On crossing of a level by processes defined by sums of a random number of terms

We study the joint distribution of boundary functionals related to the crossing of a positive (negative) level by a process consisting of a homogeneous Poisson process and a process defined by sums of a random number of continuously distributed terms.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 47, No. 7, pp. 897–914, July, 1995.     

Carbon-chain isomerization during the electrochemical fluorination in anhydrous hydrogen fluoride—a mechanistic study

The compounds i-C₄H₉SO₂F, i-C₃H₇SO₂F and cyclo-C₃H₇C(O)F have been subjected to electrochemical fluorination in anhydrous hydrogen fluoride. The resulting products were fully analyzed by NMR spectroscopy. From the reaction balances, literature data and quantum chemical calculations, a new mechanism for carbon-chain isomerization during the electrochemical fluorination (ECF) is proposed. The key step in the formation of isomeric products is believed to be a ring closure reaction involving carbo-cationic or biradical intermediates.     

Vanillin esters of aromatic carboxylic acids in the synthesis of benzo[a]acridine and benzo[b][4,7]phenanthroline derivatives

By condensation of vanillin esters of substituted benzoic acids with 2-naphthylamine and 6-quinolylamines and also with cyclic β-diketones (1,3-cyclohexanedione and dimedone) 2-methoxy-4-(11-oxo-7,8,9,10,11,12-hexahydrobenzo[a]acridin-12-yl)-and 2-methoxy-4-(11-oxo-7,8,9,10,11,12-hexahydrobenzo[b][4,7]-phenanthrolin-12-yl)phenyl benzoates were prepared.     

Hydroxyl radical in aqueous solution: Computer simulation

Molecular dynamics simulations of hydroxyl radical in water are carried out by use of a classical simple point charge extended (SPC/E) water model and a similar point charge model for hydroxyl radical. Structural and dynamical properties are studied along the coexistence curve of SPC/E water at 298, 373, 473, 573, and 633 K and above its critical point at 683, 733, 783, and 833 K with density fixed at 0.3 g/cm3. Dramatic changes in the diffusion dynamics of water and hydroxyl radical near the critical point are related to the reorganization of the three-dimensional structure of water around hydroxyl radical, as revealed by the study of the spatial distribution functions. This study helps us understand the kinetics of oxidation reactions in high-temperature water.     

1-Aryl-1-chloro-2,2,2-trifluoroethylisocyanates—convenient reagents for synthesis of 2-aryl-2-trifluoromethyl-2,3-dihydro-4H-benzo[e][1,3]oxazin-4-ones

1-Aryl-1-chloro-2,2,2-trifluoroethylisocyanates react with 3-alkoxyphenols to form N-(1-aryl-2,2,2-trifluoroethylidene)-O-(3-alkoxyphenyl)urethanes, which undergo intramolecular thermal cyclization into derivatives of 2-aryl-2-trifluoromethyl-2,3-dihydro-4H-benzo[e][1,3]oxazin-4-ones.     

Three component condensation of 6-quinolylamine with aromatic aldehydes and cyclohexyl 1,3-diketones

A three component condensation of 6-quinolylamine with 4-bromo-or 4-methoxybenzaldehyde, and 1,3-cyclohexanedione or dimedone gave 12-(4-bromophenyl)-and 12-(4-methoxyphenyl)-9,9-dimethyl-8,9,10,12-tetrahydro-7H-benzo[b][4,7]phenanthrolin-11-ones. The reaction intermediates obtained were N-arylmethylene-6-quinolylamines, 2-arylmethylenebis(1,3-cyclohexanediones), 3-(6-quinolylamino)-2-cyclohexenone, and 5,5-dimethyl-3-(6-quinolylamino)-2-cyclohexenone. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No 6, pp. 877–885, June, 2007.     

Three-component condensation of 2-naphthylamine with aromatic aldehydes and 5-(2-furyl)-1,3-cyclohexanedione

Three-component condensation of 5-(2-furyl)-1,3-cyclohexanedione with 2-naphthylamine and aromatic or heteroaromatic aldehydes afforded 12-aryl(hetaryl)-9-(2-furyl)-7,8,9,10,11,12-hexahydrobenzo[a]-acridin-11-ones possessing two asymmetric carbon atoms (C⁹ and C¹²). The products were found to be formed as mixtures of diastereoisomers.