Day: January 5, 2023

Benzalkonium chloride and cetylpyridinium chloride induce apoptosis in human lung epithelial cells and alter surface activity of pulmonary surfactant monolayers. was written by Kanno, Sanae;Hirano, Seishiro;Kato, Hideaki;Fukuta, Mamiko;Mukai, Toshiji;Aoki, Yasuhiro. And the article was included in Chemico-Biological Interactions in 2020.Electric Literature of C5H6ClN This article mentions the following:

To examine whether BAC and CPC aerosols deposited in the alveolar region alter pulmonary function, we studied the effects on pulmonary surfactant using two-step in vitro models; cytotoxicity using A549 alveolar epithelial cell and changes in surface activity of the pulmonary surfactant monolayer using both Surfacten and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). Cell viability was decreased with BAC and CPC dose-dependently. A comparison of cytotoxicity among BAC homologues with different length of alkyl chain showed that C₁₆-BAC, which has the longest alkyl chain, was more cytotoxic than C₁₂– or C₁₄-BAC. Caspase-3/7 activity and cleaved form of caspase-3 and PARP were increased in BAC- and CPC-exposed cells. The elevated caspase-3/7 activity and their cleaved active forms were abolished by caspase-3-inhibitor. The collapse pressure diminished with increasing concentration of CPC. Topog. images indicated that BAC and CPC resulted in smaller condensed lipid domains compared to the control. Conversely, PC without hydrocarbon tail group, showed no cytotoxicity and did not change the isotherms and AFM images. These results indicate that BAC and CPC cause cell death via caspase-3-dependent apoptotic pathway in A549 cells and alter the alveolar surfactant activity. These effects can be attributed to the long alkyl chain of BAC and CPC. In the experiment, the researchers used many compounds, for example, Pyridinehydrochloride (cas: 628-13-7Electric Literature of C5H6ClN).

Pyridinehydrochloride (cas: 628-13-7) 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 groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Electric Literature of C5H6ClN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis of 2-Substituted Pyridines via a Regiospecific Alkylation, Alkynylation, and Arylation of Pyridine N-Oxides was written by Andersson, Hans;Almqvist, Fredrik;Olsson, Roger. And the article was included in Organic Letters in 2007.Application In Synthesis of 3,5-Dimethylpyridine 1-oxide This article mentions the following:

Sequential addition of Grignard reagents to pyridine N-oxides in THF at room temperature followed by treatment with acetic anhydride at 120 °C afforded 2-substituted pyridines, e.g. I (R = H), in good to high yields. Furthermore, by exchanging acetic anhydride for DMF in the second step, a 2-substituted pyridine N-oxide II was obtained, as an intermediate suitable for addition of a second Grignard reagent for the synthesis of 2,6-disubstituted pyridines I (R = Ph, p-MePh). 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. 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). 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

6-Substituted 2-Oxo-2H-1-benzopyran-3-carboxylic Acid as a Core Structure for Specific Inhibitors of Human Leukocyte Elastase was written by Doucet, Caroline;Pochet, Lionel;Thierry, Nicole;Pirotte, Bernard;Delarge, Jacques;Reboud-Ravaux, Michele. And the article was included in Journal of Medicinal Chemistry in 1999.Electric Literature of C6H6N2O3 This article mentions the following:

Pyridyl esters of 6-substituted 2-oxo-2H-1-benzopyran-3-carboxylic acid were designed as mechanism-based inhibitors of human leukocyte elastase. Compounds of chloropyridylbenzopyran carboxylates (e.g., I) specifically inhibited this enzyme. Several of the tested compounds [substituted pyridylchloromethylbenzopyran carboxylates (e.g., II and III)] acted as powerful time-dependent inhibitors of both human leukocyte elastase and α-chymotrypsin; some compounds of these series inhibited thrombin. Trypsin was not inhibited. A transient inactivation was observed for human leukocyte elastase (k_i/K_I = 107 000 M^-1·s^-1 for I) and thrombin (k_i/K_I = 7 200 M^-1·s^-1 for III) as demonstrated by spontaneous or hydroxylamine-accelerated reactivation, irresp. of the nature of the substituent at the 6-position. Conversely, α-chymotrypsin was irreversibly inhibited by 6-chloromethyl derivatives (k_i/K_I = 107 400 M^-1·s^-1 for III). The presence of a latent alkylating function at the 6-position (chloromethyl group) was required for leading to this inactivation. In the absence of such an alkylating function (e.g., I), human leukocyte elastase was specifically inhibited suggesting that this new series of human leukocyte elastase inhibitors may be of potential therapeutic interest in degradative and degenerative processes involving this enzyme. In the experiment, the researchers used many compounds, for example, 3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2Electric Literature of C6H6N2O3).

3-Hydroxy-6-methyl-2-nitropyridine (cas: 15128-90-2) 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. Electric Literature of C6H6N2O3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Sphere to rod transitions in homologous alkylpyridinium salts: A Stauff-Klevens-type equation for the second critical micelle concentration was written by Gonzalez-Perez, A.;Varela, L. M.;Garcia, M.;Rodriguez, J. R.. And the article was included in Journal of Colloid and Interface Science in 2006.Electric Literature of C17H30BrN This article mentions the following:

The authors analyze the dependence of the 2nd critical micelle concentration (2nd cmc) of ionic amphiphiles on the number of atoms in the hydrocarbon mol. chain, n_c. A mol. thermodn. model for the interaction energy between the end caps of rodlike micelles, g(N), is introduced and the linear dependence of this object on n c analyzed, thus leading to a Stauff-Klevens-like behavior of the 2nd cmc. The predictions agree with previously reported data for n-alkyldimethylbenzylammonium chloride (C_nBACl) for n-alkylpyridinium chloride (C_nPyCl) and n-alkyltrimethylammonium bromide (C_nTABr) at 35°. These conclusions are reinforced by the conductivity, d., and ultrasound velocity measurements of the 2nd cmc of several C_nPyCl (n = 12, 14, 16) and n-alkylpyridinium bromides (C_nPyBr, n = 12, 14, 15, 16) presented. In the experiment, the researchers used many compounds, for example, 1-Dodecylpyridin-1-ium bromide (cas: 104-73-4Electric Literature 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. 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 C17H30BrN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Iodine-promoted synthesis of acylindolizine derivatives from acetylenecarboxylates and pyridinium, isoquinolinium, or quinolinium ylides was written by Liu, Juanjuan;Yan, Peiyun;Li, Yan;Zhou, Zhengquan;Ye, Weijian;Yao, Juan;Wang, Cunde. And the article was included in Monatshefte fuer Chemie in 2014.Electric Literature of C7H7ClN2 This article mentions the following:

An iodine-promoted synthesis of acylindolizinecarboxylates via 1,3-dipolar cycloaddition of nitrogen ylides with acetylenecarboxylates and subsequent aromatization for the generation of a wide range of structurally interesting, pharmacol. and photoelec. significant compounds is reported. Only readily available materials, mild conditions, and operationally trivial reaction protocols were required. In the experiment, the researchers used many compounds, for example, 1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3Electric Literature of C7H7ClN2).

1-(Cyanomethyl)pyridin-1-ium chloride (cas: 17281-59-3) 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). 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.Electric Literature of C7H7ClN2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

A versatile rhodium(III) catalyst for direct acyloxylation of aryl and alkenyl C-H bonds with carboxylic acids was written by Chen, Changjun;Pan, Yixiao;Zhao, Haoqiang;Xu, Xin;Xu, Jianbin;Zhang, Zongyao;Xi, Siqi;Xu, Lijin;Li, Huanrong. And the article was included in Organic Chemistry Frontiers in 2018.Reference of 4783-68-0 This article mentions the following:

Rh(III)-catalyzed highly regioselective direct acyloxylation of sp² C-H bonds with carboxylic acids was developed. The catalytic system consisting of a cationic Rh(III) complex and a silver oxidant allowed a variety of arenes and alkenes bearing different directing groups (not limited to strongly coordinating N-heterocyclic directing groups) to undergo efficient acyloxylation with a broad range of readily available alkyl, alkenyl and aryl carboxylic acids, and a number of valuable functional groups in both coupling partners were well tolerated in the reaction regardless of their electronic properties and positions. This method provided a straightforward and convenient access to various valuable acyloxylated products. Furthermore, the synthetic utility of this protocol was demonstrated by the later-stage functionalization and modification of biol. active compounds Mechanistic studies revealed the involvement of five-membered rhodacycles as key intermediates. 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 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. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Reference of 4783-68-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Palladium(II)-Catalyzed Ortho Arylation of 2-Phenoxypyridines with Potassium Aryltrifluoroborates via C-H Functionalization was written by Chu, Jean-Ho;Lin, Pi-Shan;Wu, Ming-Jung. And the article was included in Organometallics in 2010.Safety of 2-Phenoxypyridine This article mentions the following:

An efficient synthesis of ortho-arylated 2-phenoxypyridines catalyzed by Pd acetate is described. Treatment of 2-phenoxypyridines with two and a half equivalent of K aryltrifluoroborate and 10 mol % of Pd(OAc)₂ in the presence of two equivalent of Ag₂CO₃, one equivalent of p-benzoquinone (BQ), and four equivalent of DMSO with (or without) H₂O at 130-140° for 48 h in dried CH₂Cl₂ gave the ortho-arylated 2-phenoxypyridines in modest to excellent yields. P-Benzoquinone is an important ligand and cooxidant for the transmetalation reductive elimination step in the catalytic reaction. The study of kinetic isotope effect (k_H/k_D) is 5.25, which indicates that C-H bond cleavage occurs in the rate-determining step. One of the arylated compounds, 2-(4′-nitrobiphenyl-2-yloxy)pyridine, was treated with Me trifluoromethanesulfonate and subsequently Na methoxide to give the 2-(4-nitrophenyl)phenol in 79% yield, demonstrating that pyridine is a removable directing group. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Safety of 2-Phenoxypyridine).

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

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Octanol-water partition coefficients of simple organic compounds was written by Sangster, James. And the article was included in Journal of Physical and Chemical Reference Data in 1989.Recommanded Product: 27876-24-0 This article mentions the following:

Octanol-water partition coefficients (log P) for 634 organic compounds representing all principle classes were retrieved from the literature and are critical evaluated. Recommendations are given. Pertinent thermodn. relations are presented, with a discussion of direct and indirect methods of measurements. In the experiment, the researchers used many compounds, for example, 4-Hexylpyridine (cas: 27876-24-0Recommanded Product: 27876-24-0).

4-Hexylpyridine (cas: 27876-24-0) 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). 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: 27876-24-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Imidazolium-Based Ionic Liquid: An Efficient, Normalized, and Recyclable Platform for Rh(III)-Catalyzed Directed C-H Carbenoid Coupling Reactions was written by Zhang, Chen;Chen, Xiao-Mei;Luo, Yi;Li, Jiang-Lian;Chen, Min;Hai, Li;Wu, Yong. And the article was included in ACS Sustainable Chemistry & Engineering in 2018.Reference of 4373-61-9 This article mentions the following:

The ionic liquid [BMIM][NTf₂] was developed as an ideal medium in which Rh(III)-catalyzed directed C-H carbenoid coupling reactions can be conducted efficiently and sustainably. More significantly, the ionic liquid can not only achieve the recycle of catalyst system but also improve the efficiency of catalyst, presenting that carbenoid coupling reactions can be accomplished at room temperature within a short period of time. Thus, this work would be useful in expanding applications of C-H activation strategies as tools for assembling novel organic mols. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9Reference of 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. 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.Reference of 4373-61-9

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Recommendable routes to trifluoromethyl-substituted pyridine- and quinolinecarboxylic acids was written by Cottet, Fabrice;Marull, Marc;Lefebvre, Olivier;Schlosser, Manfred. And the article was included in European Journal of Organic Chemistry in 2003.Reference of 175205-82-0 This article mentions the following:

As part of a case study, rational strategies for the preparation of all ten 2-, 3-, or 4-pyridinecarboxylic acids and all nine 2-, 3-, 4-, or 8-quinolinecarboxylic acids bearing trifluoromethyl substituents at the 2-, 3-, or 4-position were elaborated. The trifluoromethyl group, if not already present in the precursor, was introduced either by the deoxygenative fluorination of suitable carboxylic acids with sulfur tetrafluoride or by the displacement of ring-bound bromine or iodine by trifluoromethylcopper generated in situ. The carboxy function was produced by treatment of organolithium or organomagnesium intermediates, products of halogen/metal or hydrogen/metal permutation, with carbon dioxide. In the experiment, the researchers used many compounds, for example, 2-Bromo-3-(trifluoromethyl)pyridine (cas: 175205-82-0Reference of 175205-82-0).

2-Bromo-3-(trifluoromethyl)pyridine (cas: 175205-82-0) 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 175205-82-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem