Day: November 30, 2022

S’ari, Mark published the artcileLow dose scanning transmission electron microscopy of organic crystals by scanning moire fringes, Application of 3-Ethyl 5-methyl 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate, the main research area is STEM scanning moire fringes organic crystals; Bright field STEM; Dose-limited resolution; Low dose; Organic crystals; Scanning moiré fringes.

In the pharmaceutical industry, it is important to determine the effects of crystallization and processes, such as milling, on the generation of crystalline defects in formulated products. Conventional transmission electron microscopy and scanning transmission electron microscopy (STEM) can be used to obtain information on length scales unobtainable by other techniques, however, organic crystals are extremely susceptible to electron beam damage. This work demonstrates a bright field (BF) STEM method that can increase the information content per unit specimen damage by the use of scanning moire fringes (SMFs). SMF imaging essentially provides a magnification of the crystal lattice through the interference between closely aligned lattice fringes and a scanning lattice of similar spacing. The generation of SMFs is shown for three different organic crystals with varying electron beam sensitivity, theophylline, furosemide and felodipine. The electron fluence used to acquire the BF-STEM for the most sensitive material, felodipine was approx. 3.5 e-/Å2. After one addnl. scan of felodipine (total fluence of approx. 7.0 e-/Å2), the SMFs were no longer visible due to extensive damage caused to the crystal. Irregularity in the SMFs suggested the presence of defects in all the organic crystals. Further effort is required to improve the data anal. and interpretation of the resulting SMF images, allowing more information regarding the crystal structure and defects to be extracted

Micron published new progress about Crocidolite asbestos Role: ANT (Analyte), ANST (Analytical Study). 72509-76-3 belongs to class pyridine-derivatives, name is 3-Ethyl 5-methyl 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C18H19Cl2NO4, Application of 3-Ethyl 5-methyl 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Wang, Yaping published the artcileOne-Pot Double Benzylation of 2-Substituted Pyridines using Palladium-Catalyzed Decarboxylative Coupling of sp2 and sp3 Carbons, Application of 3-Methylpicolinic acid hydrochloride, the main research area is diarylmethane preparation; picolinic acid benzyl bromide decarboxylative double benzylation palladium silver.

An efficient and practical decarboxylative double benzylation method for various 2-picolinic acids has been established by using a bimetallic catalytic system of palladium(II) chloride (PdCl2) and silver(I) oxide (Ag2O), which offered a variety of diarylmethane derivatives e.g., I, with moderate to good yields.

Advanced Synthesis & Catalysis published new progress about Aralkyl bromides Role: RCT (Reactant), RACT (Reactant or Reagent). 123811-72-3 belongs to class pyridine-derivatives, name is 3-Methylpicolinic acid hydrochloride, and the molecular formula is C7H8ClNO2, Application of 3-Methylpicolinic acid hydrochloride.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Zhang, Huiping published the artcileSynthesis of 2-cyanoacrylates containing pyridinyl moiety under ultrasound irradiation, COA of Formula: C6H7ClN2, the main research area is pyridinylaminocyanoacrylate preparation antitumor; cyanoacrylate pyridinylamino preparation antitumor; methylthiocyanoacrylate pyridinamine substitution ultrasound.

Reaction of NCCH2CO2Et with CS2 and Me2SO4 in the presence of NaOMe in anhydrous MeOH yields 2-cyano-3,3-bis(methylthio)acrylate. Further nucleophilic substitution with 3-amino-2-chloro-4-methylpyridine under ultrasonic irradiation afforded 3-[(2-chloro-4-methylpyridin-3-yl)amino]-2-cyano-3-methylthioacrylate as key intermediate. The title compounds were then obtained through the reaction of the key intermediate with primary aliphatic amines under reflux. All new structures were verified by elemental anal., IR, 1H NMR and mass spectra. In the MTT test, the compounds were found to possess moderate antitumor activities against PC3 and A431 cells.

Journal of Heterocyclic Chemistry published new progress about Aliphatic amines Role: RCT (Reactant), RACT (Reactant or Reagent). 133627-45-9 belongs to class pyridine-derivatives, name is 2-Chloro-4-methylpyridin-3-amine, and the molecular formula is C6H7ClN2, COA of Formula: C6H7ClN2.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Swahn, Britt-Marie published the artcileDesign and Synthesis of β-Site Amyloid Precursor Protein Cleaving Enzyme (BACE1) Inhibitors with in Vivo Brain Reduction of β-Amyloid Peptides, SDS of cas: 917471-30-8, the main research area is aminoisoindole BACE1 inhibitor brain reduction beta amyloid peptide.

The evaluation of a series of aminoisoindoles as β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors and the discovery of a clin. candidate drug for Alzheimer’s disease, (S)-32 (I, AZD3839), are described. The improvement in permeability properties by the introduction of fluorine adjacent to the amidine moiety, resulting in in vivo brain reduction of Aβ40, is discussed. Due to the basic nature of these compounds, they displayed affinity for the human ether-a-go-go related gene (hERG) ion channel. Different ways to reduce hERG inhibition and increase hERG margins for this series are described, culminating in (S)-16 (II) and (R)-41 (III) showing large in vitro margins with BACE1 cell IC50 values of 8.6 and 0.16 nM, resp., and hERG IC50 values of 16 and 2.8 μM, resp. Several compounds were advanced into pharmacodynamic studies and demonstrated significant reduction of β-amyloid peptides in mouse brain following oral dosing.

Journal of Medicinal Chemistry published new progress about Absolute configuration (enantiomer preference for enzyme binding). 917471-30-8 belongs to class pyridine-derivatives, name is (5-(Prop-1-yn-1-yl)pyridin-3-yl)boronic acid, and the molecular formula is C8H8BNO2, SDS of cas: 917471-30-8.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Perez-Pineiro, Rolando published the artcileSynthesis of sulfur-containing aryl and heteroaryl vinyls via Suzuki-Miyaura cross-coupling for the preparation of SERS-active polymers, Product Details of C6H8BNO2S, the main research area is sulfur aryl heteroaryl viny Suzuki coupling.

The preparation of sulfur-containing aryl and heteroaryl vinyl co-monomers via Suzuki-Miyaura cross-coupling between the corresponding mercaptomethyl arylboronates and in situ-generated vinyl bromides is described. Surface-enhanced Raman scattering (SERS) studies of the target compounds on gold nanoparticles confirmed their potential as spectroscopic tags in the fabrication of SERS-encoded polymers for combinatorial screening and biomedical diagnostics.

Tetrahedron Letters published new progress about Aryl alkenes Role: SPN (Synthetic Preparation), PREP (Preparation). 321438-86-2 belongs to class pyridine-derivatives, name is 6-(Methylthio)pyridin-3-ylboronic acid, and the molecular formula is C6H8BNO2S, Product Details of C6H8BNO2S.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Ramil, Carlo P. published the artcileSequence-Specific 2-Cyanobenzothiazole Ligation, HPLC of Formula: 133627-45-9, the main research area is cyanobenzothiazole ligation protein labeling.

The use of small, natural chem. reporters in conjunction with catalyst-free bioorthogonal reactions will greatly streamline protein labeling in a cellular environment with min. perturbation to their function. Here we report the discovery of a 2-cyanobenzothiazole (CBT)-reactive peptide tag, CX10R7, from a cysteine-encoded peptide phage library using the phage-assisted interrogation of reactivity method. Fusion of CX10R7 with a protein of interest allows site-specific labeling of the protein with CBT both in vitro and on the surface of E. coli cells. Mutagenesis studies indicated that the reactivity and specificity of CX10R7 are attributed to the sequence environment, in which the residues surrounding cysteine help to stabilize the ligation product.

Journal of the American Chemical Society published new progress about Aromatic nitriles Role: RCT (Reactant), RACT (Reactant or Reagent). 133627-45-9 belongs to class pyridine-derivatives, name is 2-Chloro-4-methylpyridin-3-amine, and the molecular formula is C6H7ClN2, HPLC of Formula: 133627-45-9.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Miura, Hiroki published the artcileRuthenium-Catalyzed Intermolecular Hydroacylation of Internal Alkynes: The Use of Ceria-Supported Catalyst Facilitates the Catalyst Recycling, HPLC of Formula: 71255-09-9, the main research area is conjugated enone preparation; ceria supported ruthenium hydroacylation alkyne aldehyde.

Intermol. hydroacylation of internal alkynes by aromatic aldehydes, catalyzed by Ru/CeO2 or [RuCl2(p-cymene)]2 in the presence of sodium formate and Xantphos, gave conjugated enones. E.g., in presence of Ru/CeO2, hydroacylation of PhCCPh by PhCHO gave 52% enone I (64:36 E/Z). The solid Ru/CeO2 continued to show catalytic activity and gave enones without significant decreases in yields for at least three times.

Chemistry – A European Journal published new progress about Alkynes, internal Role: RCT (Reactant), RACT (Reactant or Reagent). 71255-09-9 belongs to class pyridine-derivatives, name is 2-Methoxynicotinaldehyde, and the molecular formula is C7H7NO2, HPLC of Formula: 71255-09-9.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Ma, Jiajia published the artcileFacile access to fused 2D/3D rings via intermolecular cascade dearomative [2+2] cycloaddition/rearrangement reactions of quinolines with alkenes, Formula: C7H6ClNO2, the main research area is quinoline alkene iridium photochem diastereoselective intermol dearomative cycloaddition rearrangement; azatetracyclododecatriene preparation; tetrahydro benzocyclobutapyridine preparation.

Two types of energy-transfer-mediated cascade dearomative [2+2] cycloaddition/rearrangement reactions of quinoline derivatives with alkenes, which provide a straightforward avenue to 2D/3D pyridine-fused 6-5-4-3- and 6-4-6-membered ring systems are reported. Notably, this energy-transfer-mediated strategy features excellent diastereoselectivity that bypasses the general reactivity and selectivity issues of photochem. [2+2] cycloaddition of various other aromatics Tuning the aza-arene substitutions enabled selective diversion of the iridium photocatalyzed energy transfer manifold towards either cyclopropanation or cyclobutane-rearrangement products. D. functional theory calculations revealed a cascade energy transfer scenario to be operative.

Nature Catalysis published new progress about [2+2] Cycloaddition reaction catalysts (stereoselective,photochem.). 24484-93-3 belongs to class pyridine-derivatives, name is Methyl 4-chloropicolinate, and the molecular formula is C7H6ClNO2, Formula: C7H6ClNO2.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Tanga, M. J. published the artcileSyntheses of five potential heterocyclic amine food mutagens, Safety of 3-Bromo-2,6-dimethylpyridin-4-amine, the main research area is aminoimidazopyridine trimethyl preparation; imidazopyridine amino trimethyl preparation; food mutagen potential preparation.

The syntheses of the potential heterocyclic amine food mutagens, 3,5,7-trimethyl-2-aminoimidazo[4,5-b]pyridine, 1,4,7-trimethyl-2-aminoimidazo[4,5-c]pyridine, 1,6,7-trimethyl-2-aminoimidazo[4,5-c]pyridine, 3,4,6-trimethyl-2-aminoimidazo[4,5-c]pyridine, and 1,4,6-trimethyl-7-aminoimidazo[4,5-c]pyridine are described.

Journal of Heterocyclic Chemistry published new progress about Mutagens, food Role: SPN (Synthetic Preparation), PREP (Preparation). 33259-24-4 belongs to class pyridine-derivatives, name is 3-Bromo-2,6-dimethylpyridin-4-amine, and the molecular formula is C7H9BrN2, Safety of 3-Bromo-2,6-dimethylpyridin-4-amine.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Rogers, David A. published the artcileAmplification of Trichloroisocyanuric Acid (TCCA) Reactivity for Chlorination of Arenes and Heteroarenes via Catalytic Organic Dye Activation, Recommanded Product: 2-Methoxynicotinaldehyde, the main research area is chlorination arene heteroarene trichloroisocyanuric acid brilliant green catalyst.

Heteroarenes and arenes that contain electron-withdrawing groups are chlorinated in good to excellent yields (scalable to gram scale) using trichloroisocyanuric acid (TCCA) and catalytic Brilliant Green (BG). Visible-light activation of BG serves to amplify the electrophilic nature of TCCA, providing a mild alternative approach to acid-promoted chlorination of deactivated (hetero)aromatic substrates. The utility of the TCCA/BG system is demonstrated through comparison to other chlorinating reagents and by the chlorination of pharmaceuticals including caffeine, lidocaine, and phenazone.

Organic Letters published new progress about Aryl chlorides Role: SPN (Synthetic Preparation), PREP (Preparation). 71255-09-9 belongs to class pyridine-derivatives, name is 2-Methoxynicotinaldehyde, and the molecular formula is C7H7NO2, Recommanded Product: 2-Methoxynicotinaldehyde.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem