-5-chloropyridine (IV), m. 148-8.5° (EtOH). IV was also prepared in 93% yield when 17.5 g. I was chlorinated as above, the volatile products distilled, the residue heated 2 hrs. on a water bath with 150 ml. AcOH, 10 g. PhNH₂, and 15 g. anhydrous AcONa, the mixture diluted with 500 ml. H₂O, neutralized with NH₄OH, the gummy precipitate extracted with HCl, and reprecipitated with NH₄OH; the 5-bromo analog of IV, m. 153.5-54°, was prepared by this method in 94% yield. IV (25 g.) added portionwise to 75 g. Na₂S in 300 ml. H₂O, the mixture heated 3 hrs. at 90-100°, the precipitate extracted with Et₂O, and the extract treated with concentrated HNO₃ gave 3-amino-4-anilino-5-chloropyridine (V) nitrate, which alkalized with Na₂CO₃ in aqueous solution yielded 71% V, m. 149.5° (H₂O); the 5-bromo analog (79%) m. 144.5° (EtOH). V (11 g.) diazotized in 300 ml. 50% H₂SO₄ with 3.5 g. NaNO₂ in 50 ml. H₂O and the solution treated with NH₄OH yielded 92% 1-phenyl-7-chloro-v-triazolo[4,5-c]pyridine (VI), m. 141-1.5°; the 7-bromo analog (96%) m. 149° (50% EtOH). Evolution of N began at 240° and ceased at 290° when 9.6 g. VI was heated in 30 ml. H₃PO₄; the residue was dissolved in 200 ml. H₂O, treated with NH₄OH, the mixture extracted repeatedly with Et₂O, and the extract evaporated to give 2.9 g. crude, yellow 1-chloro-β-carboline (VII), m. 233-4° after repeated crystallizations from H₂O and EtOH; purification via the HCl salt (m. 311-12°) raised the m.p. of VII to 270° and gave a colorless product. Analogously were prepared: 1-bromo-γ-carboline, m. 240-1.5° (crude 233-4°) (HCl salt (VIII) m. 301-3°); 1-iodo-γ-carboline, yellowish crystals, m. 242-3° (crude 229-32°). In biol. tests, the inhibition of monoamine oxidase by VIII was 80% of that of phenethylhydrazine. In the experiment, the researchers used many compounds, for example, 3,4-Dichloro-5-nitropyridine (cas: 56809-84-8COA of Formula: C5H2Cl2N2O2).

3,4-Dichloro-5-nitropyridine (cas: 56809-84-8) 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. 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.COA of Formula: C5H2Cl2N2O2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem