Month: January 2023

Caveat regarding the use of substituent parameters in statistical analyses of molecular properties. II. Case study: carbon-13 NMR of 2-substituted pyridines and monosubstituted benzenes was written by Cook, Iain B.. And the article was included in Australian Journal of Chemistry in 1989.Recommanded Product: 2-Phenoxypyridine This article mentions the following:

Carbon-13 NMR substituent chem. shifts of equivalent positions on monosubstituted benzenes and 2-substituted pyridines are analyzed by multiple linear regression on combinations of field, resonance, electronegatively and three polarizability parameters. The ortho and meta positions of the 2-pyridine and benzene series are poorly described by σ_F and σ_R parameters, but a much improved fit is obtained when σ_x and/or a bond polarizability parameter σ_α (C-X) are included. The mechanism of shift formation differs markedly between the two systems when the C(2), C(4), and C(6) positions on pyridine are compared with the geometrically equivalent positions on benzenes. Owing to the high degree of interdependence between the four substituent effects, quant. anal. proved to be impossible. However, use of subsets of substituents with three of the four parameters approx. orthogonal enabled the mechanism to be deduced in most cases. It is postulated that the differences between the pyridine and benzene systems arises from perturbation of the C-N bond polarity. A mechanism to explain the results is presented. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Recommanded Product: 2-Phenoxypyridine).

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

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The preparation of 3-fluoroisonicotinic acid and related compounds was written by Roe, Arthur;Seligman, Robert B.. And the article was included in Journal of Organic Chemistry in 1955.Computed Properties of C6H6FN This article mentions the following:

To study the effect of a F atom adjacent to the CO₂H group on the antituberculostatic activity of isonicotinic acid hydrazide, 3-fluoroisonicotinic acid (I) and some related compounds are prepared 2-Amino-4-picoline (50 g.) is converted by the method of Hawkins and Roe (C.A. 44,628i) into the nitramine and allowed to rearrange to 3- and 5-nitro-2-amino-4-picoline, which are hydrolyzed to a mixture (II), m. 159°, of 3-(III) and 5-nitro-2-hydroxy-4-picoline (IV). Warming 2.5 g. IV 2.5 hrs. with 20 cc. POCl₃ gives 60.7% 2-chloro-5-nitro-4-picoline (V), b₅ 91.2°, m. 38.5-9.5°. Similarly, III gives 2-chloro-3-nitro-4-picoline (VI), m. 52-2.9°. Treating II with POCl₃ gives a mixture of V and VI which (25 g.) is hydrogenated in 20 cc. AcOH in the presence of 0.5 g. NaOAc and 10% Pd-C at 65 lb. H pressure, the mixture evaporated in vacuo, and the residue made strongly alk. and extracted with Et₂O, giving 89.5% 3-amino-4-picoline (VII), m. 104-5° (picrate, m. 177-8°). VII is converted by a modified Schiemann reaction into 4-picoline-3-diazonium fluoborate which, decomposed in boiling petr. ether (b.p. 60-90°), gives 68% 3-fluoro-4-picoline (VIII), b₇₄₈ 135.6°, n_D^27.5 1.4795 (picrate, yellow plates, m. 129-30°). Adding dropwise (3.5 hrs.) 48 g. KMnO₄ in H₂O to 17 g. VIII in 1 l. refluxing H₂O, steam distilling the mixture to remove any unchanged VIII, evaporating the filtered solution until crystallization sets in, and acidifying it with HCl gives 45% I, m. 256-7° (decomposition and sublimation). Refluxing 2 g. I 1.5 hrs. with 20 cc. SOCl₂, distilling off the excess SOCl₂, and refluxing the residue 1 hr. with EtOH gives Et 3-fluoroisonicotinate-HCl (IX.HCl), from which 83.4% IX, b₇₅₂ 215°, is obtained (picrate, long yellow needles, m. 109-10°). Refluxing 2 g. IX 5.5 hrs. with 1.5 cc. 85% N₂H₄.H₂O and 20 cc. 95% EtOH and distilling off the EtOH gives 92% I hydrazide, fine needles, m. 146.8-7.8°. IX.HCl refluxed with N₂H₄.H₂O 36 hrs. forms 3-hydroxyisonicotinic acid hydrazide. In the experiment, the researchers used many compounds, for example, 3-Fluoro-4-methylpyridine (cas: 399-88-2Computed Properties of C6H6FN).

3-Fluoro-4-methylpyridine (cas: 399-88-2) 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.Computed Properties of C6H6FN

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Electric dipole moments of 2,4-dihalopicolines and their N-oxides was written by Puszko, A.. And the article was included in Chemical Papers in 1990.Electric Literature of C6H5Br2N This article mentions the following:

Dipole moment values of 2,4-dichloro- and 2,4-dibromopicolines and their N-oxides were calculated from the permittivity and refractive indexes measurements as well as by means of composition of groups and bonds moments vectors. The influence of substituents effects on the dipole moment values was discussed and the results obtained were compared. In the experiment, the researchers used many compounds, for example, 2,4-Dibromo-5-methylpyridine (cas: 79055-50-8Electric Literature of C6H5Br2N).

2,4-Dibromo-5-methylpyridine (cas: 79055-50-8) 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. 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. Electric Literature of C6H5Br2N

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Synthesis and structure-activity relationship study of water-soluble carbazole sulfonamide derivatives as new anticancer agents was written by Liu, Yonghua;Wu, Yanbin;Sun, lianqi;Gu, Yuxi;Hu, Laixing. And the article was included in European Journal of Medicinal Chemistry in 2020.Reference of 28020-37-3 This article mentions the following:

Here, the structure-activity relationships of novel N-substituted carbazole sulfonamide derivatives I [R¹ = H, CH₂CH₂OH, 3-(1-piperidyl)propanoyl, etc.; R² = H, OH, OP(O)(ONa)₂] with improved physicochem. properties was formulated and investigated. Most of these new compounds displayed good aqueous solubility Certain mols. presented strong in vitro antiproliferative and in vivo antitumor activity. Relative to the control, 50 mg/kg compound I [R¹ = CH₂CH₂OP(O)(ONa)₂; R² = H] substantially reduced human HepG2 xenograft mouse tumor growth by 54.5% and its efficacy was comparable to that of CA-4P. Compound I [R¹ = 2-(4-methylpiperazin-1-yl)ethyl; R² = H] demonstrated anticancer efficacy in both s.c. and orthotopic HepG2 xenograft mouse models. A novel synthetic method for 7-hydroxy-substituted carbazole sulfonamides was also developed. Compared with the control, 25 mg/kg compound I [R¹ = H; R² = OP(O)(ONa)₂] inhibited human HepG2 xenograft mouse tumor growth by 71.7% and was more potent than 50 mg/kg CA-4P with only 50% tumor shrinkage efficacy. Among the three water-soluble carbazole sulfonamide derivatives formulated in the present study, compound I [R¹ = H; R² = OP(O)(ONa)₂] displayed the most effective tumor growth inhibition in vivo and merit further investigation as potential antitumor agents for cancer therapy. In the experiment, the researchers used many compounds, for example, 3-Amino-2,6-dimethoxypyridine (cas: 28020-37-3Reference of 28020-37-3).

3-Amino-2,6-dimethoxypyridine (cas: 28020-37-3) 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. 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.Reference of 28020-37-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Selective Isomerization via Transient Thermodynamic Control: Dynamic Epimerization of trans to cis Diols was written by Oswood, Christian J.;MacMillan, David W. C.. And the article was included in Journal of the American Chemical Society in 2022.Application of 85838-94-4 This article mentions the following:

Traditional approaches to stereoselective synthesis require high levels of enantio- and diastereocontrol in every step that forms a new stereocenter. Here, authors report an alternative approach, in which the stereochem. of organic substrates is selectively edited without further structural modification, a strategy with the potential to allow new classes of late-stage stereochem. manipulation and provide access to rare or valuable stereochem. configurations. In this work, authors describe a selective epimerization of cyclic diols enabled by hydrogen atom transfer photocatalysis and boronic acid mediated transient thermodn. control, selectively generating less stable cis products from the otherwise favored trans isomers. A range of substitution patterns and ring sizes are amenable to selective isomerization, including stereochem. complex polyols such as estriol, as well as syn to anti epimerization of acyclic vicinal diols. Moreover, this strategy has enabled the divergent epimerization of saccharide anomers, providing access to distinct sugar isomers from α- or β-configured glycosides. In the experiment, the researchers used many compounds, for example, tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (cas: 85838-94-4Application of 85838-94-4).

tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (cas: 85838-94-4) 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, 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 of 85838-94-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Desulfurization of fuel using ionic liquids: computational selection of cation and anion was written by Salleh, M. Zulhaziman M.;Wilfred, Cecilia D.;Abdul Mutalib, M. I.. And the article was included in Applied Mechanics and Materials in 2014.Recommanded Product: 125652-55-3 This article mentions the following:

Selection of potential ionic liquid (IL) is carried out in this work using COSMO-RS by analyzing the interaction between dibenzothiophene (DBT) and IL in dodecane. Sigma profile, capacity and selectivity at infinite dilution were used to predict the suitable ILs in desulfurization. Result shows that increasing alkyl length and incorporating nitrile group will increase the capacity and selectivity resp. 1-butyl-6-methylquinolonium [C₄mquin]⁺, 1-butyl-3- methylimidazolium [Bmim]⁺, thiocyanate [SCN]^– and dicyanamide [N(CN)₂]^– are potentially good cations and anions. In the experiment, the researchers used many compounds, for example, 1-Butyl-3-methylpyridinium Chloride (cas: 125652-55-3Recommanded Product: 125652-55-3).

1-Butyl-3-methylpyridinium Chloride (cas: 125652-55-3) 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, 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. Recommanded Product: 125652-55-3

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Palladium-Catalyzed Site-Selective Amidation of Dichloroazines was written by Young, Ian S.;Glass, Anna-Lena;Cravillion, Theresa;Han, Chong;Zhang, Haiming;Gosselin, Francis. And the article was included in Organic Letters in 2018.Category: pyridine-derivatives This article mentions the following:

A highly site-selective amidation reaction of substituted 2,4-dichloroazines is reported. Palladium acetate/1,1′-bis(diphenylphosphino)ferrocene (dppf) was identified as the optimal catalyst system, producing >99:1 C-2/C-4 selectivity for most examples. The generality of this transformation was demonstrated through a survey of a diverse amide/substituted 2,4-dichloroazine scope, leading to the preparation of the desired C-2 amidated products in good to excellent yields. In the experiment, the researchers used many compounds, for example, 2,4-Dichloro-3-fluoropyridine (cas: 628691-85-0Category: pyridine-derivatives).

2,4-Dichloro-3-fluoropyridine (cas: 628691-85-0) 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. 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. Category: pyridine-derivatives

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Novel bisphosphonate inhibitors of the human farnesyl pyrophosphate synthase was written by De Schutter, Joris W.;Zaretsky, Serge;Welbourn, Sarah;Pause, Arnim;Tsantrizos, Youla S.. And the article was included in Bioorganic & Medicinal Chemistry Letters in 2010.Recommanded Product: 131747-45-0 This article mentions the following:

A structure-based approach was pursued in designing novel bisphosphonate inhibitors of the human farnesyl pyrophosphate synthase (hFPPS). Preliminary SAR and structural evidence for the simultaneous binding of these inhibitors into the isopentenyl pyrophosphate (IPP) and the geranyl pyrophosphate (GPP) substrate sub-pockets of the enzyme are presented. In the experiment, the researchers used many compounds, for example, (4-Bromopyridin-2-yl)methanol (cas: 131747-45-0Recommanded Product: 131747-45-0).

(4-Bromopyridin-2-yl)methanol (cas: 131747-45-0) 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.Recommanded Product: 131747-45-0

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

The synthesis of piperidine nucleoside analogs-a comparison of several methods to access the introduction of nucleobases was written by Kovackova, Sona;Dracinsky, Martin;Rejman, Dominik. And the article was included in Tetrahedron in 2011.Formula: C10H17NO2 This article mentions the following:

This work deals with the synthesis of piperidine and hydroxypiperidine analogs of nucleosides, e.g. I. Starting from com. available 3-hydroxypiperidine, proline or 4-hydroxyproline, a series of piperidine derivatives of both purine and pyrimidine nucleobases was prepared Various methods of nucleobase attachment were evaluated. The prepared compounds were tested for cytostatic, antibacterial, and antiviral properties but no significant activity was found. In the experiment, the researchers used many compounds, for example, tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (cas: 85838-94-4Formula: C10H17NO2).

tert-Butyl 5,6-dihydropyridine-1(2H)-carboxylate (cas: 85838-94-4) 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. 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. Formula: C10H17NO2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Microwave-promoted syntheses of pyridine carboxamides and tert-carboximides from novel 6-acetylpyridine-2-carboxylic acid was written by Su, Biyun;Zhao, Jianshe;Zhang, Qunzheng;Qin, Wenlong. And the article was included in Synthetic Communications in 2009.Recommanded Product: 122637-39-2 This article mentions the following:

A novel 6-acetylpyridine-2-carboxylic acid was obtained during the synthesis of Et 6-acetylpyridine-2-carboxylate from 2,6-dipicolinic acid. 6-Acetylpyridine-2-carboxylic acid reaction with one or two equivalent of aromatic amines under microwave irradiation resulting in pyridine carboxamides and pyridine carboximides, resp. In the experiment, the researchers used many compounds, for example, 6-Acetylpicolinic acid (cas: 122637-39-2Recommanded Product: 122637-39-2).

6-Acetylpicolinic acid (cas: 122637-39-2) 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. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Recommanded Product: 122637-39-2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem