Synthesis of New Thieno[2,3-b:5,4-c']dipyridines

We describe the formation of thieno[2,3-b:5,4-c]dipyridines from 5,6-dihydropyridine-2(1H)-thiones. The two-step reaction mechanism was revealed by isolation of an intermediate. The oxo and thioxo groups of the obtained tricyclic compounds were hydrogenated selectively. The structures of all new compounds were elucidated by NMR experiments.     

Chemometric Characterization of Differences in Chromatographic Retention Indices on Standard Polar and Nonpolar Phases as a Criterion for the Group Identification of Organic Compounds

The difference in retention indices on polar and nonpolar phases (RI) has been recommended since 1959 for the gas chromatographic group identification of organic compounds. However, reference data on this parameter for standard phases are presently lacking. To remedy this paradoxical situation at least in part, the paper presents statistically processed data on RI for 226 of the most comprehensively characterized series of compounds. The most important chemometric characteristics of the data sets are considered along with some ways using these values. Contrary to the currently accepted concepts, the additivity of RI values for the majority of series of polyfunctional compounds and their simpler analogues was proved. The main reasons for the absence of such additivity were considered.     

Thermal Behaviour of Metal Complexes of 6-(2-Pyridylazo)-3-acetamidophenol

The present work aims chiefly to study the thermal behaviour of complex compounds with general formula: [M(HL)xH₂O](A)yH₂O (where HL=C₁₃H₁₁N₄O₂=6-(2-pyridylazo)-3-acetamidophenol (PAAP), M=Cu(II), Zn(II), Cd(II) and Fe(III) x=1, 3; y=2, 5) while A=CH₃COO^– (Ac), Cl₂. The second formula is [M(H₂L)xH₂O]Cl₂yH₂O, (where H ₂ L=C₁₃H₁₂N₄O₂ (PAAP), M=Ni(II), Co(II) x=3; y=4, 6). The compounds were identified by elemental analysis, FT-IR spectra and TG/DTG,DTA methods. It was found that during the thermal decomposition of complex compounds water molecules of crystallization are released in the first step. In the next step the pyrolysis of organic ligand takes place. Metal oxide remained as a solid product of the thermal decomposition. Mass spectroscopy has been used for the determination of the thermal decomposition on the intermediate products. It was found that the thermal stability of the studied compounds increases as the ionic radii decreases. The activation energy E, the entropy change S ^*, the enthalpy H ^* change and Gibbs free energy change G ^* were calculated from TG curve.This revised version was published online in November 2005 with corrections to the Cover Date.     

The study of new zinc(II) aliphatic carboxylate complex compounds by methods of thermal analysis

Four new complex compounds were prepared by the reaction of zinc bromobutyrate and organic ligands. The general formula of the synthetized complex compounds are (2-Brbut)₂ZnL and (4-Brbut)₂ZnL₂nH₂O (but=butyrate, L=theobromine (tbr), theophylline (tph), methyl-3-pyridyl carbamate (mpc), n=0-1). The compounds were characterized by chemical analysis and IR spectroscopy. The thermal behaviour of the zinc(II) complexes was studied by thermal analysis. Thermal decomposition in the case of hydrated compounds starts with the release of water molecules. Then molecules of organic ligands and the bromobutyrate anion are released and decomposed. CH₃CH₂CH=O, CO, CH₂=CHCH=O, CH₂O and ZnBr₂ were found as gaseous products of thermal decomposition during heating up to 700°C. IR, mass spectroscopy, X-ray powder diffraction and chemical analysis were used for the determination of solid and gaseous intermediates and products of the thermal decomposition.This revised version was published online in November 2005 with corrections to the Cover Date.     

Transmission of inductive effect and polar resonance effect through the benzene and the furan ring in PMR spectra

Assuming the independence and additivity of the inductive and polar resonance effects, experimental data for chemical shifts in proton magnetic resonance (PMR) spectra of mono and disubstituted benzene and furan derivatives are used to calculate transmission coefficients for the inductive and polar resonance effects due to any substituent for a proton in the 2, 3, or 4 position in the ring. Values of ^* and ^c are tabulated. With benzene compounds transmission of the polar resonance effect decreases on passing from the p and o to the m position. The coefficient of transmission of the inductive effect to a proton in the m or p position is negligible.With furan compounds the values of the coefficient ^c for 2, 5 and 2,4 ring positions are close to the corresponding values for benzene compounds. In the furan ring a considerable part of the polar resonance is transmitted through the heteroatom. The ^* coefficients are appreciably greater with furan than with benzene compounds, because the ring carbon atoms screen the proton less from the substituent. Most of the inductive effect from the 2 to the 5 position in the furan ring is direct (transmitted through space).     

Synthesis of New Thieno[2,3-<Emphasis Type="Italic">b</Emphasis>:5,4-<Emphasis Type="Italic">c</Emphasis>′]dipyridines

Summary. We describe the formation of thieno[2,3-b:5,4-c]dipyridines from 5,6-dihydropyridine-2(1H)-thiones. The two-step reaction mechanism was revealed by isolation of an intermediate. The oxo and thioxo groups of the obtained tricyclic compounds were hydrogenated selectively. The structures of all new compounds were elucidated by NMR experiments.Received December 17, 2002; accepted December 20, 2002 Published online June 2, 2003     

Fluorimetric assay forα-glycolic compounds and other aldehyde precursors

Summary Three reagents and a variety of fluorimetric methods are introduced for the assay of-glycolic compounds, polar olefinic compounds, and olefins. The procedures are based on the controlled oxidation of these compounds to aldehydes and analysis of the aldehydes with J-acid, 2,4-pentanedione, or dimedone. Most of the methods show reasonable sensitivity and accuracy and should be capable of use in air pollution studies. Recommendations are made for their use. Results with these methods confirm the presence of large amounts of-glycolic compounds in aqueous extracts of urban airborne particulates.

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Zusammenfassung Drei Reagenzien und verschiedene fluorimetrische Methoden zur Analyse von-Glykolen, polaren ungesättigten Verbindungen und Olefinen wurden vorgeschlagen. Diese Verfahren beruhen auf der kontrollierten Oxydation der genannten Verbindungen zu Aldehyden und deren Analyse mit J-Säure (Aminonaphtholsulfonsäure), 2,4-Pentandion oder Dimedon. Meistens sind diese Methoden sehr empfindlich und genau; sie dürften sich für das Studium der Luftverunreinigung eignen. Angaben hierfür werden gemacht. Die Ergebnisse bestätigen die Anwesenheit großer Mengen von-Glykolverbindungen in wäßrigen Stadtluftextrakten.

     

Polarographic determination of the protonation rate constants of pyridine and some of its homologs as affected by water

Summary The heights of the catalytic waves in nonbuffer solutions (0.5 M KC1) at 25° have been used to find the rate constants for protonation by water, using the following compounds: Pyridine (5.5 liter/M-sec),-picoline (10.1),-picoline (8.0),-p+icoline (12.5), and ,-lutidine (26). A discussion is given of the effect of steric factors on the protonation rate of these compounds.     

Synthesis and chemistry of dimetallacyclic compounds: Utility ofM(CO)4(η2-alkyne) (M=Ru,Os) building blocks

Low temperature photolysis ofM(CO)₅ (M=Ru, Os) provides efficient synthesis for a variety ofM(CO)₄(²-alkyne) derivatives. The molecules show surprising reactivity toward other 18-electron transition metal carbonyl compounds (M(CO)₅ and CpM(CO)₂,M=Co, Rh, Ir) to give homo- and heterodimetallacyclic complexes. The general features of the condensation reactions are described, the structures of the compounds discussed, and a few illustrative examples of the transformation of the bridging organic units given.     

Novel High Energy Intermediate Analogues with Triazasterol-related Structures as Inhibitors of the Ergosterol Biosynthesis V [1]. Synthesis of Hexahydro-5H-imidazo[1'', 2'': 1,2]pyrimido-[4,3-a]isoquinolines and 1-Alkyl Analogues Representing New 8,13,15-Triazasteroids

Summary. The synthesis of 1,2,6,10b,11,12-hexahydro-5H-imidazo[1,2:1,2]pyrimido[4,3-a]isoquinolines representing new types of 8,13,15-triazasteroids is described. The tetracyclic title compounds were prepared from 4-(2-hydroxyalkylamino)tetrahydro-2H-pyrimidoisoquinolines, which furnish after conversion to the corresponding bromoalkylamino compounds and base-catalyzed intramolecular nucleophilic displacement cyclization of the latter the desired 1-substituted 8,13,15-triazasteroids with aromatic ring A. The structures of the compounds were proved and assigned on the basis of homo- and heteronuclear correlated 1D and 2D NMR experiments. The title compounds represent triaza-analogues of selected high energy intermediates (HEI) of steroidal substrates formed during the enzymatic transformation of squalene into ergosterol and are designed to act as inhibitory mimicries of HEIs and potential antimycotics.Received March 4, 2003; accepted March 7, 2003 Published online June 23, 2003     

Structure of the products of the cyclization in acetic anhydride of β-(2-carboxy-5-chlorophenylamino) propionic acid and its nitrile

-(2-Carboxy-5-chlorophenylamino)propionic acid cyclizes in acetic anhydride to form 4-chloro-2-(2,4-dioxopiperidino)benzoic acid, which subsequently undergoes conversion into its lactone. Under the same conditions, -[acetyl(2-carboxy-5-chlorophenyl)amino]-propionitrile forms 7-chloro-1--cyanoethyl-1,2,3,4-tetrahydroquinoline-2,4-dione. The structures of the compounds obtained were confirmed by their IR, UV, and PMR spectra. An evaluation of the stability of the ketonic and enolic forms of the compounds obtained on the basis of calculations by Hückel's method has been made.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 7, pp. 879–884, July, 1970.     

Structures of three substituted pentacyclo[5.4.0.02, 6.03, 10.05, 9]undecanes and a computational analysis of bond lengths

5-Methyl-2-phenylpentacyclo[5.4.0.0^{2, 6}.0^{3, 10}.0^{5, 9}]undecane-8, 11-dione,5-methyl-2-phenylpentacyclo [5.4.0.0^2,6.0^3,10.0^5,9]undecane-8-one-11-ol,and 5-methyl-2-phenylpentacyclo[5.4.0.0^2,6.0^3,10.0^5,9]undecane-8,11-diol are three cage compounds which differ only in the oxidation state at C(8) and C(11). The three compounds contain a four-membered, a six-membered, and four five-membered rings fused into a cagelike structure. An X-ray structure analysis shows the C(1)-C(7) and C(9)-C(10) bonds in the diketo cage to be 1.606(2) and 1.586(2) Å, which are significantly longer than in the other two molecules. In order to assess the effects of strain, steric, and electronic factors in these compounds, we investigated the unsubstituted parent cage compounds and a series of derivatives by molecular mechanics (MM3), AMPAC (AM1), MOPAC (PM3), and GAUSSIAN 90 calculations. These data suggest that dipolar through space interactions are responsible for the bond elongation and not a _– ^* interaction, which has been postulated in parallel-systems originating from a common bond. A small degree of _– ^* through-bond interaction may contribute to the lengthening in the dimethylene cage analogues.     

Synthesis of Cationic Cholesterol Derivatives with Succinyl Spacer Group

Syntheses of N,N,N-trimethyl[2-(3-cholesteryloxy)syccinyloxyethyl]ammonium iodide, N,N-dimethyl-N-2-hydroxyethyl[2-(3-cholesteryloxy)syccinyloxyethyl]ammonium iodide, and N-[(3-cholesteryloxy)syccinyl]piperazine were performed. The compounds synthesized in a liposomal form may be used for delivery of genetical material into cells.     

Amino Acid Derivatives as Protein Side-Chain Model Compounds: The Partial Molar Volumes and Heat Capacities of Some N-Acetyl-N′-methyl Amino Acid Amides in Aqueous Solution

The partial molar heat capacities, C ^o _p,2, and partial molar volumes, V ^o ₂, at infinite dilution have been determined for the compounds N-acetyl-N-methylglycinamide, N-acetyl-N-methylalaninamide, N-acetyl-N-methylvalinamide, and N-acetyl-N-methylleucinamide in aqueous solution at the temperatures 15, 25, 40, and 55°C. The C ^o _p,2 and V ^o ₂ results have been used to calculate amino acid side-chain contributions to the thermodynamic properties. These side-chain contributions are compared with those derived in previous work using thermodynamic data for the corresponding acetylated primary amides and with results reported using peptide model compounds.     

Furan acetal compounds

A method was developed for the preparation of amino derivatives of 1,3-dioxanes of the furan series by amalgam reduction of the corresponding nitro compounds. This method makes it possible to obtain amino compounds without destruction of the furan and dioxane rings. 2--Aminofuryl-5-alkyl-5-methylol- and 5--aminofuryl-5,5-bis(chloromethyl)-1,3-dioxanes and their azomethines were synthesized for the first time.See [5] for communication III.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 440–442, April, 1971.     

Optisch aktive aromatische Spirane, 18. Mitt.: Darstellung von optisch aktiven 4,4′-disubstituierten 2,2′-Spirobi-s-hydrindacenen

Summary All optically active title compounds were obtained from the 4,4-diacetyl-spiro compound2; (+)- and (–)-2 were accessible by chromatography on triacetyl cellulose in ethanol. The enantiomeric purities were established from chromatographic data. The chirality (–)-(2R) was deduced for all new compounds on the basis of the CD spectra of (–)-2 and (–)-2,2-spirobi-(5,6,7,8-tetrahydrobenzo[f]indane). From the molar rotations of these 4,4-disubstituted 2,2-spirobiindanes (empirical) ligand parameters were determined (using the so-called shortened approach). Generally, the values of in these compounds are higher than those of the analogous tetrahydrobenzoindane derivatives.

Herrn Prof. Dr.F. Sauter mit besten Wünschen zum 65. Geburtstag gewidmet     

Heterocyclic analogs of pleiadiene

The corresponding 1--dialkylaminoethylperimidines were obtained by the action of -dialkylaminoethyl chloride hydrochlorides on perimidines in alkaline media. Some of the compounds obtained form substituted 2-aminoperimidines and 2-perimidone on reaction with sodium amide or alkali. 2-Morpholino- and 2-piperidino-1-methylperimidines are obtained from 1-methyl-2-chloroperimidine and morpholine or piperidine. The synthesized compounds have weak bacteriostatic, fungistatic, and tuberculostatic activity.See [1] for communication X.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 418–421, March, 1974.     

CH bond dissociation energies,isolated stretching frequencies,and radical stabilization energy

An earlier correlation between isolated CH stretching frequencies, v, and experimental CH bond dissociation energies, in hydrocarbons, fluorocarbons, and CHO compounds, is updated. A stabilization energy, E, which reflects only the properties of the radical, is defined by the deviation of a point from the above correlation. E values for a variety of radicals are listed and discussed. In H? C? N and H? C? O compounds E is low or negligible, due to the low v found in these compounds. The conventional definition of E_S then represents a serious misnomer, which distracts attention from the probable source of discrepancies between experimental and ab initio values of DH°(C? H), namely, the parent molecules. Stereo electronic effects concerned with the breaking of CH bonds are predicted in a variety of situations. Some experimental determinations of DH°(C? H), viz., in C₂H₄, HCOOH, CH₃CHO, CH₃NH₂, are considered to be probably in error. Schemes for partitioning energies of atomization into ‘standard’ or ‘intrinsic’ bond energies are criticized.     

Host-guest binding in two coordinatoclathrates of 1,1′-binaphthyl-2,2′-dicarboxylic acid. x-ray crystal structures of the inclusion compounds with 1-propanol (2 : 1) andt-butanol (1 : 1)

1,1'-Binaphthyl-2,2'-dicarboxylic acid (1) forms crystalline inclusion compounds with 1-PrOH (2:1) andt-BuOH (1:1). X-ray crystal structures of the two inclusion compounds are reported. Crystals of1·1-PrOH (2: 1) show triclinic ( ) symmetry with the unit cell dimensionsa = 10.160(1),b = 14.050(2),c = 15.167(1) Å = 100.37(1), = 104.40(1), and =94.82(1)°. Crystals of1s·t-BuOH (1: 1) are monoclinic (P2₁/n) with the cell dimensionsa = 10.603(5),b = 14.377(4),c = 15.664(7) Å, = 104.24(4)°. In both structures, H-bonded loops involving host –000H functions and guest –OH groups establish the supramolecular association. They relate these coordinatoclathrates to previous alcohol inclusions of1. Due to the unusual 2:1 (host: guest) stoichiometry, additional dimer-like interactions between –000H groups of host molecules are found in the 1-PrOH inclusion compound. From the point of view of topology these structures can be referred to as channel inclusion compounds.