Day: December 21, 2022

Young, Ian S. published the artcilePalladium-Catalyzed Site-Selective Amidation of Dichloroazines, Synthetic Route of 132097-09-7, the main research area is dichloroazine amide amidation palladium; chloroazinyl amide regioselective preparation; palladium amidation catalyst.

A highly site-selective amidation reaction of substituted 2,4-dichloroazines is reported. Palladium acetate/1,1′-bis(diphenylphosphino)ferrocene (dppf) was identified as the optimal catalyst system, producing >99:1 C-2/C-4 selectivity for most examples. The generality of this transformation was demonstrated through a survey of a diverse amide/substituted 2,4-dichloroazine scope, leading to the preparation of the desired C-2 amidated products in good to excellent yields.

Organic Letters published new progress about Amidation. 132097-09-7 belongs to class pyridine-derivatives, name is 2,4-Dichloro-3-methylpyridine, and the molecular formula is C6H5Cl2N, Synthetic Route of 132097-09-7.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Maiden, Tracy M. M. published the artcileSynthesis of Functionalized Pyridines via a Regioselective Oxazoline Promoted C-H Amidation Reaction, Recommanded Product: Ethyl 6-chloropicolinate, the main research area is oxazolylpyridine functionalized preparation rhodium silver catalyzed amidation; azaquinazoline scaffold preparation; pyridopyrimidinone preparation; nicotinamide derivative preparation heterocyclization; picolinamide derivative preparation heterocyclization.

The 1st Rh-catalyzed C-H amidation of pyridines is reported. The incorporation of a substituent at the C2 position both is crucial to the success of this transformation and provides considerable scope for further elaboration of the resulting products. Among these compounds, 2-chloropyridines allow access to a selection of intermediates including a versatile azaquinazoline scaffold.

Organic Letters published new progress about Amidation. 21190-89-6 belongs to class pyridine-derivatives, name is Ethyl 6-chloropicolinate, and the molecular formula is C8H8ClNO2, Recommanded Product: Ethyl 6-chloropicolinate.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Yastrebova, Ekaterina S. published the artcileProposed Dynamics of CDB3 Activation in Human Erythrocytes by Nifedipine Studied with Scanning Flow Cytometry, Formula: C17H18N2O6, the main research area is nifedipine erythrocyte CDB3 flow cytometry; adalat; band 3; calcium ions; kinetic modeling; red blood cells.

Nifedipine is calcium channels and pumps blocker widely used in medicine. However, mechanisms of nifedipine action in blood are not clear. In particular, the influence of nifedipine on erythrocytes is far from completely understood. In this work, applying scanning flow cytometry, we observed exptl. for the first time the dynamics behind a significant increase of HCO3-/Cl- transmembrane exchange rate of CDB3 (main anion exchanger, AE1, Band 3, SLC4A1) of human erythrocytes in the presence of nifedipine in blood. It was found that the rate of CDB3 activation is not limited by the rate of nifedipine binding and/or Ca2+ transport. In order to explain the exptl. data, we suggested a kinetic model assuming that the rate of CDB3 activation is limited by the dynamics of the balance between two intracellular processes (1) the activation of CDB3 limited by its interaction with intracellular Ca2+, and (2) the spontaneous deactivation of CDB3.

Cytometry, Part A published new progress about Algorithm. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Formula: C17H18N2O6.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Yu, Yong-Jie published the artcileAutomatic data analysis workflow for ultra-high performance liquid chromatography-high resolution mass spectrometry-based metabolomics, COA of Formula: C18H19Cl2NO4, the main research area is automatic data analysis algorithm UHPLC HRMS metabolomics; Automatic data analysis; Chemometrics; MATLAB GUI; UPLC-HRMS; Untargeted metabolomics.

Data anal. for ultra-performance liquid chromatog. high-resolution mass spectrometry-based metabolomics is a challenging task. The present work provides an automatic data anal. workflow (AntDAS2) by developing three novel algorithms, as follows: (i) a d.-based ion clustering algorithm is designed for extracted-ion chromatogram extraction from high-resolution mass spectrometry; (ii) a new maximal value-based peak detection method is proposed with the aid of automatic baseline correction and instrumental noise estimation; and (iii) the strategy that clusters high-resolution m/z peaks to simultaneously align multiple components by a modified dynamic programing is designed to efficiently correct time-shift problem across samples. Standard compounds and complex datasets are used to study the performance of AntDAS2. AntDAS2 is better than several state-of-the-art methods, namely, XCMS Online, Mzmine2, and MS-DIAL, to identify underlying components and improve pattern recognition capability. Meanwhile, AntDAS2 is more efficient than XCMS Online and Mzmine2. A MATLAB GUI of AntDAS2 is designed for convenient anal. and is available at the following webpage: http://software.tobaccodb.org/software/antdas2.

Journal of Chromatography A published new progress about Algorithm. 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, COA of Formula: C18H19Cl2NO4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Wang, Feifei published the artcileAssociation between potentially inappropriate medication and adverse drug reactions in hospitalized elderly patients, HPLC of Formula: 72509-76-3, the main research area is potentially inappropriate medication adverse drug reaction hospitalized human; adverse drug reactions; hospitalized; inappropriate medicine.

The Beers, European Union (EU) and Screening Tool of Older Persons’ potentially inappropriate Prescription (STOPP) criteria were developed to improve the safe use of medicines in the elderly. However, the predictive validity of existing criteria to detect adverse drug reactions (ADRs) remains unexplored. The objective of the current study was to determine whether the 2019 Beers, 2015 STOPP or 2015 EU potentially inappropriate medicine (PIM) criteria were associated with ADRs. A retrospective, cross-sectional investigation was conducted among older persons (â‰?0 years of age) admitted to a tertiary hospital in China between Apr. 2019 and Dec. 2019. PIMs were identified as per the Beers, EU and STOPP criteria definitions. ADRs were retrospectively evaluated by two clin. pharmacists using the Naranjo algorithm. Multivariate logistic regression was used to evaluate the factors associated with ADRs in the hospitalized patients. The study participants included 560 hospitalized patients (mean age 72.05 8.15). The prevalence of patients receiving at least one PIM was 52.1%, 37.0% and 42.9% according to the Beers, EU and STOPP criteria, resp. Univariate anal. showed that ADRs were associated with PIMs listed in the Beers criteria (OR: 2.093, 95% CI: 1.028-4.263, 0.042), but not with the STOPP-listed (OR: 0.536, 95% CI: 0.255-1.123, 0.098) and EU-listed PIMs (OR: 0.258, 95% CI: 0.118-0.563, 0.001). In contrast to the STOPP and EU criteria on PIMs, the Beers criteria were significantly associated with avoidable ADRs in hospitalized older persons.

Journal of Clinical Pharmacy and Therapeutics published new progress about Algorithm. 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, HPLC of Formula: 72509-76-3.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Utsey, Kiersten published the artcileQuantification of the impact of partition coefficient prediction methods on physiologically based pharmacokinetic model output using a standardized tissue composition, Computed Properties of 21829-25-4, the main research area is partition coefficient prediction physiol pharmacokinetic model standardized tissue composition.

Tissue:plasma partition coefficients are key parameters in physiol. based pharmacokinetic (PBPK) models, yet the coefficients are challenging to measure in vivo. Several mechanistic-based equations have been developed to predict partition coefficients using tissue composition information and the compound’s physicochem. properties, but it is not clear which, if any, of the methods is most appropriate under given circumstances. Complicating the evaluation, each prediction method was developed, and is typically employed, using a different set of tissue composition information, thereby making a controlled comparison impossible. This study proposed a standardized tissue composition for humans that can be used as a common input for each of the five frequently used prediction methods. These methods were implemented in R and were used to predict partition coefficients for 11 drugs, classified as strong bases, weak bases, acids, neutrals, and zwitterions. PBPK models developed in R (mrgsolve) for each drug and each set of partition coefficient predictions were compared with resp. observed plasma concentration data. Percent root mean square error and half-life percent error were used to evaluate the accuracy of the PBPK model predictions using each partition coefficient method as summarized by strong bases, weak bases, acids, neutrals, and zwitterions characterization. The anal. indicated that no partition coefficient method consistently yielded the most accurate PBPK model predictions. As such, PBPK model predictions using all partition coefficient methods should be considered during drug development.

Drug Metabolism & Disposition published new progress about Adipocyte. 21829-25-4 belongs to class pyridine-derivatives, name is Dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate, and the molecular formula is C17H18N2O6, Computed Properties of 21829-25-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Kovacs, Kornel L. published the artcileHydrogen evolution from dithionite and hydrogen photoproduction by hydrogenase incorporated into various hydrophobic matrixes, Formula: C26H42Br2N2, the main research area is hydrogen photoproduction hydrogenase dithionite viologen; ruthenium bipyridyl hydrogenase hydrogen photoproduction; surfactant liposome hydrogenase hydrogen photoproduction; solar energy hydrogen photoproduction water.

The effects of surfactants, lipids, and amphiphilic viologen mediators on H production from Na2S2O4 and tris(2,2′-bipyridine)Ru(2+) [15158-62-0] sensitized H photoproduction by hydrogenae from Thiocapsa roseopersicina were studied. Three systems which differed as to the nature of the hydrophobic matrix around the hydrogenase were tested. An enhanced hydrogenase activity was observed in the presence of surfactants in the 1-6 mM concentration range. Hydrogenase showed a selectivity for the amphiphilic viologens. N,N’-Diheptyl-4,4′-dipyridinium dichloride  [54451-15-9] was the most efficient electron mediator in both reactions. H photoproduction was not feasible in the detergent-hydrogenase system because of intensive foaming. Hydrogenase incorporated into liposomes catalyzed H photoevolution efficiently but the rate was decreasing in time, though reversibly. Using intact bacterial cells instead of purified hydrogenase yielded stable H photoevolution for â‰?2 h. This system offers several advantages for potential practical applications.

Biochimie published new progress about Photolysis. 36437-30-6 belongs to class pyridine-derivatives, name is 1,1-Di-n-octyl-4,4-bipyridinium Dibromide, and the molecular formula is C26H42Br2N2, Formula: C26H42Br2N2.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Puszko, A. published the artcile13C NMR spectra of 2,4-dihalopicolines and their N-oxides and IR spectra of 2-halopicoline N-oxides, 2,4-dihalopicoline N-oxides and 2-halo-4-nitropicoline N-oxides, Safety of 2,4-Dichloro-3-methylpyridine, the main research area is NMR IR spectra halopicoline; picoline halo NMR IR spectra; substituent effect NMR IR spectra halopicoline.

The 13C NMR and IR spectra of the title compounds were recorded and their spectral parameters assigned. The influence of electronic properties of the substituents on the direction of chem. shifts and νN-O values is discussed. The ratio between a substituted heterocyclic compound and its parent and the identically substituted benzene derivatives has been determined

Polish Journal of Chemistry published new progress about IR spectra. 132097-09-7 belongs to class pyridine-derivatives, name is 2,4-Dichloro-3-methylpyridine, and the molecular formula is C6H5Cl2N, Safety of 2,4-Dichloro-3-methylpyridine.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Barlin, G. B. published the artcileIonization constants of heterocyclic substances. IX. Protonation of aminopyridines and aminopyrimidinones, Product Details of C6H9N3O, the main research area is pyridines aminohydroxy ionization UV; basicity pyridines aminohydroxy; aminohydroxypyridine ionization UV; pyrimidines aminohydroxy ionization UV; protonation aminohydroxypyridine.

Ionization constants and uv spectra are reported for amino-2-hydroxypyridines (amino-2-pyridones), amino-4-hydroxypyridines(amino-4-pyridones), and amino-2,4-di-hydroxypryimidines (amino-2,4-pyrimidinediones) and their O-and ring N-Me derivatives Protonation of 3- and 5-amino-2-hydroxypyridines and 3,4-diamino-2-hydroxypyridine (I) occurs first at the amino group (the 3-NH2 of I), but 4- and 6-amino-2-hydroxypyridines and 2- and 3-amino-4-hydroxypyridines are protonated first at O. The most basic center of 4,5-diamino-2,6-dihydroxypyrimidine is the 5-NH2 group.

Journal of the Chemical Society [Section] B: Physical Organic published new progress about Ionization. 33631-04-8 belongs to class pyridine-derivatives, name is 2-Methoxypyridine-3,4-diamine, and the molecular formula is C6H9N3O, Product Details of C6H9N3O.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Barraclough, Paul published the artcileInotropic ‘A’ ring substituted sulmazole and isomazole analogs, Synthetic Route of 33631-04-8, the main research area is inotropic sulmazole isomazole analog; imidazopyridine preparation inotropic.

A series of “”A”” ring substituted sulmazole I [R = 4-, 5-, 6-MeO, 5-NO2, 5-Cl, 5-Me, 5-Ac; X = S, S(O), O] and isomazole analogs II [R = 2-, 5-, 6-MeO, 5-NH2, 5-NO2; X = S, S(O), O] were prepared and evaluated as inotropic agents. Thus, 5-methoxy-2,3-pyridinediamine was cyclized with 2-methoxy-4-(methylthio)benzoic acid to give I (R = 5-MeO, X = S), which was oxidized to give I [R = 5-MeO, X = S(O)]. PKA’s, protonation sites, and log P values were measured for selected compounds and their electronic properties were calculated No simple correlation between inotropic activity and pKA, protonation site, or log P value was observed However, in vitro inotropism did correlate with the calculated charge d. of the “”B”” ring imidazo nitrogen atom. The 6-position of sulmazole appeared to be the most tolerant toward substituents, the 6-amino derivative I [R = 6-NH, X = S(O)] being a more potent inotrope than sulmazole itself. 4-Methoxyisomazole had comparable in vivo inotropic properties to those of isomazole.

Journal of Medicinal Chemistry published new progress about Inotropics. 33631-04-8 belongs to class pyridine-derivatives, name is 2-Methoxypyridine-3,4-diamine, and the molecular formula is C6H9N3O, Synthetic Route of 33631-04-8.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem