The Kissinger law and isokinetic effect: Part II. Experimental analysis

On the basis of copper sulphate pentahydrate thermal dissociation, for analyzed reactions I to IV, 6 thermokinetic equations was discussed. Arrhenius law parameters were determined and the isokinetic effect (IE) and Kissinger law appearing was analyzed. It was found that only dependence resulting from isokinetic effect, in the form k _m=q/T _m, relates to the suitable thermokinetic Eq. (2) and Kissinger law in modified form (14). The confirmation was made that the possibility of determining the averaged activation energy from thermokinetic equations using suitable correction coefficients exists.This revised version was published online in November 2005 with corrections to the Cover Date.     

A Convenient Method for the Preparation of Linear Furoquinolin-2-ones

Fries rearrangement of 7-acetoxy-4-methylquinolin-2-one and subsequent condensation of the 6-acetyl-7-hydroxy-4-methylquinolin-2-one obtained with -chloro ketones gives a series of furo[3,2-g]quinolin-7-ones.     

Reaction of hexafluoropropylene and its oligomers with acetone oxime

Reactions of perfluoropropylene and its oligomers with acetone oxime in the presence of a base afford perfluoroalkyl and/or perfluoroalkenyl ethers of acetone oxime. When heated to 100 °C, the 3-perfluoro-2-methyl-2-pentenyl ether of acetone oxime (3) is quantitatively converted to 4-hydroxy-3-methyl-5,5-bistrifluoromethyl-4-pentafluoroethyl-1-pyrroline (4), the structure of which was established by X-ray diffraction analysis. A convenient one-stage synthesis of perfluoro-3-isopropyl-4-methyl-3-penten-2-one (7) was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1068–1072, June, 1994.     

K对Mn—Co—O的结构及氧化活性的影响

利用XRD,TPD,TFD-MS及催化氧化反应等实验技术,研究了K对Mn-Co-O的结构及氧化活性的影响。XRD结果表明,Mn-Co-O系已形成反尖晶石型的MnCo_2O_4结构;K-Mn-Co-O系中除MnCo_2O_4型结构外,还有新相KMnO_2存在。根据O_2的TPD-MS及吡啶的TPD结果,Mn-Co-O中添加适量的K能提高供氧活性和增加供氧数目,但酸中心数目减少,强度降低。K对Mn-Co—O催化剂氧化活性的影响随反应物分子结构的不同而异,对乙酸乙脂、苯甲酰氯等极性有机物的完全氧化反应,K能提高氧化活性,但对苯、正己烷等非极性有机物的完全氧化反应,K使其活性降低。     

Alkylation of cobalt and lutetium tetra(3,5-di-tert-butyl-4-hydroxyphenyl)dodecachlorophthalocyanine complexes initiated with current

Electrochemical properties of tetra(3,5-di-tert-butyl-4-hydroxyphenyl)dodecachlorophthalocyanine complexes of cobalt(II) and lutetium(III) in DMF solutions have been studied. It was suggested that in the presence ofn-butyl bromide, the electrochemically generated monoanionic complexes undergo alkylation at the metal atom. The geometries of the neutral and anionic complexes were calculated by the ZINDO/I semiempirical method. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 289–293, February, 1998.     

Reaction ofo-aminobenzohydroxamic acid with aldehydes

The reaction of o-aminobenzohydroxamic acid with aliphatic, aromatic, or heterocyclic aldehydes leads to the formation of derivatives of 3-hydroxy-1,2-dihydroquinazolin-4-one. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 115–117, January, 1997.     

Asymmetric Reductive Alkylation of Alanylproline by the Ethyl Esters of 4-Substituted 2-Oxobutenoic Acids

A method was developed for the synthesis of N-[1-(S)-(ethoxycarbonyl)-3-phenylpropyl]alanylproline (enalapril) by reductive alkylation of alanylproline with ethyl 2-oxo-4-phenylbutenoate under the conditions of hydrogenation in the presence of palladium black and 1.6% Pd/C. The yield of enalapril amounted to 65%. With the ethyl ester of the -oxo acid the diastereoselectivity of formation of the S,S,S-diastereomer was higher than with the saturated synthon. It is assumed that with ethyl 2-oxo-4-phenylbutenoate as synthon a conformationally restricted surface complex is formed between the unsaturated synthon and the active centers of the catalyst. During reductive alkylation of alanylproline by ethyl 2-oxo-4-(2-thienyl)butenoate poisoning of the catalyst occurs.     

The effective use of substituted benzoic anhydrides for the synthesis of carboxamides

Various carboxamides are synthesized from the corresponding carboxylic acids and amines with high product-selectivities using 2-methyl-6-nitrobenzoic or 2,4,6-trichlorobenzoic anhydride in the presence of 4-(dimethylamino)pyridine.     

The effectiveness of solvents as hydrogen bond donors

Taft and Kamlet's -scale of solvent hydrogen bond donation ability is reexamined with regard to its correlations with three widely used polarity scales: Dimroth and Reichardt's E _T (30), Kosower's Z and Mayer's A _N , as well as with the _m values of the solvents when present as monomeric solutes. The correlation with E _T serves to extend the solvent -scale according to the expression:

Reactions of isoquinoline derivatives with pyridinium salts yielding 4-naphthylpyridines

Regiospecific introduction of the 2-naphthyl residue into position 4 of the pyridine ring occurs in the reactions of isoquinolinium salts with 4-methylpyridinium salts through the intermolecular transformation of the isoquinoline bicyclic system involving the methyl group of the pyridinium salt. The reaction occurs under the action of methylammonium sulfite in an aqueous medium on heating. This method provides ring transformation not only for isoquinolinium salts but even for unsubstituted isoquinoline.