Tag: M.W=100-150

Walker, Gordon N. published the artcileApplication of sodium borohydride reduction to synthesis of substituted aminopiperidines, aminopiperazines, aminopyridines, and hydrazines, Safety of 4-Amino-2-picoline, the publication is Journal of Organic Chemistry (1961), 2740-7, database is CAplus.

Quaternization of 4-aminopyridine (I) with alkyl and arylalkyl halides gave 4-aminopyridinium salts, which were reduced with NaBH₄ to 1-(alkyl or arylalkyl)-4-aminopiperidines. Both 1-alkyl-4-aminopiperidines and 1-alkyl-4-aminopiperazines could be converted to Schiff bases, which were reduced with NaBH₄ to the corresponding secondary amines. Similar reduction of appropriate Schiff bases as a means of preparing substituted 3-aminopiperidines, aminopyridines, and aminomethylpyridines, as well as reduction of dialkylhydrazones to the corresponding trisubstituted hydrazines were also described. Anhydrous HBr was passed through a cold solution of 33.6 g. veratryl alc. in 500 mL. C₆H₆ 10 min., the lower layer separated, the C₆H₆ treated with Na₂CO₃, stirred, the solution of veratryl bromide (II) filtered, and used in the following step without purification To the C₆H₆ solution of II was added 19 g. I; the mixture refluxed 1.5 h., filtered, and the product crystallized gave 54 g. 1-(3,4-dimethoxybenzyl)-4-aminopyridinium bromide (IIa), m. 248-50° (decomposition), (alc.). A simple two-step synthesis was used in the preparation of the 1,2-diphenylethyl- and 3,4-dimethoxyphenacyl-substituted compounds The remaining substances were prepared from the com. available bromo (in one case, iodo) compounds by the same procedure with a few modifications in solvents used and reaction times. In reactions involving α,ω-dibromoalkanes, a mixture of the compound, 2 equivalents I, and a suitable amount of PhMe was refluxed. The product often settled as an oil. In this case the supernatant was decanted, and the oil crystallized 2-Methyl-4-aminopyridine (III) was most conveniently synthesized by a 2-step reduction of 4-nitro-2-picoline N-oxide as follows. (A) The oxide (45 g.) in 200 mL. alc. containing 4 g. 10% Pd-C shaken under H at 45 lb./sq. in. gave 33 g. 2-methyl-4-aminopyridine N-oxide (IV), yellow crystals, m. 181-3° (alc.). IV (30 g.) in 300 mL. 1:1 AcOH-H₂O treated with excess Zn dust, the mixture warmed 1 h., cooled, covered with Et₂O, treated with a 40% solution of 500 g. NaOH, and the Et₂O solution evaporated gave 16.8 g. III, m. 95° (cyclohexane). The following (4-H₂NC₅H₄N)RBr were obtained (R, solvent prepared in, reflux time in hrs., % yield, and m.p. given): EtO₂CCH₂, C₆H₆-alc., 1.5, 92, 197°; EtO₂CCH₂CH₂, PhMe, 5, 73, 159°; HOCH₂CH₂, PhMe, 3.5, 80, 131°; PhCH₂, C₆H₆, 0.5, 90, 196°; Ph₂CH, PhMe, 3, 56, 263°; PhCH₂CH₂, PhMe, 2, 77, 260°; PhCH₂CHPh, C₆H₆, 9, 53, 245°; PhOCH₂CH₂, PhMe, 4.5, 75, 184°; BzCH₂, C₆H₆, 2, 96, 308°; 3,4-(MeO)₂C₆H₃COCH₂, C₆H₆-alc., 0.3, 64, 271°; p-O₂NC₆H₄CH₂, PhMe, 5.5, 66, 266°; 2,4-(O₂N)₂C₆H₃, PhMe, 1, 56, 294°. The following [4-H₂NC₅H₄N(CH₂)_nNC₅H₄-4]Br₂ were similarly obtained (n, solvent, reflux time, % yield, and m.p. of product given): 4, PhMe, 2, 87, 273°; 6, PhMe, 14, 91, 303°; 8, PhMe, 5.5, 84, 300°; 9, PhMe, 5, 14, 221°; 10, PhMe, 5, 88, 247°; 11, PhMe, 7.5, 48, 216°; 12, PhMe, 13, 29, 209°; 16, PhMe (prepared from alkyl iodide), 11, 94, 185°. The following [2,4-Me(H₂N)C₅H₄N(CH₂)_nNC₅H₄(NH₂)Me- 4,2]Br₂ were obtained (n, solvent, reflux time in hrs., % yield, and m.p. given): 8, PhMe, 8, 60, 304°; 9, PhMe, 9, 17, 275°. IIa (30 g.) in 700 mL. MeOH treated in 1 h. with 250 g. NaBH₄, the mixture heated on a steam bath, cooled, treated with 500 mL. H₂O, covered with 2 l. Et₂O, the 2 phases treated with anhydrous K₂CO₃ to convert the lower layer to a paste, the Et₂O separated, evaporated, the 20 g. oil dissolved in 30 mL. alc., and treated with dry HCl gave 12.2 g. 1-(3,4-dimethoxybenzyl)-4-aminopiperidine-2HCl, m. 223-5° (decomposition) (MeOH-Et₂O). Other 4-aminopiperidines were obtained from the resp. quaternary salts by the same procedure. The free bases were hygroscopic oils. The amines had to be salted out with NaCl. When 4-aminopiperidines, as free bases, were required for further work, they were used directly in the crude state. 1-Methyl-4-aminopiperidine and 1-(β-hydroxyethyl)-4-aminopiperidine, both formed hygroscopic salts with HCl. The following 4-(N-substituted-amino)piperidine-2HCl were thus obtained (R, % yield, and m.p. given): EtO₂CCH₂, 17, 169°; PhCH₂, 41, 255°; PhCH₂CH₂, 88, 321°; PhCH₂CHPh, 40, 237° (decomposition); PhOCH₂CH₂, 44, 220°; PhCH(OH)CH₂, 90, 248° (decomposition); 3,4-(MeO)₂C₆H₃CH(OH)CH₂, 56, 220° (decomposition); p-O₂NC₆H₄CH₂, 10, 265° (decomposition). The following 4-H₂NC₅H₄N(CH₂)_nNC₅H₄NH₂-4.4HCl were similarly obtained (n, % yield, and m.p. given): 6, 22, 204°; 10, 16, 295°; 12, 34, 311°; 16, 20, 315°. 1,10-Bis(4-amino-1-piperidyl)decane was also characterized by preparation of the bis(dichloroacetate)-2HCl, m. 227-30° (decomposition) (alc.). 1-Methyl-4-aminopiperazine (8.1 g.) and 11.2 g. veratraldehyde in 200 mL. PhMe refluxed 1.5 h., evaporated, the residue dissolved in 150 mL. MeOH, the solution reduced with 40 g. NaBH₄, heated 0.5 h. on the steam bath, and the 20.5 g. yellow oil treated with alc. HCl gave 10 g. 1-methyl-4-(3,4-dimethoxybenzylamine)piperazine, m. 199-202° (decomposition). Other secondary aminopiperidines and aminopiperazines were given in a table. Attempts to reduce imines derived from 1-phenyl-2-propanone and 1-substituted 4-aminopiperidines with NaBH₄ did not lead to desired products, probably because of cleavage of the unstable imines. 3-Aminopyridine (16.8 g.) and 30 g. veratraldehyde in 500 mL. xylene refluxed 24 h. and the 45.5 g. residual oily imine in MeOH reduced with NaBH₄ gave 33 g. 3-(3,4-dimethoxybenzylamino)pyridino (V), m. 123-5° (MeOH). The other pyridines were similarly prepared The following RNHR’ were thus obtained (R, R’, % yield, and m.p. given): 3,4- dimethoxybenzyl, 1-methyl-4-piperidyl, 60, 254-6° (decomposition); 3,4,5-trimethoxybenzyl, 1-methyl-4-piperidyl, 37, 264-5° (decomposition); 3,4-dimethoxybenzyl, 1-(β-hydroxyethyl)-4-piperidyl, 12, 255-6° (decomposition); 4-methoxybenzyl, 1-(3,4-dimethoxybenzyl)-4-piperidyl, 46, 274-5° (decomposition); 3,4,5-trimethoxybenzyl, 1-methyl-4-piperazyl, 56, 135-7°; p-dimethylaminobenzyl, 1-methyl-4-piperazyl, 40, 125-7° (157-60°); 3-pyridylmethyl, 1-methyl-4-piperazyl, 95, 201-2° (220-6° with 0.5H₂O); 1-hydroxy-1-phenyl-2-Pr, 1-methyl-4-piperazyl, 25, 219-21° (decomposition); 3,4-dimethoxybenzyl, 2-pyridyl, 65, 102-3°; 3,4,5-trimethoxybenzyl, 2-pyridyl, 45, 167-8°; p-dimethylaminobenzyl, 2-pyridyl, 52, 125-6°; 3,4,5-trimethoxybenzyl, 3-pyridyl, 63, 109-10°; 3,4,5-trimethoxybenzyl, 3-pyridylmethyl, 90, 205-7°; p-dimethylaminobenzyl, 3-pyridylmethyl, 96, 185-6° (decomposition); 3,4-dimethoxybenzyl, 4-pyridylmethyl, 22, 200° (decomposition); 3,4,5-trimethoxyhenzyl, 4-pyridylmethyl, 43, 214-16°; p-dimethylaminobenzyl, 4-pyridylmethyl, 45, 195-6°; 1-phenyl-2-Pr, 3-pyridylmethyl, 55, 205-7°; 1-phenyl-2-Pr, 4-pyridylmethyl, 80, 181-3°; 3,4,5-trimethoxybenzyl, NMe₂, 45, 81-3; p-dimethylaminobenzyl, NMe₂, 7, 158-61° (decomposition); 1-phenyl-2-Pr, NMe₂, 70, 123-5°; 1,2-diphenylethyl, NMe₂, 23, 183-5°; PhCH:CHCHMe, NMe₂, 5, 117-20° (decomposition). V (14.1 g.) converted rapidly to the MeI salt, evaporated, the crystals suspended in 200 mL. MeOH, reduced with 125 g. NaBH₄, and the residual oil treated with HCl gave 14.6 g. 1-methyl-3-(3,4-dimethoxybenzylamino)piperidine-2HCl, m. 233-5° (decomposition). 3-Aminopiperidine (7.6 g.), 12.7 g. veratraldehyde, and 250 mL. PhMe refluxed 3.5 h., the crude imine reduced with NaBH₄ in alc., and crystallized gave 20.6 g. V.2HCl, m. 229-31° (alc.). Reduction of p-dimethylaminobenzylidene derivative and isolation gave 76% 3-(4-dimethylaminobenzylamino)piperidine, no definite m.p. 3-(3-Pyridylmethylamino)piperidine was obtained in 79% yield by reduction of the 3-pyridylidene derivative and isolated as the tri-HCl salt. Veratraldehyde (16.3 g.) and 6.5 g. N,N-dimethylhydrazine mixed, the oil taken up in 200 mL. C₆H₆, the solution refluxed 4 h., evaporated, and the hydrazone reduced in MeOH with NaBH₄ gave 13.9 g. N,N-dimethyl-N-(3,4-dimethoxybenzyl)hydrazine-HCl, m. 172-4.5°. The other hydrazine derivatives above were prepared by the same method.

Journal of Organic 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 C12H9NO, Safety of 4-Amino-2-picoline.

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

Matthews, Thomas P. published the artcileDesign and evaluation of 3,6-di(hetero)aryl imidazo[1,2-a]pyrazines as inhibitors of checkpoint and other kinases, HPLC of Formula: 197958-29-5, the publication is Bioorganic & Medicinal Chemistry Letters (2010), 20(14), 4045-4049, database is CAplus and MEDLINE.

A range of 3,6-di(hetero)aryl imidazo[1,2-a]pyrazine ATP-competitive inhibitors, e.g. I and II, of CHK1 were developed by scaffold hopping from a weakly active screening hit. Efficient synthetic routes for parallel synthesis were developed to prepare analogs with improved potency and ligand efficiency against CHK1. Kinase profiling showed that the imidazo[1,2-a]pyrazines could inhibit other kinases, including CHK2 and ABL, with equivalent or better potency depending on the pendant substitution. These 3,6-di(hetero)aryl imidazo[1,2-a]pyrazines appear to represent a general kinase inhibitor scaffold.

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, HPLC of Formula: 197958-29-5.

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

Ladjarafi, Abdelkader published the artcileA DFT study of the tautomeric equilibria of substituted pyridone-like derivatives: Sulphur versus oxygen and imino effect, Formula: C6H8N2, the publication is Journal of Molecular Structure: THEOCHEM (2004), 709(1-3), 129-134, database is CAplus.

Several pyridone-like compounds, where the extracyclic oxygen atom has been replaced by a sulfur atom or an imino NH group, have been studied using B3LYP/6-311 + G** calculations We found that the NH substituted species differ from the other ones: a single tautomeric form, i.e. the aminopyridine one, strongly dominates either in the gas phase or in the presence of a polar solvent like DMSO. In the gas phase or in solution, pyridinethiol species are more favored than the pyridinol ones relatively to their corresponding tautomers. The zero point vibration energy and the entropic contribution to the free energy of the reaction play a more determining role for the sulfur containing species.

Journal of Molecular Structure: THEOCHEM 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, Formula: C6H8N2.

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

Yin, Xiaojun published the artcileStar-Shaped Macromolecules with the Core of Hexakis-(fluoren-2-yl)benzene and the Periphery of Pyridine: Synthesis and Application as Solution-Processable Electron-Transport Materials, COA of Formula: C5H6BNO2, the publication is Macromolecular Rapid Communications (2015), 36(18), 1658-1663, database is CAplus and MEDLINE.

Three new star-shaped macromols. with hexakis(fluoren-2-yl)benzene as the core and pyridine as the periphery (2Py-HFB, 3Py-HFB, and 4Py-HFB) are synthesized and characterized. The synthetic conditions of octacarbonyldicobat-catalyzed cycloaddition reaction for different alkyne precursors are investigated. The coordination interaction between the pyridine ring of alkyne precursor and the cobalt catalyst may result in very low yield of the cyclotrimerization product. However, with the increase of the catalyst loading, the yields of the intermediates of cyclopentadienone are enhanced. Then, the desired cyclotrimerization products can be obtained by the Diels-Alder reactions of cyclopentadienone with acetylene in good yield. These new compounds exhibit good thermal stability and favorable electron affinity. By using the new compounds as electron-transporting materials, all-solution-processed phosphorescent organic light-emitting devices (OLEDs) show good performance with a maximum current efficiency of 5.6 cd A^-1 and maximum external quantum efficiency of 4.68%.

Macromolecular Rapid Communications 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 C14H10N2O, COA of Formula: C5H6BNO2.

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

Matralis, Alexios N. published the artcileDevelopment of Chemical Entities Endowed with Potent Fast-Killing Properties against Plasmodium falciparum Malaria Parasites, Related Products of pyridine-derivatives, the publication is Journal of Medicinal Chemistry (2019), 62(20), 9217-9235, database is CAplus and MEDLINE.

One of the attractive properties of artemisinins is their extremely fast-killing capability, quickly relieving malaria symptoms. Nevertheless, the unique benefits of these medicines are now compromised by the prolonged parasite clearance times and the increasing frequency of treatment failures, attributed to the increased tolerance of Plasmodium falciparum to artemisinin. This emerging artemisinin resistance threatens to undermine the effectiveness of antimalarial combination therapies. Herein, we describe the medicinal chem. efforts focused on a cGMP-dependent protein kinase (PKG) inhibitor scaffold, leading to the identification of novel chem. entities with very potent, similar to artemisinins, fast-killing potency against asexual blood stages that cause disease, and activity against gametocyte activation that is required for transmission. Furthermore, we confirm that selective PKG inhibitors have a slow speed of kill, while chemoproteomic anal. suggests for the first time serine/arginine protein kinase 2 (SRPK2) targeting as a novel strategy for developing antimalarial compounds with extremely fast-killing properties.

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, Related Products of pyridine-derivatives.

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

Shkurko, O. P. published the artcileSubstituent effects on the amino-group chemical shifts in NMR spectra of substituted aminopyridines, Formula: C6H8N2, the publication is Khimiya Geterotsiklicheskikh Soedinenii (1990), 54-9, database is CAplus.

Correlation analyses are presented for amino-group proton chem. shifts in m– and p-substituted (with respect to the amino group) 2-, 3-, and 4-aminopyridines (6 series altogether) using inductive and resonant substituent constants

Khimiya Geterotsiklicheskikh Soedinenii 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 C7H5ClN2S, Formula: C6H8N2.

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

Brunner, Katharina published the artcileInhibitors of the Cysteine Synthase CysM with Antibacterial Potency against Dormant Mycobacterium tuberculosis, SDS of cas: 197958-29-5, the publication is Journal of Medicinal Chemistry (2016), 59(14), 6848-6859, database is CAplus and MEDLINE.

Cysteine is an important amino acid in the redox defense of Mycobacterium tuberculosis, primarily as a building block of mycothiol. Genetic studies have implicated de novo cysteine biosynthesis in pathogen survival in infected macrophages, in particular for persistent M. tuberculosis. Here, we report on the identification and characterization of potent inhibitors of CysM, a critical enzyme in cysteine biosynthesis during dormancy. A screening campaign of 17,312 compounds identified ligands that bind to the active site with micromolar affinity. These were characterized in terms of their inhibitory potencies and structure-activity relationships through hit expansion guided by three-dimensional structures of enzyme-inhibitor complexes. The top compound binds to CysM with 300 nM affinity and displays selectivity over the mycobacterial homologues CysK1 and CysK2. Notably, two inhibitors show significant potency in a nutrient-starvation model of dormancy of Mycobacterium tuberculosis, with little or no cytotoxicity toward mammalian cells.

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, SDS of cas: 197958-29-5.

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

Ojha, K. G. published the artcileSynthesis and antibacterial activity of some substituted phenothiazin-3-ones, Related Products of pyridine-derivatives, the publication is International Journal of Chemical Sciences (2003), 1(4), 347-350, database is CAplus.

1,2,4-Trihalophenothiazin-3-ones were prepared by condensing 2-aminobenzenethiols with chloranil/bromanil in 1:1 molar ratio. These compounds on refluxing with aryl amine and anhydrous NaOAc in EtOH gave substituted 2-arylaminophenothiazin-3-ones, which exhibited antibacterial activity.

International Journal of Chemical Sciences 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, Related Products of pyridine-derivatives.

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

Chen, Jiayan published the artcilePalladium(II)-catalyzed enantioselective arylation of α-imino esters, Category: pyridine-derivatives, the publication is Journal of Organic Chemistry (2012), 77(19), 8541-8548, database is CAplus and MEDLINE.

A protocol for Pd(II)-catalyzed asym. arylation of N-aryl imino esters has been developed. The method affords a practical and direct access to chiral arylglycine derivatives in good yields and with high enantioselectivities.

Journal of 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

Louw, Stefan published the artcileHigh-efficiency hydrophilic interaction chromatography by coupling 25 cm × 4.6 mm ID × 5 μm silica columns and operation at 80°C, Safety of 4-Amino-2-picoline, the publication is Journal of Chromatography A (2010), 1217(4), 514-521, database is CAplus and MEDLINE.

Recently, hydrophilic interaction chromatog. (HILIC) has emerged as a valuable orthogonal tool to reversed-phase liquid chromatog. (RP-LC) as it allows for resolution of highly polar ionisable compounds The relationships between separation efficiency, column length and speed of anal. for 4.6 mm ID × 5 μm silica particle columns in HILIC are demonstrated using kinetic plots. The kinetic plots constructed for conventional pressure systems operating at 350 bar and at 30° and 80° are confirmed using exptl. data for different column lengths. Efficiencies of more than 130,000 theor. plates could be achieved by connecting up to six columns of 25 cm. As expected, a significant gain in anal. speed without loss of efficiency could be obtained by operating at 80° compared to 30°. The advantages of using long columns in HILIC in combination with elevated column temperature for the pharmaceutical industry are illustrated using test mixtures comprised of com. available ionisable compounds (including some containing functional groups with potential genotoxic typical structural alerts) as well as real polar ionisable pharmaceuticals.

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 C6H8N2, Safety of 4-Amino-2-picoline.

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