Category: pyridine-derivatives

Griswold, Jessica A. published the artcileStereoconvergent Conjugate Addition of Arylboronic Acids to α-Angelica Lactone Derivatives: Synthesis of Stereochemically Complex γ-Butyrolactones, Category: pyridine-derivatives, the publication is ACS Catalysis (2019), 9(12), 11614-11618, database is CAplus and MEDLINE.

Catalyzed stereoconvergent 1,4-additions to unsaturated carbonyls are rare but of high potential value. This letter details the development of enantioselective arylation reactions of boronic acids and β,γ-butenolides. These reactions are catalyzed by com. available hydroxy[(S)-BINAP]-rhodium(I) dimer to afford stereochem. complex γ-butyrolactone derivatives The reaction products provide functionality amenable to further manipulation and can lead to products with up to three contiguous stereocenters. The reaction proceeds under a dynamic kinetic resolution manifold by isomerizing the achiral starting material into an interconverting mixture of enantiomeric conjugate acceptors, followed by catalyst-controlled, enantiomer-selective 1,4-additionBase-promoted racemization of the intermediate α,β-butenolide is possible due to the high kinetic and thermodn. acidity of the γ-proton.

ACS Catalysis published new progress about 612845-44-0. 612845-44-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester,Ether,Boronic Acids,Boronic acid and ester, name is (6-Ethoxypyridin-3-yl)boronic acid, and the molecular formula is C7H10BNO3, Category: pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Shah, Sonya C. published the artcileCovalent modification of cytochrome c with a hydrazone complex of platinum(II), COA of Formula: C11H10N4, the publication is Journal of the Serbian Chemical Society (1988), 53(3), 139-48, database is CAplus.

The complex Pt(sbpaphy)Cl^– (where sbpaphy is 2-(3-sulfobenzoyl)-pyridine-2-aldehyde 2′-pyridylhydrazone) modifies selectively the histidine (His) 33 residue in horse heart cytochrome c at pH 7.0. The reaction takes place under mild conditions and the Pt(sbpaphy)His label is stable at pH 7.0. The binding site is identified by UV-vis spectrophotometry and by studies of model complexes. The labeled protein is purified readily by cation-exchange chromatog. and the inorganic chromophore in it is quantitated easily owing to its strong UV absorption bands. Cyclic voltammetry, differential-pulse voltammetry, and UV-vis spectrophotometry show that labeling does not perturb the protein.

Journal of the Serbian Chemical Society published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C6H17NO3Si, COA of Formula: C11H10N4.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Shaffer, David W. published the artcileReactivity of a Series of Isostructural Cobalt Pincer Complexes with CO₂, CO, and H⁺, Product Details of C23H43NP2, the publication is Inorganic Chemistry (2014), 53(24), 13031-13041, database is CAplus and MEDLINE.

The preparation and characterization of a series of isostructural cobalt complexes [Co(t-Bu)₂P^EPy^EP(t-Bu)₂(MeCN)₂][BF₄]₂ (Py = pyridine, E = CH₂, NH, O, and X = BF₄ (1a–c)) and the corresponding one-electron reduced analogs [Co(t-Bu)₂P^EPy^EP(t-Bu)₂(MeCN)][BF₄] (2a–c) are reported. The reactivity of the reduced cobalt complexes with CO₂, CO, and H⁺ to generate intermediates in a CO₂ reduction to CO and H₂O cycle are described. The reduction of 1a–c and subsequent reactivity with CO₂ was investigated by cyclic voltammetry, and for 1a also by IR spectroelectrochem. The corresponding CO complexes of (2a–c) were prepared, and the Co-CO bond strengths were characterized by IR spectroscopy. Quantum mech. methods (B3LYP-d3 with solvation) were used to characterize the competitive reactivity of the reduced cobalt centers with H⁺ vs. CO₂. By investigating a series of isostructural complexes, correlations in reactivity with ligand electron withdrawing effects are made.

Inorganic Chemistry published new progress about 338800-13-8. 338800-13-8 belongs to pyridine-derivatives, auxiliary class Bis-phosphine Ligands, name is 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, and the molecular formula is C9H10O4, Product Details of C23H43NP2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Butler, Richard N. published the artcileStereoisomerization in heterocyclic hydrazones derived from 2-acylpyridines and their oxidative cyclization with mercury(II) acetate and lead tetraacetate to fused 1,2,4-triazoles and 1,2,3-triazolium systems, Recommanded Product: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, the publication is Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) (1984), 2109-16, database is CAplus.

Fourteen hydrazones I (R = H, Me, Ph; R¹ = 2-pyridyl, 4-O₂NC₆H₄, Ph, 4-BrC₆H₄, 4-MeOC₆H₄, 4-MeC₆H₄), prepared by coupling 2-formyl-, -benzoyl-, or -acetylpyridine with H₂NNHR¹ (R¹ as before), were isolated predominantly as E isomers, when the acyl substituent R was small (H = Me). When R = Ph, significant yield of Z isomers containing an intramol. H bond were also obtained. The structure of E-I (R = R¹ = Ph) was determined by x-ray crystallog. Oxidation reactions of I were not configuration dependent contrary to the report of R. Kuhn and W. Munzig (1952). A common metallo intermediate II, was obtained by oxidation of E– and Z–I (R = H, R¹ = 2-pyridyl) with Hg(OAc)₂. In Pb(OAc)₄ oxidation of the hydrazones, the product controlling factor was the nature of the methine substituent R. For the ketone derivatives I (R â‰?H), oxidation to fused 1,2,3-triazolium systems occurred via a 5-exo–tet cyclization with E- and Z-hydrazones, whereas for aldehyde systems, I (R = H), the oxidation involved dehydration to a nitrilimine and gave products by solvent addition or a 5-endo–dig cyclization to fused 1,2,4-triazolo systems. Thus, Pb(OAc)₄ oxidation of E– or Z–I (R = Ph, R¹ = 4-O₂NC₆H₄) gave 80% triazolopyridinium III, whereas similar oxidation of E– or Z–I (R = H, R¹ = 2-pyridyl) gave 73-86% triazolopyridine IV.

Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C11H10N4, Recommanded Product: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Butler, Richard N. published the artcileDetection of a metalo intermediate and geometrical isomerizations in an oxidative cyclization of a heterocyclic hydrazone with mercury(II) acetate, Name: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, the publication is Journal of the Chemical Society, Chemical Communications (1981), 376-7, database is CAplus.

Oxidative cyclization of the (E)-hydrazone I on treatment with Hg(OAc)₂ (AcOH, 70°, 16 h) gave 37% II, via the (Z)-intermediate III. The reaction mechanism, which involves a series of cis-trans isomerizations, is discussed.

Journal of the Chemical Society, Chemical Communications published new progress about 2215-33-0. 2215-33-0 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine, and the molecular formula is C11H10N4, Name: 2-((2-(Pyridin-2-yl)hydrazono)methyl)pyridine.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Hansen, Marvin M. published the artcileBoronic Acids and Derivatives-Probing the Structure-Activity Relationships for Mutagenicity, Computed Properties of 197958-29-5, the publication is Organic Process Research & Development (2015), 19(11), 1507-1516, database is CAplus.

Despite a recent publication describing boronic acids as a “novel class of bacterial mutagen,” process and anal. chemists may not be aware of the potential worker exposure hazards, or of the need to assess boron compounds as potential genotoxic impurities (GTIs) per ICH M7. This publication provides new Ames data for 44 com. available boronic acids, boronic acid derivatives, and boron-containing reagents. Trends in the Ames data are discussed from a structure-activity perspective. Common reagents such as bis(pinacolato)diboron and bis-boronic acid were shown to be mutagenic in the Ames assay. Currently available in silico computational models were found to provide little value in predicting the outcome of the Ames assay for boronic acids and derivatives The authors propose oxygen-mediated oxidation of boron compounds to generate organic radicals as a potential mechanism for mutagenicity. It is hoped that this paper will result in increased awareness of this class of GTIs and prompt publication of addnl. Ames data for boronic acids and their derivatives that will lead to improved (Q)SAR models and an understanding of the mechanism of mutagenicity.

Organic Process Research & Development published new progress about 197958-29-5. 197958-29-5 belongs to pyridine-derivatives, auxiliary class Pyridine,Boronic acid and ester, name is 2-Pyridinylboronic acid, and the molecular formula is C5H6BNO2, Computed Properties of 197958-29-5.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Guo, Peng-Fei published the artcileC-H Arylation of Pyridines: High Regioselectivity as a Consequence of the Electronic Character of C-H Bonds and Heteroarene Ring, HPLC of Formula: 89076-64-2, the publication is Journal of the American Chemical Society (2011), 133(41), 16338-16341, database is CAplus and MEDLINE.

A new catalytic protocol for highly selective C-H arylation of pyridines containing common and synthetically versatile electron-withdrawing substituents (NO₂, CN, F and Cl) is reported. The new protocol expands the scope of catalytic azine functionalization as the excellent regioselectivity at the 3- and 4-positions well complements the existing methods for C-H arylation and Ir-catalyzed borylation, as well as classical functionalization of pyridines. Another important feature of the new method is its flexibility to adapt to challenging substrates by a simple modification of the carboxylic acid ligand or the use of silver salts. The regioselectivity can be rationalized on the basis of the key electronic effects (repulsion between the nitrogen lone pair and polarized C-Pd bond at C2-/C6-positions and acidity of the C-H bond) in combination with steric effects (sensitivity to bulky substituents).

Journal of the American Chemical Society published new progress about 89076-64-2. 89076-64-2 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitro Compound,Benzene, name is 5-Nitro-2-phenylpyridine, and the molecular formula is C11H8N2O2, HPLC of Formula: 89076-64-2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Moree, Wilna J. published the artcileNovel benzothiophene H₁-antihistamines for the treatment of insomnia, Name: 4-Fluoropicolinonitrile, the publication is Bioorganic & Medicinal Chemistry Letters (2010), 20(7), 2316-2320, database is CAplus and MEDLINE.

SAR of lead benzothiophene H₁-antihistamine I (R = 2-pyridyl) was explored to identify backup candidates with suitable pharmacokinetic profiles for an insomnia program. Several potent and selective H₁-antihistamines with a range of projected half-lives in humans were identified. Had a suitable human half-life as demonstrated in a human microdose study, but variability in pharmacokinetic profile, attributed to metabolic clearance, prevented further development of this compound I (R = 1-pyrazolyl) demonstrated lower predicted clearance in preclin. studies, and may represent a more suitable backup compound

Bioorganic & Medicinal Chemistry Letters published new progress about 847225-56-3. 847225-56-3 belongs to pyridine-derivatives, auxiliary class Pyridine,Fluoride,Nitrile, name is 4-Fluoropicolinonitrile, and the molecular formula is C6H3FN2, Name: 4-Fluoropicolinonitrile.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Jung, Ju young published the artcileEnhanced Solubility Through Particle Size Control, Modification of Crystal Behavior, and Crystalline Form Changes in Solid Dispersion of Nifedipine, Related Products of pyridine-derivatives, the publication is Biotechnology and Bioprocess Engineering (2022), 27(1), 105-110, database is CAplus.

The purpose of this study was to investigate the selectivity of polymers and the suitability of spray drying to enhance nifedipine solubility Nifedipine alone or in combination with polymers was dissolved in a mixed solvent of methylene chloride and ethanol. The hydrophilic polymers used were PVP K-30, HPMC, HPMCP, Eudragit, and HPMCAS. Each solid dispersion was prepared using a laboratory spray dryer. The spray-dried solid dispersants were characterized by SEM, DSC, and XRPD anal., and dissolution tests compared the dissolution rates of nifedipine solid dispersants and nifedipine. The results showed that all spray-dried solid dispersions were in an amorphous form. Dissolution tests were performed at pH 1.2 (artificial gastric juice) and pH 6.8 (artificial intestinal juice) to evaluate solid dispersion solubility The solid dispersion containing HPMC showed a notably enhanced dissolution rate under both pH conditions. Interestingly, HPMCP and HPMCAS showed almost no enhancement of dissolution behavior at pH 1.2, but a significant increase (10 times or higher) over that of the pure polymer at pH 6.8. Solubility enhancement of poorly soluble drugs differs markedly among the polymers used for spray drying. From the results, HPMCP and HPMCAS are suitable as carriers for drugs with poor solubility that require acid resistance.

Biotechnology and Bioprocess Engineering published new progress about 21829-25-4. 21829-25-4 belongs to pyridine-derivatives, auxiliary class Membrane Transporter/Ion Channel,Calcium Channel, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Related Products of pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Yonova, P. A. published the artcileSynthesis of 1,1′-polymethylenebis-(3-substituted) ureas and related compounds of potential biological interest, Quality Control of 18437-58-6, the publication is Dokladi na Bulgarskata Akademiya na Naukite (1999), 52(3-4), 53-56, database is CAplus.

RNHCONH(CH₂)_nNHCONHR [I, R = Ph, 3-FC₆H₄, 4-FC₆H₄, 3-ClC₆H₄, 4-ClC₆H₄, n = 2-6; R = 2-thiazolyl, 4-pyridyl, 4-picolyl, 3,5-dichloro-4-pyridyl, n = 6] were pred. from RNCO and H₂N(CH₂)_nNH₂ or from RNH₂ and H₂N(CH₂)₆NH₂. I have antisenescence activity comparable to that of PhNHCONHPh and putrescine.

Dokladi na Bulgarskata Akademiya na Naukite published new progress about 18437-58-6. 18437-58-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Amine, name is 4-Amino-2-picoline, and the molecular formula is C6H11BF3KO, Quality Control of 18437-58-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem