Category: 73018-09-4

Alhatem, Aamer A. published the artcile< Tautomeric equilibria of substituted 2-pyridone/2-hydroxypyridine in the gas and aqueous phases>, Safety of 6-Chloropyridin-2-ol, the main research area is pyridone hydroxypyridine tautomer substituent effects formation enthalpy free energy.

Heats of formation, entropies and Gibbs free energies for the twenty structures of substituted 2-pyridone and 2-hydroxypyridine were studied using semiempirical Austin Model (AM1) and Parametric Method 3 (PM3) calculations at the SCF level, both in the gas and liquid phases, with full geometry optimization. It was revealed from the study that 2-hydroxypyridine is predominant in gas phase, while 2-pyridone in the liquid phase which agrees with the exptl. and theor. predictions. All substituents such as F, Cl, OH, CH3, NH2, NO2, CHO, CN, CF3 stabilize the 2-pyridone in the gas and liquid phases except F, Cl and NH2 in PM3 calculations in the gas phase. The substituents stabilization is more effective in liquid phase. This was also confirmed by thermodn. calculations and isodesmic reactions.

Chemical Science International Journal published new progress about Entropy. 73018-09-4 belongs to class pyridine-derivatives, and the molecular formula is C5H4ClNO, Safety of 6-Chloropyridin-2-ol.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Echterhoff, Antje K. C.; Yogendra, Sivathmeehan; Koesters, Jutta; Fischer, Roland; Weigand, Jan J. published the artcile< A versatile protocol for the synthesis of pyrazolyl-substituted pyridinium and guanidinium salts from pyridone and urea derivatives>, HPLC of Formula: 73018-09-4, the main research area is pyridinium pyrazolyl guanidinium triflate preparation crystal structure; tripyridyl phosphite preparation crystal structure.

The trication I was used as a convenient pyrazolyl-transfer reactant to convert 2-pyridone, 4-pyridone and urea derivatives such as benzimidazol-2-one and theobromine to their pyrazolyl substituted triflate salts, e.g., II. The conversion represented a new, efficient and highly functional group-compatible approach that yielded the desired products conveniently and in high yields. Typically the reaction proceeded via exchange of carbonyl oxygen atom of the substrate for pyrazolyl moiety. However, for the structurally related 3-hydroxypyridines, a different reaction pathway occurred giving tripyridyl phosphites, e.g., III which was explained by the lactam-lactim tautomerism of the substrate. The structural arrangements of most of the products were confirmed by X-ray crystallog. anal.

European Journal of Organic Chemistry published new progress about Crystal structure. 73018-09-4 belongs to class pyridine-derivatives, and the molecular formula is C5H4ClNO, HPLC of Formula: 73018-09-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Graca, Catia A. L.; Mendes, Maria Anita; Teixeira, Antonio Carlos S. C.; Velosa, Adriana Correia de published the artcile< Anoxic degradation of chlorpyrifos by zerovalent monometallic and bimetallic particles in solution>, Safety of 6-Chloropyridin-2-ol, the main research area is chlorpyrifoszerovalent monometallic bimetallic particle anoxic degradation; Bimetallic particles; Chlorpyrifos; Reductive degradation; Zerovalent copper; Zerovalent metals.

The degradation of highly toxic and persistent chlorinated organic compounds by zerovalent metals (ZVMs) has received considerable attention for in situ groundwater remediation. Due to its abundance and low toxicity, iron has been mostly applied for such purposes, despite several limitations, such as rapid surface passivation and little efficacy towards certain contaminants. Given that, we evaluated monometallic zerovalent iron (ZVI), copper (ZVC) and zinc (ZVZ), and bimetallic copper-coated ZVI (ZVI/Cu) and ZVZ (ZVZ/Cu) for anoxic reductive degradation of chlorpyrifos (CP). Two approaches to enhance metal reactivity were investigated: the synthesis of bimetallic particles with copper and the comparison between micro and nanoparticles. All of the tested monometallic and bimetallic particles dechlorinated the target mol., although complete chlorine removal was not achieved by any metal during the 30-d treatment period. Coating the zerovalent monometallic particles with copper enhanced reactivity. Reactivity was ZVC > ZVZ > ZVI for monometallic particles and ZVZ/Cu > ZVI/Cu for bimetallic microparticles. The anal. of the degradation products indicated the presence of dechlorinated compounds as well as 3,5,6-trichloro-2-pyridinol, a hydrolysis product.

Chemosphere published new progress about Decomposition (anoxic). 73018-09-4 belongs to class pyridine-derivatives, and the molecular formula is C5H4ClNO, Safety of 6-Chloropyridin-2-ol.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

den Hertog, H. J.; de Bruyn, J. published the artcile< Derivatives of pyridine and quinoline. LXXXVIII. Reactions of bromo derivatives of 2- and 3-ethoxypyridines when heated with hydrochloric acid>, Safety of 6-Chloropyridin-2-ol, the main research area is .

Following abstract When a bromoethoxypyridine (0.01 mole in 30-40 ml. 25% aqueous HCl) in a sealed tube is heated 4 hrs. at 160° in a shaking furnace, the Br is replaced by Cl when the former is in the 2- or 6-position, and the EtO group is replaced by the OH group. Thus 6-bromo-2-ethoxypyridine (I) gives 6-chloro-2-hydroxypyridine (II), m. 128.5-9°, and 2-bromo-3-ethoxypyridine (III) gives 2-chloro-3-hydroxypyridine, m. 169-70°, plus the corresponding dihydroxypyridines. The 3,5-di-Cl derivative of I yields 3,5,6-trichloro-2-hydroxypyridine, m. 174-5°. When the Br is in the 3- or 5-position it is not substituted by the procedure given. Thus 5-bromo-3-ethoxypyridine yields 5-bromo-3-hydroxypyridine. But either 3- or 5-bromo-2-ethoxypyridine yields mixtures of 3,5-dibromo-2-hydroxypyridine and 2-hydroxypyridine. As a further example of the positional reactivity of the Br, 2,5,6-tri-bromo-3-ethoxypyridine, m. 86-7°, prepared by heating 3-bromo-5-ethoxypyridine with Br in a sealed tube at 100°, gave 5-bromo-2,6-dichloro-3-ethoxypyridine, m. 77-8° with aqueous HCl. The EtO group in this case remained intact.

Recueil des Travaux Chimiques des Pays-Bas et de la Belgique published new progress about Chlorination. 73018-09-4 belongs to class pyridine-derivatives, and the molecular formula is C5H4ClNO, Safety of 6-Chloropyridin-2-ol.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Kuzuya, Masayuki; Noguchi, Akihiro; Mano, Eiichi; Okuda, Takachiyo published the artcile< The structure-reactivity-chemoselectivity relationship on the reactions of 1-unsubstituted tautomeric 2-pyridones with benzyne>, Product Details of C5H4ClNO, the main research area is tautomerism pyridone reaction benzyne.

The effect of tautomerism of 2-pyridones on the products obtained in reaction with benzyne was studied. Both Diels-Alder and Michael-type adducts were formed. The Diels-Alder reactivities were correlated with HOMO energy levels of the 2-pyridone form; the yields of the Michael-type adducts were associated with the tautomeric equilibrium Substituent effects on the tautomerism were discussed.

Bulletin of the Chemical Society of Japan published new progress about CNDO/2 (molecular orbital method). 73018-09-4 belongs to class pyridine-derivatives, and the molecular formula is C5H4ClNO, Product Details of C5H4ClNO.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Parchment, Oswald G.; Hillier, Ian H.; Green, Darren V. S. published the artcile< A theoretical study of the protometric equilibrium of 6-chloro-2-hydroxypyridine in the gas phase and in solution>, Application In Synthesis of 73018-09-4, the main research area is tautomerism chlorohydroxypyridine; quantum MP4 chlorohydroxypyridine tautomerism; solvation free energy chlorohydroxypyridine tautomerism; CISD quantum chlorohydroxypyridine tautomerism; correlation energy chlorohydroxypyridine tautomerism.

The equilibrium between 6-chloro-2-hydroxypyridine and 6-chloro-2-pyridone has been studied theor. in the gas phase, in water and and in carbon tetrachloride using a combination of electronic structure calculations, including geometry optimization and electron correlation, and mol. dynamics simulations. The use of a 6-31 G** basis with correlation, correctly predicts the increased stability of the enol form upon chlorine substitution at the 6 position and, at the MP4 level, yields agreement with the gas phase energetics to within 1.5 kcal mol-1. The accuracy of the computer simulations in predicting the differential free energy of solvation of the two tautomers in water is also ca. 1.5 kcal mol-1, while for solvation in carbon tetrachloride the corresponding accuracy is ca. 0.2 kcal mol-1.

Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) published new progress about CISD. 73018-09-4 belongs to class pyridine-derivatives, and the molecular formula is C5H4ClNO, Application In Synthesis of 73018-09-4.

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem