Synthesis of 2-Acetamido-5,6-dihalophenyl Acetates

Summary.  2-Acetamido-5,6-dihalophenyl acetates were synthesized as intermediates for the preparation of 6, 7-dihalo-8-quinolinols via the Skraup procedure. Received January 24, 2000. Accepted February 12, 2000     

Synthesis of Enantiopure Chiral Perhydrobenzimidazole and Hexahydroquinoxaline Derivatives

Summary.  Starting from 2-anilino-2-ethoxy-3-oxothiobutyric acid anilides and (R, R)-or (S, S)-trans-1,2-diaminocyclohexane, chiral C2-disubstituted perhydrobenzimidazole and trans-4a,5,6,7,8,8a-hexahydroquinoxaline derivatives were obtained depending on the polarity of the solvent. Received April 10, 2000. Accepted May 2, 2000     

Regioselective Synthesis ofPyrano[3,2-f]quinolin-2(7H)-onesand Furo[3,2-f]quinolin-2-ones

Summary.  A simple and efficient synthesis of the hitherto unreported ring systems pyrano[3,2-f]quinolin-2(7H)-one and furo[3,2-f]quinolin-2-one was accomplished via a thermal [3,3]-sigmatropic rearrangement. Received March 7, 2000. Accepted May 4, 2000     

Environmentally Friendly Arylmethylation of Aromatics with Benzyl Halides Using Envirocat EPZ10® as the Catalyst

Summary.  The Friedel-Crafts arylmethylation of aromatics with benzyl halides or bis-(bromomethyl)-benzene in the presence of Envirocat EPZ10? affords selectively para-arylmethylated products in good yields. Isolation of pure products involving an eco-friendly procedure and recyclability of the catalyst are important features of this method. Received January 17, 2000. Accepted (revised) March 2, 2000     

An Anionic Mn(III) Ethyleneglycolate Complex

Summary.  The crystal structure of consists of individual layers in which the anionic complexes form strings of vertex-sharing octahedral units. These strings are interconnected by units to form layers via Na-Cl and Na-O interactions. An outstanding feature of the compound are the unusually strong Jahn-Teller elongated trans- octahedra. Received April 25, 2000. Accepted May 8, 2000     

Valence 4p functions for the first-row transition metal atoms

For the valence 4p orbitals of the first-row transition metal atoms Sc through Zn, Gaussian-type basis functions are developed referring to excited 3d ^m 4s ¹4p ¹ electronic configurations. Molecular tests of the present work 4p sets are performed for the Cu atom, the diatomic Cu₂ molecule, and Cu₉ and Cu₁₃ clusters, and the results are compared with those from two literature sets. Received: 17 January 2000 / Accepted: 30 May 2000 / Published Online: 11 September 2000     

Evaluation of molecular moments by three methods

The three evaluative methods of the moment by means of the coefficient a_k of the HMO characteristic polynomial, the tree graph, and walk graph have been studied. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 78: 237–244, 2000     

Regioselectivity in the Reactions of Bis-hydrazonoyl Halides with Pyrimidine-2-thiones

Summary.  Bis-hydrazonoyl chlorides react regioselectively with pyrimidine-2-thiones, which contain a masked thiourea residue, to give the hitherto unknown annelated 2,3-bis-arylhydrazono-thiazoles and 3,3′-bis-1,2,4-triazoles. Reaction of bis-hydrazonoyl chlorides with 2-methylthio derivatives gave only 3,3′-bis-1,2,4-triazoles. Received October 4, 2000. Accepted (revised) December 20, 2000     

Calculation of overlap integrals over Slater-type orbitals using translational and rotational transformations for spherical harmonics

Using translation and rotation formulas for spherical harmonics the finite sums through the basic overlap integrals and spherical harmonics are derived for the arbitrary overlap integrals over Slater-type orbitals (STOs). The recurrence relations for the evaluation of basic overlap integrals have been established recently [Guseinov II, Mamedov BA (1999) J Mol Struct (THEOCHEM) 465:1]. By the use of the derived expressions the overlap integrals can be calculated most efficiently and accurately, especially for large quantum numbers of STOs. Received: 2 May 2000 / Accepted: 31 May 2000 / Published online: 11 September 2000     

Thiochromenone-Annelated Heterocycles: Regioselective Synthesis of Furo[3,2-b]-thiochromen-9-ones

Summary.  A number of hitherto unreported furo[3,2-b]thiochromenone derivatives were regioselectively synthesized in good yields starting from 3-allyloxy-thiochromenones. Received September 18, 2000. Accepted (revised) November 15, 2000     

Solvent-Free Aminoalkylation of Phenols and Indoles Assisted by Microwave Irradiation

Summary.  Phenols and indoles were aminoalkylated in a solvent-free and environmentally friendly Mannich reaction on acidic alumina assisted by microwave irradiation in good overall yields. Received November 10, 2000. Accepted December 6, 2000     

A Sequence of Aldol Condensations and a Michael Addition Giving a Cyclohexenone Ring System

Summary.  The reaction of 1,5-diphenylpentanetrione, 4-chlorobenzaldehyde, and acetone in the presence of methylamine resulted in 2,6-dibenzoyl-5-(4-chlorphenyl)-3-methyl-cyclohex-2-en-1-one, which was formed by a sequence of a Knoevenagel reaction, an aldol condensation, and a Michael addition in a one-pot reaction. Received August 16, 2000. Accepted September 8, 2000     

Epoxidation of (Z)-3-Arylidene-1-thioflavanones

Summary.  Epoxidation of (Z)-3-arylidene-1-thioflavanones by sodium hypochlorite or alkaline hydrogen peroxide afforded diastereomeric mixtures of trans,cis- and trans,trans-epoxides. These were separated by silica gel column chromatography. Determination of the isomeric composition of the crude reaction products and structure elucidation of all new isolated epoxides were performed by ¹H and ¹³C NMR spectroscopy. Received November 10, 2000. Accepted December 19, 2000     

Many‐particle Dirac identities for arbitrary elementary spins

The eigenvalues of arbitrary conjugacy class‐sums of the symmetric group, within subspaces that contain irreducible representations with at most k rows, are considered. Explicit expressions for these eigenvalues in terms of the eigenvalues of single‐cycle class‐sums with cycle lengths up to k are obtained. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 78: 407–411, 2000     

Stereospecific Synthesis of D-Glycero-D-ido-oct-2-ulose

Summary.  D-Glycero-D-gulo-heptose reacted with 2,2-dimethoxypropane to give its 2,3:6,7-di-O-isopropylidene derivative. Its base-catalyzed addition to formaldehyde resulted in the formation of 2,3:6,7-di-O-isopropylidene-2-C-(hydroxymethyl)-D-glycero-D-gulo-heptofuranose. After acid hydrolysis of this aldolization product, a new branched-chain aldose, 2-C-(hydroxymethyl)-D-glycero-D-gulo-heptose, was obtained, which was stereospecifically rearranged under the catalytic action of molybdic acid to D-glycero-D-ido-oct-2-ulose. Received October 17, 2000. Accepted December 4, 2000     

Strategies for computing chemical reactivity indices

 Two recent articles [(2000) J Am Chem Soc 122: 2010, (2001) J Am Chem Soc 123: 2007] have explored electron-density-based and external-potential-based chemical reactivity indices. In this article, methods are presented for computing these indices from the output of a Kohn–Sham density functional theory calculation. Received: 18 October 2000 / Accepted: 4 April 2001 / Published online: 9 August 2001     

Lack of Linear Free Energy Relationships in the p-Toluenesulfonic Acid Mediated Chromium(VI) Oxidation of Organic Sulfides

Summary.  The oxidation of methylphenyl sulfide by imidazolium dichromate in acetonitrile mediated by p-toluenesulfonic acid is first order in IDC and TsOH and zero order in MeSPh in the concentration range studied. The IDC oxidation of 14 para-, meta-, and ortho-substituted phenylmethylsulfides at 20–45°C conforms to the isokinetic relationship but not to any of the linear free energy relationships; the isokinetic temperature lies within the experimental temperature range. Received April 18, 2000. Accepted (revised) July 12, 2000     

Polycyclic 2H-Pyran Derivatives by Intramolecular Hetero-Diels-Alder Reactionsof a-Sulfur-Substituted a,b-UnsaturatedCarbonyl Compounds

Summary.  Reaction of 1-(phenylsulfenyl)-, 1-(phenylsulfinyl)-, and 1-(phenylsulfonyl)-2- propanones as well as 2-(phenylsulfonyl)-acetophenone with 2-(3-methyl-2-butenyloxy)- and 2-((E)-3-phenyl-2-propenyloxy)-benzaldehydes yielded the corresponding Knoevenagel condensation products. The latter compounds underwent intramolecular cycloadditions affording cis-fused 2H-pyran derivatives as the major products. Received June 29, 2000. Accepted July 18, 2000     

Voltammetric trace analysis of DNA and RNA

A voltammetric determination of DNA/RNA is described. The new aspect is the use of the extracellular endonuclease Serratia marcescens in the sample preparation. Using this enzyme it is possible to determine DNA/RNA with a detection limit of 2–5 pg/mL. This satisfies the requirements of the WHO and the FDA. Received: 16 May 2000 / Revised: 21 July 2000 / Accepted: 23 July 2000     

Microwave Activated Solid Support Synthesis of New Antibacterial Quinolones

Summary.  A novel synthesis of 6-fluoro-7-(5-aryl-1,3,4-thiadiazol/oxadiazol-2-yl-sulfanyl)-4-quinolone-3-carboxylic acids from 7-chloro-6-fluoro-4-quinolone-3-carboxylic acid and 5-substituted 1,3,4-thiadiazoles/oxadiazoles on basic alumina under microwave activation is described. All compounds were screened for their in vitro antibacterial activity against B. lichenformis, 2689, K. aerogens 2281, S. typhimurium 2501, E. herbicola 2491, and P. vulgaris 2027 and found to possess activities comparable to that of the standard drug norfloxacin. Received May 2, 2000. Accepted (revised) June 13, 2000