Tag: M.W=100-150

Tamura, Masazumi published the artcileCeO₂-catalyzed nitrile hydration to amide: reaction mechanism and active sites, Formula: C6H3FN2, the publication is Catalysis Science & Technology (2013), 3(5), 1386-1393, database is CAplus.

CeO₂ acted as a reusable and effective catalyst for the hydration of various nitriles to amides in water, under neutral conditions at low temperature (30-100 °C). To identify the active site, we examined the relationship between activity and the amount of the pair site of a low-coordinated Ce site (Ce_LC) (oxygen defect site) and adjacent Lewis base (exposed oxygen), determined by methanol adsorption on FTIR. It is revealed that the Ce_LC-O site is the active site for the reaction. To clarify the reaction mechanism, we carried out in situ FTIR studies on the reaction of acetonitrile with surface Ce-OH groups and kinetic studies such as H₂O/D₂O kinetic isotope effect and Hammett plot. The results give the following catalytic cycle: (1) dissociation of H₂O on the Ce_LC-O site (oxygen defect site) to give OH^δ- and H^δ+ species on the site, (2) formation of an adsorption complex between nitrile and CeO₂, (3) addition of OH^δ- to the carbon atom of the cyano group of the complex and (4) desorption of the amide from the CeO₂ surface, accompanying a regeneration of the Ce_LC-O site. On the basis of the above fundamental information, we found a simple method for activity increase; preheating of CeO₂ at 600 °C resulted in desorption of surface carbonate, and the exposed Ce_LC-O site thus prepared showed one order of magnitude higher activity for the hydration of various nitriles than untreated CeO₂.

Catalysis Science & Technology 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 C9H5ClO2, Formula: C6H3FN2.

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

Ceccarelli, Simona M. published the artcileMetabolite identification via LC-SPE-NMR-MS of the in vitro biooxidation products of a lead mGlu5 allosteric antagonist and impact on the improvement of metabolic stability in the series, Name: 4-Amino-2-picoline, the publication is ChemMedChem (2008), 3(1), 136-144, database is CAplus and MEDLINE.

Detailed information on the metabolic fate of lead compounds can be a powerful tool for an informed approach to the stabilization of metabolically labile compounds in the lead optimization phase. The combination of high performance liquid chromatog. (HPLC) with NMR spectroscopy and mass spectrometry (MS) has been used to give comprehensive structural data on metabolites of novel drugs in development. Recently, increased automation and the embedding of online solid-phase extraction (SPE) into a integrated LC-SPE-NMR-MS system have improved enormously the detection limits of this approach. The new technol. platform allows the anal. of complex mixtures from microsome incubations, combining low material requirements with relatively high throughput. Such characteristics make it possible to thoroughly characterize metabolites of selected compounds at earlier phases along the path to lead identification and clin. candidate selection, thus providing outstanding guidance in the process of eliminating undesired metabolism and detecting active or potentially toxic metabolites. Such an approach was applied at the lead identification stage of a backup program on metabotropic glutamate receptor 5 (mGlu5) allosteric inhibition. The major metabolites of a lead (I) were synthesized and screened, revealing significant in vitro activity and possible involvement in the overall pharmacodynamic behavior of I. The information collected on the metabolism of the highly active compound I was pivotal to the synthesis of related compounds with improved microsomal stability.

ChemMedChem 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 C6H8N2, Name: 4-Amino-2-picoline.

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

Urban, R. published the artcileAminomethoxypyridines and corresponding sulfanilamides, Application of 4-Amino-2-picoline, the publication is Helvetica Chimica Acta (1964), 47(2), 363-79, database is CAplus.

A number of 2-, 3-, and 4-sulfanilamidopyridines containing substituents in the pyridine ring, particularly all still unknown monomethoxy derivatives, were prepared for pharmacol. evaluation. To 10 g. Na in 185 mL. absolute MeOH was added 20 g. 2-amino-4-chloropyridine and a little Cu powder, the whole heated 12 h. at 150° in a sealed tube, cooled, diluted with H₂O, filtered, and evaporated, the residue dissolved in H₂O, and the product extracted with Et₂O to give 10.6 g. 2-amino-4-methoxypyridine, m. 115-16° (C₆H₆). 2-Chloro-4-nitropyridine (16 g.), 32 g. Fe powder, and 500 mL. AcOH heated gradually with stirring until the reaction became brisk, when the reaction subsided the mixture heated 1 h. at 100°, cooled, and worked up gave 10.4 g. 4-amino-2-chloropyridine (I), m. 87-9° (C₆H₆-petr. ether). To 5.0 g. Na in 90 mL. absolute MeOH was added 10 g. I and a little Cu powder and the mixture heated 10 h. at 150° in a sealed tube, and worked up to give 5.4 g. 4-amino-2-methoxypyridine, m. 88-9° (C₆H₆-petr. ether, sublimation at 60°/0.1 mm.); Ac derivative m. 96-7° (C₆H₆). 5-Hydroxy-2-phenylazopyridine (II) in 400 mL. tert-BuOH added dropwise during 4 h. to 11 g. CH₂N₂ in 1.7 l. Et₂O at – 15 to -10° with stirring, the solution allowed to reach room temperature and evaporated, the residue dissolved in C₆H₆, the solution worked up, and the partially crystalline product chromatographed on Al₂O₃ (activity II) with C₆H₆ gave 14.8 g. 5-MeO analog (III) of II, m. 72-3° (petr. ether). III (10 g.) in 220 mL. MeOH and 55 mL. 3N HCl hydrogenated over 10 g. 10% Pd-C (the calculated amount H was absorbed in 8 h.) and the solution filtered, concentrated, and worked up gave 4.1 g. 2-amino-5-methoxypyridine, b₁₀ 128-30°, m. 36-8°; Ac derivative (IV) m. 102-3° (C₆H₆-petr. ether); HCl salt m. 145-6° (MeOH-Et₂O). Ac₂O (2.9 mL.) added dropwise to 2.5 g. 2-amino-3-methoxypyridine (V) in 5.0 mL. anhydrous C₅H₅N at below 0° with stirring and worked up gave 2.9 g. Ac derivative of V, m. 102-3° (C₆H₆-petr. ether, C₆H₆ or EtOAc), mixed m.p. (with IV) 70°. 5-Bromonicotinic acid NH₄ salt (270 g.) in 2 1. 25% aqueous NH₃ heated 10 h. at 180° with 100 g. CuO in an autoclave, the filtered solution concentrated and treated with aqueous Cu(OAc)₂, the precipitated Cu salt filtered and dissolved in dilute HCl, the solution treated with H₂S, filtered, and evaporated, the residue dissolved in dilute aqueous NaOH, and the solution neutralized with dilute HCl gave 104 g. 5-aminonicotinic acid (VI), m. 295-6° (decomposition) (H₂O). VI (20 g.) suspended in 400 mL. absolute MeOH saturated with HCl with ice-cooling, and the resulting solution refluxed 0.5 h. while continuously introducing HCl and cooled gave (in 2 crops) 23.8 g. Me 5-hydroxynicotinate-HCl (VII.-HCl), m. 194-6° (decomposition); 73% VII m. 192-3° (H₂O). VII (8.0 g.) in 200 mL. tert-BuOH added dropwise during 6 h. to 3.5 g. CH₂N₂ in 350 mL. Et₂O at – 15 to – 10° with stirring, the solution stirred several hrs. with cooling, allowed to reach room temperature, filtered, and concentrated, the residue dissolved in alc.-HCl, and the solution evaporated gave, after crystallization from MeOH-Et₂O, 9.5 g. Me 5-methoxynicotinate-HCl (VIII.HCl), which in aqueous solution passed through a column of Amberlite IR-45 and the effluent evaporated gave 5.0 g. VIII, m. 61-2° (sublimation at 40°/0.1 mm.), saponification giving 5-methoxynicotinic acid (IX), m. 228-9°. VIII (8.0 g.), 18 mL. 100% N₂H₄.H₂O, and 25 mL. MeOH refluxed 6 h. and cooled gave 6.8 g. hydrazide (X) of IX, m. 157-8° (MeOH). X (19.4 g.) in 125 mL. N HCl treated dropwise with 12 g. KNO₂ in 40 mL. H₂O at 5° with stirring and ice-cooling, the precipitated azide filtered off, washed with a little H₂O, dried over P₂O₅, and refluxed 1 h. in 200 mL. absolute EtOH, and the solution evaporated gave 20.8 g. 5-methoxy-3-pyridinecarbamic acid Me ester, m. 139-41°, which refluxed with 40 g. Ba(OH)₂ in 400 mL. H₂O, the solution cooled, saturated with CO₂, filtered, and worked up gave 8.0 g. 3-amino-5-methoxypyridine, b₁₅ 166-8°, m. 64-5° (C₆H₆); Ac derivative m. 133-4° (C₆H₆, EtOAc); HCl salt m. 205-7° (decomposition). Nicotinic acid-HCl (280 g.) and 500 mL. SOCl₂ refluxed 6 days and then heated 12 h. at 180° in an autoclave, the mixture added to H₂O, heated to boiling, and filtered hot, the filtrate cooled, and the precipitate recrystallized from H₂O with C gave 130 g. mixture of 5-chloro- (XI) and 5,6-dichloronicotinic acid, which refluxed 4 h. with 52 g. red P and 130 g. KI in 800 mL. 57% HI, the solution cooled, diluted with H₂O, filtered, concentrated to small volume, and treated with an appropriate amount aqueous Na₂CO₃ gave 78 g. XI, m. 167-8° (H₂O); Me ester m. 87-8°; hydrazide (XII) m. 176-8°. XII (20 g.) dissolved in 120 mL. N HCl by heating, the solution cooled in ice, treated dropwise with 12 g. KNO₂ in 40 mL. H₂O at 5° with stirring, the precipitated azide filtered off, washed with H₂O, heated 0.5 h. on a water bath in 220 mL. 50% AcOH, cooled, made alk. with aqueous NaOH, and cooled, and the product isolated with Et₂O gave 6.0 g. 3-amino-5-chloropyridine, m. 78-9° (sublimation at 60°/0.1 mm., C₆H₆-petr. ether). The above azide dried over P₂O₅ and refluxed 1 h. with 10 volumes absolute EtOH gave 5-chloro-3-pyridinecarbamic acid Et ester, m. 149-51° (MeOH, sublimation at 70°/0.1 mm.). Na (5 g.) in 60 mL. MeOH and 16.2 g. 4,6-dichloro-2-picoline heated 12 h. at 130-40° in a sealed tube, cooled, and diluted with Et₂O, and the solution filtered and fractionated gave 11.8 g. 4,6-dimethoxy-2-picoline (XIII), b₁₇ 87-8°, n²³_D 1.5076, m. 19-20°. XIII (11.7 g.) in 350 mL. H₂O heated on a water bath, 13 g. finely powd. KMnO₄ added with stirring, when the violet color disappeared 12.5 g. KMnO₄ and 70 mh H₂O added, the mixture heated 2.5 h., cooled a little, the MnO₂ filtered off and washed with hot H₂O, the combined cooled filtrates extracted with Et₂O (6 g. XIII recovered), acidified with HCl, and evaporated, the residue (XIV) extracted (Soxhlet) exhaustively with C₆H₆, and the extract evaporated gave 1.2 g. 4,6-dimethoxypicolinic acid (XV), m. 145-7° (C₆H₆, sublimation at 90°/0.1 mm.). It was preferable not to isolate XV, but to convert XIV directly into the Me ester (XVI) of XV (20% yield). XV (1.2 g.) in 40 mL. absolute MeOH saturated with HCl with ice-cooling, the solution evaporated, the residue extracted with Et₂O, and the extract worked up gave 1.1 g. XVI, m. 108-9° (C₆H₆, sublimation at 60°/0.1 mm.). Na (3.3 g.) in 50 mL. absolute MeOH refluxed 8 h. with 10.0 g. Me 4,6-dichloropicolinate and a little Cu powder, the filtered solution evaporated, and the residue extracted with Et₂O gave 4.8 g. XVI, m. 106-8°. XVI (18 g.) in 100 mL. MeOH treated with 33 mL. 100% N₂H₄.H₂O gave 17 g. hydrazide (XVII) of XV, m. 156-7° (MeOH). H₂O (35 mL.) containing 8.0 g.

Helvetica Chimica Acta 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 C15H20O6, Application of 4-Amino-2-picoline.

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

Schaffner, Arnaud-Pierre published the artcilePhosphinanes and Azaphosphinanes as Potent and Selective Inhibitors of Activated Thrombin-Activatable Fibrinolysis Inhibitor (TAFIa), Application of 2-Pyridinylboronic acid, the publication is Journal of Medicinal Chemistry (2021), 64(7), 3897-3910, database is CAplus and MEDLINE.

Selective and potent inhibitors of activated thrombin activatable fibrinolysis inhibitor (TAFIa) have the potential to increase endogenous and therapeutic fibrinolysis and to behave like profibrinolytic agents without the risk of major hemorrhage, since they do not interfere either with platelet activation or with coagulation during blood hemostasis. Therefore, TAFIa inhibitors could be used in at-risk patients for the treatment, prevention, and secondary prevention of stroke, venous thrombosis, and pulmonary embolisms. In this paper, we describe the design, the structure-activity relationship (SAR), and the synthesis of novel, potent, and selective phosphinanes and azaphosphinanes as TAFIa inhibitors. Several highly active azaphosphinanes display attractive properties suitable for further in vivo efficacy studies in thrombosis models.

Journal of Medicinal Chemistry 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, Application of 2-Pyridinylboronic acid.

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

Bagherzadeh, Nastaran published the artcileSustainable and recyclable magnetic nanocatalyst of 1,10-phenanthroline Pd(0) complex in green synthesis of biaryls and tetrazoles using arylboronic acids as versatile substrates, Application of 2-Pyridinylboronic acid, the publication is Molecular Catalysis (2021), 111489, database is CAplus.

A magnetic nanocatalyst was purveyed as a heterogeneous recoverable palladium-based catalyst anchored on green, sustainable and phosphine free support. Resulted Fe3O4@SiO2-Phen-Pd(0) nanocatalyst bearing powerful phenanthroline ligand was thoroughly characterized by physicochem. approaches like UV-vis, FT-IR, EDX, XRD, TGA, ICP, VSM, DLS, FESEM, and TEM analyses. After finding trustable data, the obtained magnetic catalyst was considered to be applied in the Suzuki-Miyaura type C-C couplings and getting corresponding tetrazoles using arylboronic acid derivatives as alternate precursors of aromatic halides and stupendous data were observed

Molecular Catalysis 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, Application of 2-Pyridinylboronic acid.

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

Gavhane, Dinesh S. published the artcileNano Copper Catalyzed Microwave Assisted Coupling of Benzene Boronic Acids with Thiophenols, Category: pyridine-derivatives, the publication is Letters in Organic Chemistry (2019), 16(6), 491-494, database is CAplus.

A proficient, microwave mediated methodol. using CuFe₂O₄ nanoparticle as the catalyst for S-arylation of substituted benzene boronic acids with thiophenol was developed. In this method, the substituted thioethers were easily obtained through a C-S bond formation using microwave irradiation technique as well as conventional heating in the presence of CuFe₂O₄ nanoparticles with modest to excellent yields with the less reaction time. The ligand free microwave technique helped in the preparation of substituted thioethers in measurable amount within 10 mins. The same results were obtained with conventional heating in 12h. The reported method was economically efficient and an alternative to the initial existing method for the preparation of substituted thioethers.

Letters in Organic Chemistry 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, Category: pyridine-derivatives.

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

Zeng, Qingbei published the artcileSynthesis and SAR studies of benzimidazolone derivatives as histamine H₃-receptor antagonists, Related Products of pyridine-derivatives, the publication is Bioorganic & Medicinal Chemistry Letters (2013), 23(21), 6001-6003, database is CAplus and MEDLINE.

A novel series of benzimidazolone-containing histamine H₃-receptor antagonists were prepared and their structure-activity relationship was explored. These benzimidazolone analogs demonstrate potent H₃-receptor binding affinities, no P 450 enzyme inhibition, and strong H₃ functional activity. Compound I exhibits the best overall profile with H₃K_i = 0.95 nM and rat AUC = 12.9 μM h.

Bioorganic & Medicinal Chemistry Letters 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 C19H21N3O3S, Related Products of pyridine-derivatives.

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

Malarski, Z. published the artcileDielectric and spectroscopic studies of pentachlorophenol-amine complexes, Recommanded Product: 4-Amino-2-picoline, the publication is Journal of Physical Chemistry (1982), 86(3), 401-6, database is CAplus.

Dipole moments in CCl₄, IR absorption spectra under various conditions, and UV spectra of a number of pentachlorophenol (PCP) complexes with N bases were measured over a broad ΔpK_a range. From the dipole moment measurements an inversion region of ΔpK_a was found for which a 50% proton transfer can be expected. The complexes from this region exhibit certain anomalies in their IR spectra, in particular a broad continuous absorption, a strong temperature effect on the absorption in the far-IR, and particular sensitivity to changes in solvent polarity. The UV spectra revealed proton-transfer equilibrium for a number of complexes, both in solutions and in the solid state.

Journal of Physical Chemistry 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 C6H8N2, Recommanded Product: 4-Amino-2-picoline.

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

Aharon, Cheryl published the artcileUsing fluoroform for constructing aromatic and heterocyclic trifluoromethylselenyl compounds, Recommanded Product: 2-Pyridinylboronic acid, the publication is Journal of Fluorine Chemistry (2021), 109866, database is CAplus.

Fluoroform is used to prepare CuCF₃ according to literature procedures. This nucleophilic trifluoromethyl moiety was reacted with aromatic and heterocyclic selenium cyanide derivatives 3-R-4-N(R₁)(R₂)-5-R³C₆H₂SeCN (R = H, Me, Br; R¹ = H, Et, Ac; R² = H, Et, Ac; R³ = H, Me), 3-R⁴-4-R⁵-C₆H₃SeCN (R⁴ = H, Me; R⁵ = Me, t-Bu, Cl, etc.), I (R⁶ = H, Br; R⁷ = H, SeCN; R⁸ = H, SeCN) and II (X = O, S) resp. to form the corresponding trifluoromethylselenium compounds 3-R-4-N(R₁)(R₂)-5-R³C₆H₂SeCF₃, 3-R⁴-4-R⁵-C₆H₃SeCF₃, III (R⁹ = H, SeCF₃; R¹⁰ = H, SeCF₃) and IV. Selenium cyanides were made with 1,3-dicyanotriselenide prepared in situ from malononitrile and selenium dioxide. The electrophilicity of the reagent (^δ+SeCN) was enough to attack aniline derivatives 3-R-4-N(R₁)(R₂)-5-R³C₆H₃ at the para position, but with other aromatics it was advantageous to use the corresponding boronic acids 3-R⁴-4-R⁵-C₆H₃B(OH)₂, V (R¹¹ = H, B(OH)₂; R¹² = H, B(OH)₂) and VI as the moiety was easily displaced by the selenium cyanate moiety.

Journal of Fluorine Chemistry 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, Recommanded Product: 2-Pyridinylboronic acid.

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

Lavit, Kseniya published the artcileZooming in on the hydrated imidazoline ring expansion: Factors influencing the rate of N â†?N’ aroyl migration in N-aroyl-N-(hetero)aryl ethylenediamines, Related Products of pyridine-derivatives, the publication is Tetrahedron Letters (2020), 61(42), 152423, database is CAplus.

The influence of electronic factors on the rates of N â†?N’ aroyl migration in N-aroyl-N-(hetero)aryl ethylenediamines was examined Electron-withdrawing substituents on the aroyl group weakly accelerate the reaction (in linear correlation with the Hammett σ_p constants). Much stronger influence came from the nitrogen-bound aromatic group which gave a strong linear correlation with the Hammett σ^–_p constants For electron-deficient heteroaromatics and nitroaroms., the migration was nearly instantaneous in basic medium. These findings will significantly impact the planning of mechanistically related transformations of N-(2-aminoethyl) lactams through the hydrated imidazoline ring expansion (HIRE) process.

Tetrahedron Letters 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, Related Products of pyridine-derivatives.

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