Month: December 2022

Vanhoenacker, Gerd published the artcileDetermination of arylamines and aminopyridines in pharmaceutical products using in-situ derivatization and liquid chromatography-mass spectrometry, Related Products of pyridine-derivatives, the publication is Journal of Chromatography A (2009), 1216(16), 3563-3570, database is CAplus and MEDLINE.

Arylamines and aminopyridines form a class of potentially genotoxic impurities (PGIs) that can be present at trace levels in active pharmaceutical ingredients (APIs). A generic method was developed that allows the anal. of a selected set of these solutes at sub-ppm level relative to the drug substance. A highly concentrated solution of the pharmaceutical compound is analyzed by LC-MS using a single quadrupole mass spectrometer in the selected ion monitoring (SIM) mode. Since a number of target compounds show little or no retention in the reversed-phase LC setup, a fast and simple derivatization procedure using hexylchloroformate was applied. The amide derivatives of the PGI result in a higher mol. weight (more specific ion for SIM) and better chromatog. behavior. The methodol., consisting of a dual run on resp. a non-derivatized and a derivatized sample, was validated and applied to a selection of pharmaceutical substances. The method was found to be sufficiently sensitive and robust and is applicable in a QA/QC environment.

Journal of Chromatography A 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 C15H12O8, Related Products of pyridine-derivatives.

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

Chung, Yongseog published the artcileStructural effects controlling the rate of the retro-Diels-Alder reaction in anthracene cycloadducts, Computed Properties of 107263-95-6, the publication is Journal of Organic Chemistry (1989), 54(5), 1018-32, database is CAplus.

A fairly broad study of how the structure of an anthracene cycloadduct affects the rate of its cycloreversion reaction was undertaken. Conclusions were drawn based on the rate constants for retro-Diels-Alder (rDA) reactions of a variety of anthracene-type adducts conducted in di-Ph ether. The rDA reaction of anthracene cycloadducts is influenced by diene substituents in the following ways: (1) electron-donating groups increase the reaction rate, and the accelerating effect is subject to geometric modulation for a conjugating substituent like dimethylamino; (2) electron-withdrawing groups may decrease or increase the reaction rate, although the effect is rarely large; and (3) steric acceleration is relatively small and demonstrates an unprecedented bell-shaped structure-reactivity profile. Peripheral substitution of the adduct with siloxy groups results in a significant acceleration, even though the groups are three bonds removed from the reaction site. The same reaction is influenced by dienophile substituents in the following ways: (1) electron-withdrawing groups increase the rate of the reaction; (2) strongly conjugating substituents make the reaction much faster than predicted by classical electron-withdrawing or -donating ability due to a change to polar mechanism; and (3) there is no observable steric effect.

Journal of Organic Chemistry published new progress about 107263-95-6. 107263-95-6 belongs to pyridine-derivatives, auxiliary class Fluorination reagent, name is 1-Fluoropyridiniumtriflate, and the molecular formula is C6H5F4NO3S, Computed Properties of 107263-95-6.

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

Jiang, Rong published the artcile3,5-Disubstituted quinolines as novel c-Jun N-terminal kinase inhibitors, COA of Formula: C5H6BNO2, the publication is Bioorganic & Medicinal Chemistry Letters (2007), 17(22), 6378-6382, database is CAplus and MEDLINE.

The structure-based design and synthesis of a novel series of c-Jun N-terminal kinase (JNK) inhibitors with selectivity against p38 is reported. The unique structure of these 3,5-disubstituted quinolines, e.g. I, was developed from the previously reported 4-(2,7-phenanthrolin-9-yl)phenol. The X-ray crystal structure of I in JNK3 reveals an unexpected binding mode for this new scaffold with protein.

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 C5H6BNO2, COA of Formula: C5H6BNO2.

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

Deau, Emmanuel published the artcileMicrowave-assisted synthesis of novel N-(4-phenylthiazol-2-yl)-benzo[d]thiazole-, thiazolo[4,5-b]pyridine-, thiazolo[5,4-b]pyridine- and benzo[d]oxazole-2-carboximidamides inspired by marine topsentines and nortopsentines, Synthetic Route of 39856-58-1, the publication is Tetrahedron (2014), 70(35), 5532-5540, database is CAplus.

We report the synthesis of novel N-(4-phenylthiazol-2-yl)-substituted benzo[d]thiazole-, thiazolo[4,5-b]pyridine-, thiazolo[5,4-b]pyridine- and benzo[d]oxazole-2-carboximidamides, which were inspired by marine topsentines and nortopsentines. Condensation of 4,5-dichloro-1,2,3-dithiazolium chloride (Appel salt) with various ortho-halogenated anilines, aminopyridines and aminophenols gave the corresponding aryliminodithiazoles in good to excellent yields. Copper(I)-mediated or nucleophilic-assisted cyclization of aryliminodithiazoles furnished cyano-functionalized benzo[d]thiazoles, thiazolo[4,5-b]- and thiazolo[5,4-b]-pyridines and benzo[d]oxazoles. The latter were condensed with substituted 4-phenylthiazol-2-amines to furnish twenty seven new polyaromatic carboximidamides in moderate to good yields.

Tetrahedron published new progress about 39856-58-1. 39856-58-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Bromide,Amine, name is 2-Bromopyridin-3-amine, and the molecular formula is C5H5BrN2, Synthetic Route of 39856-58-1.

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

Moser, Daniel published the artcileSelective Functionalization of Aminoheterocycles by a Pyrylium Salt, Safety of 4-Amino-2-picoline, the publication is Angewandte Chemie, International Edition (2018), 57(34), 11035-11039, database is CAplus and MEDLINE.

The functionalization of aminoheterocycles by using a pyrylium tetrafluoroborate reagent (Pyry-BF₄) is presented. This reagent efficiently condenses with a great variety of heterocyclic amines and primes the C-N bond for nucleophilic aromatic substitution. More than 60 examples for the formation of C-O, C-N, C-S, or C-SO₂R bonds are disclosed herein. In contrast to C-N activation through diazotization and polyalkylation, this method is characterized by its mild conditions and impressive functional-group tolerance. In addition to small-mol. derivatization, Pyry-BF₄ allows the introduction of functional groups in a late-stage fashion to furnish highly functionalized structures.

Angewandte Chemie, International Edition 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, Safety of 4-Amino-2-picoline.

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

Zhang, Jin published the artcileSelective Oxidation of Alkylarenes to the Aromatic Ketones or Benzaldehydes with Water, Recommanded Product: Phenyl(pyridin-2-yl)methanone, the publication is Organic Letters (2022), 24(5), 1152-1157, database is CAplus and MEDLINE.

Here a palladium-catalyzed oxidation method for converting alkylarenes into the aromatic ketones or benzaldehydes ArC(O)R¹ [Ar = Ph, 4-MeC₆H₄, 4-HOC₆H₄, etc.; R¹ = H, Ph, 4-ClC₆H₄, etc.] with water as the only oxygen donor was reported. This C-H bond oxidation functionalization did not require other oxidants and hydrogen acceptors, and H₂ was the only byproduct. The oxygen atom introduced into the products was confirmed to be from water by the MS anal. on the product of the ¹⁸O-labeled water reaction.

Organic Letters published new progress about 91-02-1. 91-02-1 belongs to pyridine-derivatives, auxiliary class Pyridine,Benzene,Ketone, name is Phenyl(pyridin-2-yl)methanone, and the molecular formula is C8H6ClF3, Recommanded Product: Phenyl(pyridin-2-yl)methanone.

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

Kort, Michael E. published the artcileDiscovery and Biological Evaluation of 5-Aryl-2-furfuramides, Potent and Selective Blockers of the Na_v1.8 Sodium Channel with Efficacy in Models of Neuropathic and Inflammatory Pain, Application of 4-Amino-2-picoline, the publication is Journal of Medicinal Chemistry (2008), 51(3), 407-416, database is CAplus and MEDLINE.

Na_v1.8 (also known as PN3) is a tetrodotoxin-resistant (TTx-r) voltage-gated sodium channel (VGSC) that is highly expressed on small diameter sensory neurons and has been implicated in the pathophysiol. of inflammatory and neuropathic pain. Recent studies using an Na_v1.8 antisense oligonucleotide in an animal model of chronic pain indicated that selective blockade of Na_v1.8 was analgesic and could provide effective analgesia with a reduction in the adverse events associated with nonselective VGSC blocking therapeutic agents. A series of 5-substituted 2-furfuramides, which are potent, voltage-dependent blockers of the human Na_v1.8 channel were prepared and characterized. Selected derivatives, e.g. the N-tolylfurancarboxamide I and the N-(dimethoxyphenyl)furancarboxamide II, also blocked TTx-r sodium currents in rat dorsal root ganglia neurons with comparable potency and displayed >100-fold selectivity vs. human sodium (Na_v1.2, Na_v1.5, Na_v1.7) and human ether-a-go-go (hERG) channels. Following systemic administration, I and II dose-dependently reduced neuropathic and inflammatory pain in exptl. rodent models.

Journal of Medicinal 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, Application of 4-Amino-2-picoline.

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

Cory, Joseph G. published the artcileSubstituted 2-acylpyridine-α-(N)-hetarylhydrazones as inhibitors of ribonucleotide reductase activity and L1210 cell growth, Quality Control of 2215-33-0, the publication is Anticancer Research (1994), 14(3A), 875-9, database is CAplus and MEDLINE.

A series of substituted 2-acylpyridine-α-(N)-hetarylhydrazones was prepared and studied for their effects on mammalian ribonucleotide reductase activity using a highly purified enzyme preparation from Ehrlich tumor cells and on mouse leukemia L1210 cell growth in culture. Pyridine-2-aldehyde-2-pyridylhydrazone (PH 22), ethyl-2-pyridylketone-1-phthalazinylhydrazone (PH 22-25) and pyridine-2-aldehyde-2′-quinolylhydrazone (PQ 22) inhibited purified ribonucleotide reductase activity and inhibited L1210 cell growth in culture. PH 22-25 inhibited [³H]thymidine incorporation into DNA and inhibited ribonucleotide reductase activity in situ (as measured by [¹⁴C]cytidine metabolism) and as a result inhibited DNA synthesis. There was no effect on RNA synthesis. These data indicate that these substituted hydrazones are potent inhibitors of tumor cell growth through the inhibition of ribonucleotide reductase.

Anticancer Research 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, Quality Control of 2215-33-0.

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

Cook, A. H. published the artcilePreparation of diarylmaleonitriles, Application In Synthesis of 17281-59-3, the publication is Journal of the Chemical Society (1941), 502-6, database is CAplus.

cf. C. and Linstead, C. A. 31, 6237.5. 2,1-HOC₁₀H₆CHO (29 g.) and 15 g. of amalgamated Zn in 300 cc. moist ether, boiled overnight and the product treated with HCl, give 310 mg. of 1,2-bis(2-hydroxy-1-naphthyl)ethylene, m. 252°; di-Me ether (I), m. 222°; both give deep red solutions in concentrated H₂SO₄; light absorption in petr. ether:maximum 3420, 2910 A.; inflection, 2800 A.; E^1%_1cm. 185, 217, 303, resp. The other products are (2,1-HOC₁₀H₆)₂CH₂ and 24 g. of 2,1-HOC₁₀H₆CH₂OH (II). II could not be converted to the bromide or iodide. Addition of 25 g. of 2-C₁₀H₇OMe in 250 cc. AcOH to a solution of 10 g. (HCHO)₃ in 150 cc. AcOH (which had been treated with dry HCl until a clear solution results) and treatment with HCl give, after standing overnight, 21 g. of 2-methoxy-1-chloromethylnaphthalene (III), decomposes at 120° (evolution of HCl); hydrolysis with aqueous NaHCO₃ in Me₂CO gives 2,1-MeOC₁₀H₆CH₂OH. Warming III with dilute EtOH-alkali at 40° for several hrs. gives (2-methoxy-1-naphthyl)-carbinyl Et ether, b₁₂ 173-5°. III (18 g.) in 600 cc. Me₂CO with 12 g. KCN in 300 cc. H₂O at 30-5° gives 16 g. of 2-methoxy-1-naphthaleneacetonitrile (IV), m. 111°. III with AgNO₃ in Me₂CO-EtOH at 30° for 24 h. gives the β-form of I, m. 145°; light absorption in petr. ether: maximum 3380, 2960 A.; inflection 2830 A.; E^1%_1cm. 180, 270, 300, resp. Both forms give orange colors with concentrated H₂SO₄; both are unsaturated toward C(NO₂)₄ but neither is appreciably changed by exposure to UV light in C₆H₆ solution The 2 ethers are probably cis and trans isomers with relative stabilities not infrequently encountered among isomeric stilbenes. IV in CHCl₃ containing CaCO₃ gives a Br derivative, m. 145-6°; this did not react with C₅H₅N. IV does not yield the desired diarylmaleonitrile with Br or I and bases under the most diverse conditions. 2,1-MeC₁₀H₆CH₂Cl (V) and KCN in 85% EtOH give 2-methyl-1-naphthaleneacetonitrile, m. 78°; when more H₂O is used in the reaction, the product is (2-methyl-1-naphthyl)carbinol, m. 137-8°; this loses H₂O at 100° in vacuo but could not be reconverted to V with EtOHHCl at room temperature 2,1-MeOC₁₀H₆CHO yields a cyanohydrin (VI), m. 111°; with SOCl₂ in C₆H₆ at room temperature for 30 min. VI gives bis[(2-methoxy-1-naphthyl)cyanomethyl] ether (VII), m. 121°. When VI or VII is boiled for 20 min. with an excess of SOCl₂, there results 50% of α-chloro-2-methoxy-1-naphthaleneacetonitrile, m. 130°; solution in warm C₅H₅N gives 1-[(2-methoxy-1-naphthyl)-cyanomethyl]pyridinium chloride (VIII), m. 165° (slight decomposition); aqueous Na₂CO₃ gives an orange precipitate of 1-[(2-methoxy-1-naphthyl) cyanomethyl] pyridinium enimine-betaine, m. 150° (decomposition); heating at 200°/0.001 mm. liberates C₅H₅N and gives IV and bis(2-methoxy-1-naphthyl)maleonitrile (IX); passage through Al₂O₃ gives about 5% of the α form, pale yellow, m. 255°, and 5% of the β form, pale yellow, m. 290°; the yield of IX is much smaller on heating VIII. On heating IX with Cu or Cu salts produces results which give intense green colors in C₅H₅N with strong absorption of light at 6250 A. ClCH₂CN and C₅H₅N give the very deliquescent (cyanomethyl)pyridinium chloride (X), m. 178°; aqueous KOH or K₂CO₃ gave the yellow betaine, which easily resinified and could not be crystallized X and Bz₂O in CHCl₃, shaken with aqueous K₂CO₃, give the light yellow Bz derivative of the betaine, m. 145°, identical with Kröhnke’s (ω-cyanophenacyl)pyridinium benzoate (C. A. 33, 2522.9). ClCH₂CONH₂ gives acetamidopyridinium chloride, m. 202-3°; it gives no betaine with alkali. PhClCHCN in C₅H₅N gives (α-cyanobenzyl)pyridinium chloride (XI), m. 159°. The red enimine-betaine, sublimed at 120° in vacuo, gives about 50% of diphenylmaleonitrile; distillation of XI in vacuo gives about 10%. It appears, therefore, that dimerization proceeds only with arylhaloacetonitriles. PhCH₂CH(OH)CN and PCl₅ in C₆H₆, warmed until solution results, give 62% of α-chloro-β-phenylpropionitrile, b₁₃ 128-30°; boiling with quinoline gives PhCH:CHCN in practically quant. yield. PhCH:CH(OH)CN and SOCl₂ give a product b₁₅ 130-40°; this is mainly α-chloro-γ-phenylvinylacetonitrile, but it could not be obtained pure because it continually deposits a compound m. 114°, probably 2,5-diphenyldihydroterephthalonitrile; it yielded no porphyrazine pigment. p-MeOC₆H₄CH(OH)CN (12 g.) and 10% excess of SOCl₂ give 7 g. of (p-methoxyphenyl)-chloroacetonitrile (XII), b₁₃ 153-5°; sublimation of the residue in the distillation flask in vacuo gives bis(p-methoxyphenyl)maleonitrile, m. 186-7°; this also is formed by the direct action of C₅H₅N on XII. A C₅H₅N solution of the melt obtained on heating with Fe at 300° is an intense green color and showed characteristic porphyrazine spectral absorption bands (6320, 5800 A.).

Journal of the Chemical Society published new progress about 17281-59-3. 17281-59-3 belongs to pyridine-derivatives, auxiliary class Pyridine,Nitrile,Salt, name is 1-(Cyanomethyl)pyridin-1-ium chloride, and the molecular formula is C7H7ClN2, Application In Synthesis of 17281-59-3.

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

Gausas, Laurynas published the artcileEvaluation of Manganese Catalysts for the Hydrogenative Deconstruction of Commercial and End-of-Life Polyurethane Samples, Category: pyridine-derivatives, the publication is ChemSusChem (2022), 15(1), e202101705, database is CAplus and MEDLINE.

Polyurethane (PU) is a thermoset plastic that is found in everyday objects, such as mattresses and shoes, but also in more sophisticated materials, including windmills and airplanes, and as insulation materials in refrigerators and buildings. Because of extensive inter-cross linkages in PU, current recycling methods are somewhat lacking. In this work, the effective catalytic hydrogenation of PU materials is carried out by applying a catalyst based on the earth-abundant metal manganese, to give amine and polyol fractions, which represent the original monomeric composition In particular, Mn-^PhMACHO is found to catalytically deconstruct flexible foam, molded foams, insulation, and end-of-life materials at 1 weight% catalyst loading by applying a reaction temperature of 180°C, 50 bar of H₂, and 0.9 weight% of KOH in iso-Pr alc. The protocol is showcased in the catalytic deconstruction of 2 g of mattress foam using only 0.13 weight% catalyst, resulting in 90% weight recovery and a turnover number of 905.

ChemSusChem 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 C23H43NP2, Category: pyridine-derivatives.

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