Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Volume 60 , Issue 2
Showing 1-50 articles out of 80 articles from the selected issue
  • Michio Kimura
    1987 Volume 60 Issue 2 Pages 447-451
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The reaction of enamine between 9-chloroacridines and 6-aminouracil derivatives give novel acridine substituted uracils, the structures of which have been determined by means of an X-ray analysis of 5-(acridin-9-yl)-6-amino-1,3-dimethyluracil hydrochloride dihydrate, C19H16N4O2·HCl·2H2O. The crystal is triclinic with a space group P\bar1; also, a=8.763(3) b=16.130(9), c=7.620(2) Å, α=117.51(4), β=83.81(3), γ=94.21(4)°, Z=2, V=949.3 Å3, Dc=1.16 g cm−3, and μ=5.30 cm−1 for CuKα. The structure was solved by a direct method and refined by a block-diagonal least-squares procedure: R=0.074 for 2810 reflections with |Fo|>3σ(|Fo|). The crystal is composed of the title compound, chloride anion, and two molecules of water held together by hydrogen bonds (described in Table 4).
  • Kazuo Sugiyama, Hiroshi Miura, Yasushi Nakano, Hidehiro Suzuki, Tsuneo ...
    1987 Volume 60 Issue 2 Pages 453-456
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The liquid-phase hydration of acrylonitrile to acrylamide was examined over a manganese dioxide catalyst at 65 °C. When the catalysts were treated at 110–500 °C, both the acidity and the reaction activity of the catalysts decreased at temperatures above 110 °C. The reduction of the solid acidity of heat-treated samples decreased the catalytic activity of the catalysts. It was confirmed that the solid acidity of manganese dioxide was derived from acidic hydroxyl groups on the catalyst surface through their dispersion in water. A good relationship between the number of surface hydroxyl groups and the catalytic activity of the manganese dioxide was observed; its hydration ability was depressed by the addition of an aqueous base as a NaOH solution. These results show that the acidic surface hydroxyl group of a manganese dioxide catalyst is the active site of acrylonitrile hydration. The kinetic behavior of both acrylonitrile and water was examined and the reaction rate snowed both first and zero orders with respect to the acrylonitrile and water concentration, respectively. The hydration mechanism of acrylonitrile on the manganese dioxide catalyst is discussed.
  • Hideaki Fujiwara, Hiroyuki Arakawa, Saburo Murata, Ikuzi Ohtaku, Motok ...
    1987 Volume 60 Issue 2 Pages 457-462
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    A complex-formation reaction has been studied for the Me2SnCl2 plus pyridine system in dimethyl phthalate (DMP) and dioctyl phthalate (DOP) by means of titration calorimetry. The resulting entropy changes in the reactions of A+B=AB and AB+B=AB2, with A=Me2SnCl2 and B=pyridine, were compared with those calculated for the gas-phase reactions. The values in solution amounted only to 1/3–1/4 of the gas-phase values. Correction for the entropy of solution of each component failed to explain the observed values in the absence of a strong solvation. The solvation model is presented to allow for such a discrepancy, assuming a strong solvation for Me2SnCl2 as well as for the 1:1 pyridine complex by definite numbers of solvents. To test the applicability of the model, calculations were made based on molecular statistical thermodynamics. The results obtained were reasonable, indicating that a free molecule, Me2SnCl2, is solvated by 1.3 molecules of the solvent of DMP, which are released about half by half on the formation of the 1:1 and 1:2 complexes with pyridine.
  • Setsuko Sato, Daiyu Nakamura
    1987 Volume 60 Issue 2 Pages 463-466
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Two phase transitions were located for solid [(CH3)4N]GaBr4 at 404 and 138 K. The temperature dependences of 1H NMR spin-lattice relaxation times were determined mainly at 20 MHz. A shallow 1H T1 minimum appearing at ca. 400 K and a deep one below ca. 250 K were observed. The latter minimum could be explained by the occurrence of the overall reorientation of the cation as a whole with an activation energy of 14.5 kJ mol−1. The shallow 1H T1 minimum may come from temperature dependent quadrupolar relaxation of bromine nuclei through the dipolar relaxation of the second kind.
  • Hiroyuki Ishida, Ryuichi Ikeda, Daiyu Nakamura
    1987 Volume 60 Issue 2 Pages 467-474
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The temperature dependences of the second moment of 1H NMR absorptions, the 1H spin-lattice relaxation time, T1, and the 1H spin–spin relaxation time, T2, of CH3NH3ClO4 (CH3ND3ClO4) were observed in the three solid phases existing over a wide range of temperature. In the phase I stable above 451 K, the onset of the isotropic reorientation as well as the self-diffusion of the cations with the activation energy of 36 kJ mol−1 was observed. In the phase II stable between 451 and 321 K, no remarkable change in the motional state of the cation was observed, but the dynamical orientational disorder of perchlorate anions was expected to occur. In the phase III stable below 321 K, the correlated reorientation defined as the C3 reorientation of the cation having the rigid structure, was observed at lower temperatures for two nonequivalent cations in the crystal with small activation energies of 4.4 and 2.0 kJ mol−1. The uncorrelated reorientation in which both CH3 and NH3+ groups perform C3 reorientation independently could be observed at a higher temperature with the activation energy of 6.4 kJ mol−1. Nonexponential behavior appearing in the observation of T1 below 40 K could be explained by the presence of a contribution to 1H T1 from the rotational tunneling of the cation.
  • Kazuo Tokiwano, Kiyoshi Arakawa
    1987 Volume 60 Issue 2 Pages 475-481
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    A molecular dynamics simulation has been performed for a fluid system containing 1000 water molecules confined to a cubical box at mass density 1 g cm−3, where the ST2 type intermolecular potential has been used. Newtonian equations of motion of molecules were solved according to the method of constraints proposed by Ryckaert et al. Atomic radial distribution functions and corresponding partial structure functions at 24 and 93 °C were given and compared with theoretical calculations for the pentamer–monomer mixture model and neutron diffraction data. The agreement among the three was found to be satisfactory on the whole. In order to investigate how profoundly the periodic boundary condition influences upon the calculated values, the difference between the hydrogen-bonding behavior of molecules near the boundary and that of those in the central part of the box was examined into details. The population of hydrogen bonds near the boundary was found to be about 10% lower than that in the central part including about 210 molecules. In addition to these static properties the self-diffusion process was investigated.
  • Jun Yamauchi, Keiichi Okada, Yasuo Deguchi
    1987 Volume 60 Issue 2 Pages 483-487
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The ENDOR spectra of diphenyl nitroxide (DPNO) and its monomethyl derivatives were observed in ethylbenzene at −70 °C. The agreement between the ESR and ENDOR data is generally good. The MO calculations, however, indicate a few disagreements in the case of the m- and o-methyl DPNO derivatives. The methyl substitution at the meta-position destroys the equivalency of all protons at the meta-positions, which are divided into two sets of equivalent proton groups of the same number. The ortho-substitution weakens the coplanarity of the two benzene rings and increases the number of the equivalent proton groups, which are fully resolved in the ENDOR spectrum. The steric hindrance is taken into account in the MO calculation, which can predict these slightly different coupling groups-again except for those in the meta-positions. A satisfactorily simulated spectrum of the o-methyl DPNO is obtained on the basis of the ENDOR data.
  • Woo-Sik Jung, Hiroshi Tomiyasu, Hiroshi Fukutomi
    1987 Volume 60 Issue 2 Pages 489-492
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    17O nuclear magnetic relaxation times and chemical shifts of uranyl oxygen atoms (hereafter uranyl oxygens) and solvent water have been measured with changing concentration of the uranyl ion in aqueous solution. The 17O resonance of the water molecule in the first-coordination sphere is determined to be at 90.1±1.2 ppm relative to free water at 25 °C. The effective correlation time for the 17O quadrupolar relaxation of the coordinated water, which corresponds to the reorientation time for the hydrated uranyl ion, is about 8.7 times that of free water. The 17O spin-lattice relaxation times (T1) of uranyl oxygens have been measured at 25 °C. From the 17O T1 values the 17O nuclear quadrupole coupling constant of uranyl oxygens has been estimated to be 0.44 MHz. This small value implies the high symmetry of electron distribution around uranyl oxygens.
  • Masaru Nakahara, Masanobu Zenke
    1987 Volume 60 Issue 2 Pages 493-496
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The conductance of potassium iodide was measured in water as a function of concentration (between 2×10−3 and 10−2 mol dm−3) and temperature (between −6 and 0 °C). The effect of temperature on the mobility of such halide ions as I and Cl ions was discussed by taking the ionic residual friction coefficient Δζ, which was defined as the overall friction coefficient subtracted by the Stokes one for slip, instead of the conventional Walden product. We compared the experimental results with the predictions due to the Hubbard–Onsager dielectric friction theory. Of the monovalent ions so far studied, the iodide ion shows the largest negative value of Δζ with the largest positive temperature coefficient; their signs are opposite to those theoretically predicted. These findings were explained in terms of the special ionic transport mechanism called the passing-through-cavities.
  • Kazuaki Harata, Kaneto Uekama, Masaki Otagiri, Fumitoshi Hirayama
    1987 Volume 60 Issue 2 Pages 497-502
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Hexakis(2,3,6-tri-O-methyl)-α-cyclodextrin (methyl-α-CDx) forms crystalline inclusion complexes with (S)-mandelic acid (S-MA) and (R)-mandelic acid (R-MA). Both crystals are monoclinic, and the space group is P21 with cell dimensions: a=13.123(2), b=23.187(4), c=13.113(2) Å, β=107.19(1)° for the S-MA complex, a=11.624(2), b=23.739(4), c=13.786(2) Å, β=106.56(1)° for the R-MA complex. The structures were solved by inspection of a Patterson map and the R-map method, and refined by the block-diagonal least-squares method to the R-values of 0.087 for the S-MA complex and 0.055 for the R-MA complex. In the S-MA complex, the methyl-α-CDx molecule, which has a pseudo two-fold symmetry, loosely includes the phenyl group of S-MA. The hydroxyl and carboxyl groups of S-MA protrude from the O(2), O(3) side of the methyl-α-CDx cavity and form hydrogen bonds with water molecules located outside the host cavity. The methyl-α-CDx molecule in the R-MA complex tightly binds the R-MA molecule which is deeply inserted into the host cavity. The hydroxyl group of R-MA is hydrogen-bonded to an O(2) oxygen atom of host methyl-α-CDx. The comparison of the two structures suggests that the complex formation induces the conformational change of the host molecule to accommodate S-MA or R-MA more suitably within the cavity.
  • Noriko Itoh, Tetsur\={o} Nakamura
    1987 Volume 60 Issue 2 Pages 503-507
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The simultaneous vaporization of dopants in aluminoborosilicate glass was investigated by means of mass spectrometry using a Knudsen cell. The detected chemical species were Na, K, Ni, Zn, Rb, Ag, Te, TeO2, and Cs in the temperature range of 650–800°C. Their vapor pressures were 10−6–10−4 Pa. The activation energy of vaporization was discussed in relation to the electrostatic force between the vaporizing specie and oxygen. However, lithium, alkali-earth metal elements, alomst all the transition metal elements (such as Fe, Cr, and Ru), and rare-earth metal elements were not detected in the vapor phase, though they were contained in the glass matrix.
  • Masashi Hojo, Yoshihiro Akita, Kazukiyo Nishikawa, Yoshihiko Imai
    1987 Volume 60 Issue 2 Pages 509-515
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The polarographic reductions of acetic, benzoic, p-toluenesulfonic, and perchloric acids have been examined in pyridine solutions with tetrabutylammonium, tetraethylammonium, sodium, and lithium perchlorate as the supporting electrolytes. The difference in the half-wave potentials of the acids was explained in terms of the difference in the degree of interaction between the pyridinium ion and the conjugate bases (e.g., CH3COO) made of the acids. The alkali-metal ions interact with the acetate or benzoate ion to form RCOO(M+)2 (M=Li and Na). The formation constants of RCOO(M+)2 were evaluated by means of the positive shift in the half-wave potential of the pyridinium ion in the presence of a large excess of the alkali metal ions. Substituted acetic and benzoic acids and phenols were also examined so as to ascertain the effect of the substituent groups.
  • Isao Sanemasa, Yoshiko Miyazaki, Seiji Arakawa, Masaya Kumamaru, Toshi ...
    1987 Volume 60 Issue 2 Pages 517-523
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The solubility in water at 25.0°C of benzene–hydrocarbon binary mixtures has been studied for different ratios between benzene and toluene, ethylbenzene, (o-, m-, p-)xylene, propylbenzene, chlorobenzene, and cyclohexane. Aqueous solutions saturated with mixed solutes were prepared by making use of the solute vapor. The solubility of individual constituent in the binary mixture was found to change linearly with mole fraction over a whole range of the composition. This is not the case for the benzene–cyclohexane system: the solubility of each component deviates positively from the linear change of solubility with composition. The solubility of each component of benzene–1-octanol mixture in water was also measured by adding the mixture of various compositions directly to water. The positive deviation for the solubility of each component was observed. The relationship between the 1-octanol/water partition coefficient of a solute and the aqueous solubility of pure liquid solute which forms a nonideal solution in 1-octanol was discussed.
  • Hiroshi Nakazawa, Hisaka Ohtsuru, Hayami Yoneda
    1987 Volume 60 Issue 2 Pages 525-530
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Three geometrical isomers of [Co(edda)(aa)] where edda=N′,N-ethylenediaminediacetato, aa=glycinato (gly), β-alaninato (β-ala), have been synthesized and characterized. They have been completely resolved into the enantiomers, except unsym-cis-fac-[Co(edda)(β-ala)], by the bis(μ-d-tartrato)diantimonate(III) anion, [Sb2(d-tart)2]2−, form of QAE-Sephadex resin with water as the eluent, and their absolute configurations have been determined based upon the circular dichroism spectra. It has been revealed that the Δ enantiomer is favored more by [Sb2(d-tart)2]2− than the Λ enantiomer irrespective of the kind of the geometrical isomers. Consideration on the mechanism of the optical resolution has been presented.
  • Shin-ichi Ishiguro, Kazuhiko Ozutsumi, Hitoshi Ohtaki
    1987 Volume 60 Issue 2 Pages 531-538
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Complexation of Ni(II) and Zn(II) with Cl ions has been studied by calorimetry and spectrophotometry in N,N-dimethylformamide (DMF) containing 0.4 mol dm−3 (C2H5)4NClO4 as a constant ionic medium at 25 °C. Calorimetric titration curves obtained in each system were well-explained in terms of formation of [MCln](2−n)+ (n=1–4 and M2+=Ni2+ or Zn2+), and their formation constants, enthalpies and entropies were determined. Formation of the nickel(II) chloro complexes in DMF was also supported by spectrophotometry. In the nickel(II) chloride system, the stepwise enthalpy ΔH3° and entropy ΔS3° values are remarkably large and positive as compared with the ΔHn° and ΔSn° (n=1, 2, and 4) values. Individual electronic spectra of nickel(II) ion, [NiCl]+ and [NiCl2] are significantly different in both intensities and peak positions from those of [NiCl3] and [NiCl4]2− over the range 300–850 nm. These thermodynamic and spectrophotometric results were explained in terms of formation of the octahedral [NiCl]+ complex as well as [Ni(dmf)6]2+ and of formation of the tetrahedral [NiCl3] and [NiCl4]2− complexes in DMF. On the other hand, in the zinc(II) chloride system, the ΔSn° (n=1 and 2) values are large and positive, but the ΔSn° (n=3 and 4) values are significantly small. The corresponding ΔHn° (n=1 and 2) values are positive but the ΔHn° (n=3 and 4) values are significantly negative. It is thus postulated that the [ZnCln](2−n)+ (n=2 and 3) complexes have the tetrahedral coordination structure as well as the [ZnCl4]2− complex in DMF.
  • Michio Nakamura, Hisashi Okawa, Tasuku Ito, Masako Kato, Sigeo Kida
    1987 Volume 60 Issue 2 Pages 539-543
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    1:3-Cobalt(III) complexes of 3-substituted 1-phenyl-1,3-propanediones (C6H5–CO–CH2–CO–R) have been synthesized, and their stereoselectivities were studied with 400 MHz proton NMR spectroscopy. When the substituent (R) was ethyl, propyl, isopropyl, butyl, or isobutyl, the complexes were obtained in a mixture of fac and mer isomers with the fac/mer ratio of 1/3, demonstrating statistical distribution. When the substituent was t-butoxymethyl or cyclohexyloxymethyl the fac isomer was predominantly formed. The stereoselectivity in the geometrical isomer formation of the complexes was ascribed to the interligand CH/π-interaction occuring between the R group and the phenyl ring. The stereoselectivities of the complexes [Co(l-moba-X)3] (l-moba-X=4-(l-menthyloxy)-1-(p-X-phenyl)-1,3-butanedionate ion; X=H, Br, CH3) were also examined by means of 1H NMR spectroscopy and compared with the CD spectral result previously reported.
  • Yukio Sakai, Masahiro Shinmura, Hajime Otsuka, Makoto Takagi
    1987 Volume 60 Issue 2 Pages 545-549
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Extraction behavior of alkali and alkaline earth metal cations was investigated with a new extractant derived from polyethylene glycol mono[4-(1,1,3,3-tetramethylbutyl)phenyl]ether (Triton X-100; average number of oxyethylene group, 10) by introducing a phenolic(2-hydroxy-5-nitrobenzyl) group at the hydroxyl terminal of the polyethylene glycol chain. Alkali metal cations were extracted into 1,2-dichloroethane by forming 1:1 complex with the extractant. The overall extraction constant sequence was K+(10−9.15)>Rb+(10−9.26)>Cs+ (10−9.28)>Na+ (10−10.08)>Li+(10−10.36). The selectivity for K+, Na+, and Li+ was discussed by comparing the extraction behavior with a mixture of nonionic surfactant or dicyclohexano-18-crown-6 and a proton-dissociable lipophilic dye. For alkaline earth metal cations, the extractability decreased in the order Ba2+>Sr2+>Ca2+>>Mg2+. The metal extractability strongly depended on the nature of the anion in the aqueous phase.
  • Yoshiyuki Ohki, Yasuo Suzuki, Mamoru Shimoi, Akira Ouchi
    1987 Volume 60 Issue 2 Pages 551-556
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The title complex was synthesized, and its crystal and molecular structures were determined by the single-crystal X-ray-diffraction method. It is triclinic, with the space group of P\bar1; the cell constants are a=20.621(4), b=22.288(5), c=7.724(1) Å, α=93.30(2), β=96.78(2), γ=107.43(2)°, Z=4, and the final R value is 0.048. Although there are two kinds of crystallographically independent complexes, their structures are almost the same, with only a slight difference in the orientations of the naphthalene rings of the ligands. Both of the central metal atoms are ennea-coordinated and are in the tricapped trigonal-prism geometry: two carboxylato ligands make four-membered chelate rings, and they are also ligated five water oxygen atoms. No carboxylate ions bridge the metal atoms, but the oxygen atoms of the ligands, isolated carboxylate ions, and the crystalline water molecules are linked through hydrogen bondings along the bc-plane. The metal atoms lie on a plane parallel to (100), and the planes are separated by the layers of the naphthalene rings of the naphthoate ions.
  • Yong Li, Kunihiko Tajima, Kazuhiko Ishizu, Nagao Azuma
    1987 Volume 60 Issue 2 Pages 557-562
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    In the presence of the optimum amount of water, the copper(II) ion and 15-crown-5 (15C5) derivatives gave the dihydrated complex in boron trifluoride–diethyl ether (BF3–ether). Based on optical and ESR spectrometric titrations, we found that the crown ether captures the copper(II) ion in the equivalent metal/ligand molar ratio. The d–d band absorptions of the complexes were detected in the near-infrared region. The complexes revealed the characteristic ESR g-anisotropies (gz<gx, gy) which are typical of the copper(II) complexes with a 3dz2 ground-state doublet. The superhyperfine splittings due to the 17O isotope was successfully detected, and the fact of the axial ligation of the water molecule was demonstrated. The ESR parameters were determined by means of the computer simulation of the line shape, while the copper-ligand bonding parameters were estimated from the ESR parameters by means of Bleaney’s calculation.
  • Kunio Ishikawa, Shunichi Fukuzumi, Toshio Tanaka
    1987 Volume 60 Issue 2 Pages 563-570
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The thermal cleavage of the cobalt–carbon bond of cis-dialkylcobalt(III) complexes, cis-[R2Co(bpy)2]+(R=Me, Et, and PhCH2; bpy=2,2′-bipyridine), was enhanced by the presence of benzyl and allyl bromide, inducing the C–C bond formation to yield mainly 1,2-diphenylethane and 1,5-hexadiene, respectively. In the cis-[(PhCH2)2Co(bpy)2]+-allyl bromide system, a comparable amount of the cross-coupling product (4-phenyl-1-butene) was obtained together with the homo-coupling products (1,2-diphenylethane and 1,5-hexadiene). The enhancement of the thermal cleavage of the cobalt–carbon bond of cis-[R2Co(bpy)2]+ by the reactions with benzyl and allyl bromides is caused by the high reactivity of the carbanion ligand of [RCo(bpy)2]+ produced by the homolytic cleavage of the cobalt–carbon bond of cis-[R2Co(bpy)2]+, which undergoes the exchange, coupling, and cross-coupling reactions with benzyl and allyl groups of the bromides. Based on the kinetics and the activation parameters, the cobalt–carbon bond dissociation enthalpy of cis-[(PhCH2)2Co(bpy)2]+ has been estimated to be 92 kJ mol−1.
  • Yoshihiro Makide, Akihito Yokohata, Yuji Kubo, Takeshi Tominaga
    1987 Volume 60 Issue 2 Pages 571-574
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The average atmospheric concentrations of halocarbons in the mid-latitude Northern Hemisphere have been measured accurately for 7 years from 1979 to 1986. Atmospheric samples were collected in summer and winter in Hokkaido (40–45°N), and the halocarbons at 10–400 pptv (pptv=10−12 v/v) concentrations were determined with 0.5% precision. The concentrations of halocarbons with long lifetimes have been increasing steadily (CCl2F2: 18 pptv/year, CCl3F: 8–9 pptv/year, CH3CCl3: 4 pptv/year, CCl4: 2 pptv/year); those of shortlived halocarbons (CHCl=CCl2 and CCl2=CCl2) are low (<25 pptv) and show only seasonal variations.
  • Tomoji Ohishi, Kazuo Kashiwabara, Junnosuke Fujita
    1987 Volume 60 Issue 2 Pages 575-581
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    A number of new diphosphine complexes of cobalt(III), trans- and cis-[CoCl2(dmpe, dmpp, dbpe, or dpee)2]+, trans- and cis-[CoBr2(dmpe)2]+, trans- and cis-[CoCl(H2O)(dmpe)2]2+, trans-[Co(I2 or BrI)(dmpe)2]+, and [Co(CO3)(dmpp or dbpe)]+ have been prepared and characterized, where dmpe, dmpp, dbpe, and dpee denote 1,2-bis(dimethylphosphino)ethane, 1,3-bis(dimethylphosphino)propane, 1,2-bis(dibutylphosphino)ethane, and cis-1,2-bis(diphenylphosphino)ethylene, respectively. The trans isomers of the dihalogeno complexes are stable to aquation, while the cis isomers release one of the halide ions in water fairly rapidly to yield cis-[CoX(H2O)(diphosphine)2]+ which isomerizes to the trans isomer on exposure of ultraviolet light. The cis-[CoCl2(diphosphine)2]+ complexes in methanol or ethanol solution isomerize to the trans isomer, and the rates were followed spectrophotometrically in the temperature range of 39.0–65.0 °C. The rates have a first-order dependence on the complex concentration. Both the ΔH\ eweq and ΔS\ eweq values for the isomerization increase in the order diphosphine=dmpe<dmpp<dbpe<dpee. This order coincides with the increasing order in cone angle of phosphine ligands, and suggests that the difference in rates among the complexes comes from a steric factor. Absorption spectra of all the complexes have been recorded and the results compared with those of the corresponding ethylenediamine complexes.
  • Tomoji Ohishi, Kazuo Kashiwabara, Junnosuke Fujita
    1987 Volume 60 Issue 2 Pages 583-588
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Seven new cobalt(III)–phosphine complexes of the type [Co(L)(dmpe)2]n+ were prepared from trans-[Co(Cl or Br)2(dmpe)2]+, where dmpe denotes (CH3)2PCH2CH2P(CH3)2, and L is C2O42−, NH2CH2COO(gly), NH2CH(CH3)COO(ala), (C2H5)2NCS2(dtc), (NCS)2, (NCO)2, or (CN)2. Reactions of cis-[CoCl2(dmpe)2]+ with X (X=CN, NCS, and NCO) yielded only trans-[CoX2(dmpe)2]+. Qualitative stabilities of the complexes containing a bidentate ligand in aqueous solution were found to decrease in the order L=CH(CH3CO)2(acac), C2O42−, dtc>CO32−>>gly, ala>NH2CH2CH2NH2(en); the complexes containing O or S donor atoms are thermally more stable than those containing an amino donor group. The d–d absorption bands of the complexes were assigned by comparing the spectra with those of related Co(III)–phosphine and -en complexes. The IR and visible absorption spectra of the NCS and NCO complexes indicate an N coordination mode of these ambidentate ligands.
  • Hideaki Kanno, Junnosuke Fujita
    1987 Volume 60 Issue 2 Pages 589-594
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Both racemic and optically active [Cr(bpdo)3](ClO4)3·1.5H2O (bpdo=2,2′-bipyridine N,N′-dioxide) were found to crystallize in the lel2·ob(Δ(λλδ), Λ(δδλ)) isomer. The complexes isomerized spontaneously to the lel3(Δ(λλλ), Λ(δδδ)) isomer upon dissolution in water with a rapid absorption spectral change, and then racemized (Δ\ ightleftarrowsΛ) slowly. The rate constant for isomerization was 5.33×10−3 s−1 at 303.2 K, and that for racemization 1.93×10−4 s−1 at the same temperature. An intramolecular conformational inversion of the bpdo chelate ring (δ\ ightleftarrowsλ) and an intramolecular twist mechanism were proposed for the isomerization and the racemization of the complex, respectively. Neither isomerization nor racemization was observed for [Cr(en)(bpdo)2]3+ in aqueous solution.
  • Takaji Yasui, Toshie Shikiji, Norio Koine, Tomoharu Ama, Hiroshi Kawag ...
    1987 Volume 60 Issue 2 Pages 595-601
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Four geometrical isomers possible in each of [Co(edma)(dien)]2+ and [Co(edma)(mdien)]2+, where edma, dien, and mdien denote ethylenediamine-N-acetate, 3-azapentane-1,5-diamine, and 3-methyl-3-azapentane-1,5-diamine respectively, and facial isomer of [Co(edma)(NH3)3]2+ were prepared and resolved into optically active isomers by a column-chromatographic method. The structural assignments of these geometrical isomers were carried out on the basis of the absorption, 1H NMR, and 13C NMR spectral data. The absolute configurations of the optically active isomers containing facially coordinated edma were determined by 1H NMR measurements of the glycinate-ring methylene (–CHD–) of edma stereospecifically deuterated in a weak basic D2O. The relationship between the absolute configurations and the CD spectral behaviors of these isomers is also discussed.
  • Kazuo Kojima
    1987 Volume 60 Issue 2 Pages 603-607
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The visible absorption spectra of CoX2 (X=Cl, Br) in 3-methylpyridine (3-Me-py) solutions have been measured in the pressure range of 1 bar—3 kbar at room temperature, and in the temperature range of ≈5–≈76 °C at 1 bar. The equilibrium, [CoX2(3-Me-py)2] (tetrahedral)+2(3-Me-py)\ ightleftharpoons[CoX2(3-Me-py)4] (octahedral), is found to be followed over this pressure range. Higher pressures favor the octahedral species with the volume changes −18–−19 cm3 mol−1 at 1 bar. On the other hand, the above equilibrium holds fairly well at temperatures up to about 40 °C. Higher temperatures favor the tetrahedral species, the heats of reaction, being 56.7 kJ mol−1 (5.0–44.8 °C) and 58.6 kJ mol−1 (4.8–34.2 °C) for the chloro and bromo complexes, respectively. An intense and broad band appears around 400 nm at elevated temperatures especially for the bromo complex solution. This band may be assigned to a charge-transfer band occurring in a contact ion pair of solvent molecule 3-Me-py with X arising from the dissociation of the tetrahedral species [CoX2(3-Me-py)2].
  • Akira Oku, Naofumi Hori-ie, Toshiro Harada
    1987 Volume 60 Issue 2 Pages 609-612
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The utilization of 2-acyloxy-3 -phenylthiopropionitriles (2) which were prepared by the Michael addition of thiophenol to 2-acyloxyacrylonitriles (CH2=C(CN)OCOR), as a formylcarbonium ion synthon, was demonstrated by the transformation of 2 into S-phenylcysteine and 2-phenylthio enamines.
  • Yasuhisa Senda, Akihiko Ohno, Jun-ichi Ishiyama, Shin Imaizumi, Shin-i ...
    1987 Volume 60 Issue 2 Pages 613-616
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The 13C NMR spectra of diastereomeric pairs of the title compounds together with some tetrahydrofurans were examined and the chemical shifts were compared with those for the corresponding bicyclo[2.2.1]heptanes and -heptenes. The intramolecular interaction between the n-orbital of an oxygen atom and the π-orbital of an olefinic bond was found in 2-methylene-7-oxabicyclo[2.2.1]heptane. Intramolecular hydrogen bonding between the 7-oxygen and the hydroxyl group occurs in exo-7-oxabicyclo[2.2.1]heptane-2-methanol.
  • Yoshihisa Kiso, Kenji Saeki
    1987 Volume 60 Issue 2 Pages 617-620
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    In the formation of ethylene glycol from synthesis gas, amines (especially imidazole and its derivatives) enhanced the catalytic activity of a ruthenium carbonyl mixed with alkali metal halides. A rhodium carbonyl complex further promoted the activity and selectivity of a ruthenium–alkali metal halide-imidazole catalyst.
  • Tetsuro Shimo, Kenichi Somekawa, Yusuke Wakikawa, Hisako Uemura, Otohi ...
    1987 Volume 60 Issue 2 Pages 621-626
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Sensitized photoreactions of 2-pyrones with chloroethylenes gave two kinds of [2+2]cycloadducts, 2-oxabicyclo[4.2.0]oct-4-en-3-ones (4, 8) and across the C3–C4 double bond in 2-pyrone, benzene derivatives, and/or cyclobutanecarboxylic acids: Their relative yields greatly depended upon the nature of the reactants. The dehydrochlorination of the cycloadducts 4 and 8 across the C5–C6 double bonds in the pyrones with triethylamine in ethanol gave 5-ethenyl-2-pyrones, whose structures were previously incorrectly assigned as oxocinones, via a symmetry-allowed ring opening of 2-oxabicyclo[4.2.0]octa-4,6-dien-3-ones. Some 5-ethenyl-2-pyrones possessing a chlorinated ethenyl group finally affords 5-ethynyl-2-pyrones by an anti-elimination of hydrogen chloride. The X-ray crystallographic analyses of 5-ethenyl- and 5-ethynyl-2-pyrones are also described.
  • Haruo Ogawa, Toshikazu Hagiwara, Teiji Chihara, Shousuke Teratani, Kaz ...
    1987 Volume 60 Issue 2 Pages 627-629
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Alcohols and phenols adsorbed on silica gel react with diazomethane and quantitatively afford the corresponding methyl ethers. Alumina and titanium dioxide are also effective adsorbents for the reaction.
  • Kaoru Okamoto, Tadao Kondo, Toshio Goto
    1987 Volume 60 Issue 2 Pages 631-636
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The acetyl protected 2-deoxy-2,3-dehydroneuraminic acid methyl ester was functionalized by modifying its 2,3-double bond to convert it into new glycosyl donors such as 2,3-dibromo-, 2,3-epoxy-, and 2-halo-3-hydroxyneuraminic acid derivatives.
  • Kaoru Okamoto, Tadao Kondo, Toshio Goto
    1987 Volume 60 Issue 2 Pages 637-643
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Reaction of the 2β,3β-epoxyneuraminic acid derivative prepared from 2,3-dehydroneuraminic acid derivative with primary or secondary alcohol gave the corresponding glycoside(s) or ortho ester.
  • Masao Shiozaki, Hidekazu Masuko
    1987 Volume 60 Issue 2 Pages 645-648
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Optically active 4-diethoxyphosphinyl-3-(1-hydroxyethyl)-2-azetidinone (8) was synthesized from (2R,3R) N-diethoxyphosphinylmethyl-2,3-epoxybutyramide derivatives, and compound 8 was alternatively synthesized from (3R,4R)-4-acetoxy-3-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-2-azetidinone via 3-[1-(t-butyldimethylsilyloxy)ethyl] derivative.
  • Ryuzo Yoshioka, Masanori Tohyama, Osamu Ohtsuki, Shigeki Yamada, Ichir ...
    1987 Volume 60 Issue 2 Pages 649-652
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Optically active 1-phenylethanesulfonic acid was found to be an efficient resolving agent for the optical resolution and asymmetric transformation of DL-p-hydroxyphenylglycine. When DL-p-hydroxyphenylglycine was resolved by the fractional crystallization of its diastereomeric salt with (+)-1-phenylethanesulfonic acid, less soluble D-p-hydroxyphenylglycine (+)-1-phenylethanesulfonate [D-HPG·(+)-PES] was obtained in a good yield. Soluble L-HPG·(+)-PES was easily epimerized into DL-HPG·(+)-PES by heating it at 100 °C in glacial acetic acid in the presence of a small amount of salicylaldehyde. Under such epimerizing conditions, the asymmetric transformation of DL-HPG·(+)-PES was attempted by simultaneously combining the fractional crystallization of the less soluble D-HPG·(+)-PES and the epimerization of the soluble L-HPG·(+)-PES. This asymmetric transformation was achieved successfully; that is, 80% of the DL-HPG used as the starting material was converted into D-HPG.
  • Koji Chiba, Hideyuki Tagaya, Shimio Sato, Shinya Ohgi
    1987 Volume 60 Issue 2 Pages 653-659
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The effects of MoO3, Fe2O3, or SnO on the conversion and the solvent-refined coal (SRC) yield of Taiheiyo coal were small, whereas their effects on the structure of SRC were large. SRC was separated into four fractions by successive extraction in order to clarify the differences in SRC’s among the catalysts. The formation of SnO2 after the liquefaction was confirmed. It was considered that the oxygen-abstraction ability and the radicalstabilization ability of SnO prevented the retrogressive reaction of coal, SRC, and model compounds. MoO3 and Fe2O3 have a higher ability to hydrogenate and accelerate the hydrocracking of coal and coal-model compounds than does SnO, but their ability to suppress the retrogressive reaction producing heavier compounds is small.
  • Tadashi Shiraiwa, Hideya Miyazaki, Tomoki Imai, Michio Sunami, Hidemot ...
    1987 Volume 60 Issue 2 Pages 661-666
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Infrared spectrum, solubility, and ternary phase diagram of solubility indicated that 1,1,3,3-tetramethylbutylammonium salt (DL-TMB salt) of N-formyl-DL-α-phenylglycine is a conglomerate. In order to resolve DL-TMB salt efficiently, crystallization of D- and L-TMB salts was examined by free energy of critical nucleation in supersaturated solutions. Successive preferential crystallization of DL-TMB salt was experimented at 10 °C for racemic solution in ethanol with the degree of supersaturation of 130%, and D- and L-α-phenylglycine with 100% optical purity were obtained from pure D- and L-TMB salts.
  • Xue-Ping Gu, Isao Ikeda, Mitsuo Okahara
    1987 Volume 60 Issue 2 Pages 667-672
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    A series of trans-3-chloroallyl ethers and trans-3-thioallyl ethers were stereoselectively synthesized in one step by the reaction of 1-chloro-2,3-epoxypropane or 2,3-epoxypropyl sulfides with alkyl chlorides in the presence of solid sodium hydroxide and quaternary ammonium salt as a phase-transfer catalyst. Phase-transfer catalytic hydroxide ion-initiation followed by stereoselective isomerization of the epoxide ring through β-elimination is postulated as the important part of the reaction pathway.
  • Mikio Nakamura, Michinori Oki
    1987 Volume 60 Issue 2 Pages 673-682
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The pKa′ values of the trifluoroacetate salts of the title compounds were determined in THF–water (3:2) solution at 25 °C by potentiometric titration: in every compound examined, basicity of the ap rotamer was higher than that of the sp rotamer. Differences in pKa′ values (ΔpKa) between the rotamers are in the range of 0.55 to 1.14 pKa units, depending upon the substituents on the nitrogen atom. The ΔpKa values in chloroform-d solution at 80.1 °C determined by taking advantage of the equilibrium constants of the salts and the free amines were larger than those obtained in aqueous THF solutions and were nearly independent of the substituents. The results were explained in terms of the intramolecular NH-π interactions in the ap salts, which are not possible in the sp. 1H and 13C NMR spectral data were in conformity with the presence of the interactions. Examination of the population ratios in various solvents revealed that sp conformers of the free amines are generally favored over the ap in polar, proton-accepting solvents, but the reverse is true for the trifluoroacetate salts. As the results, ΔpKa values are large in toluene and chloroform but are rather small in tetrahydrofuran, acetonitrile, and nitromethane. Possible causes for the differences including solvation and hydrogen bond formation are discussed.
  • Nobuhiro Kanomata, Tadashi Kobayashi, Takashi Uetake, Shuji Okada, Mak ...
    1987 Volume 60 Issue 2 Pages 683-687
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The 1,3-Dipolar cycloaddition of phenyl azide with 1,3,5-trimethyl-6-methylenetricyclo[3.2.1.02,7]oct-3-en-8-one occurred onto the endocyclic double bond to give the exo- and endo-adducts (7 and 8) in a similar ratio. Upon photoirradiation, 7 and 8 eliminated a nitrogen molecule to give 3,5-exo- and 3,5-endo-1,3,6-trimethyl-7-methylene-4-azatetracyclo[4.2.1.0.2,803,5]nona-9-ones (9 and 10) in good yields. The 1,3-Dipolar cycloaddition of 2,4,6-trimethylbenzonitrile oxide with 9 and 10 occurred onto the exocyclic double bond to give two stereoisomers in each case. The stereoselectivity of the reactions is discussed on the basis of the stereoelectronic factor of the aziridine ring. The thermal reaction of 9 and 10 as well as photoirradiation of 9 caused a simple C–N bond cleavage of the aziridine ring. However, photoirradiation of 10 or its dimethyl analogue caused an unusual skeletal rearrangement resulting in the formation of 9-methylene-6-phenyl-6-azatricyclo[3.3.1.02,8]nona-3-en-7-one ring system. Mechanistic pathways of the rearrangement were postulated.
  • Sadao Tsuboi, Hirohumi Fukumoto, Hiroshi Wada, Akira Takeda, Keiichi F ...
    1987 Volume 60 Issue 2 Pages 689-696
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Reactions of glutaric anhydride and methyl- or phenyl-substituted ones with (α-alkoxycarbonylethylidene)triphenylphosphorane (2a, ethoxy; 2b, t-butoxy) gave the corresponding 6-alkoxycarbonyl-5-hepten-5-olides (3) and 6-alkoxycarbonyl-4-hepten-5-olides in good yields. The reaction proceeded highly stereoselectively to give (E)-3. The stereochemistry of 3 was determined by an X-ray crystallographic analysis. The reaction of adipic anhydride with 2a afforded 7-ethoxycarbonyl-5-octen-6-olide, 7-ethoxycarbonyl-5,6-octadienoic acid, and (4E, 6E)-7-ethoxycarbonyl-4,6-octadienoic acid. A treatment of nonanedioic anhydride with 2a gave 10-ethoxycarbonyl-8,9-undecadienoic acid, (7E,9E)-10-ethoxycarbonyl-7,9-undecadienoic acid, and diethyl 2-methyl-2,4-undecadienedioate in low yields.
  • Hisakazu Mihara, Tatsuhiko Kanmera, Mutsuo Yoshida, Sannamu Lee, Haruh ...
    1987 Volume 60 Issue 2 Pages 697-706
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Twelve peptides having 4 to 6 basic amino acid residues in the hydrophobic amino acid sequence were designed and synthesized by the solution method to find peptides with potential activity against Gram-positive and -negative bacteria. CD study of the peptides demonstrated that they formed α-helical structures in the presence of phospholipid liposomes consequently to have amphiphilic property along the axis of helix. The peptides also induced the leakage of the dye carboxyfluorescein from phospholipid vesicles, indicating that the peptides possess the ability to perturb the membrane structure. These peptides showed antibacterial activity against Gram-positive bacteria, and some of them were also active against Gram-negative bacteria. Relationships between the structure and antibacterial activity of the synthetic peptides were discussed.
  • Hajime Nagano, Yukari Masunaga, Yukiko Matsuo, Michio Shiota
    1987 Volume 60 Issue 2 Pages 707-711
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    α-Santonin was converted to 2,6-dimethyl-6-(8-methyl-4-methylene-7-nonenyl)-2-cyclohexene-1-methanols (1a and 1b). Both spectral data of 1a and 1b were found to be different from those reported for magydar-2,10(20),13-trien-17-ol, a diterpene isolated from Magydaris panacifolia (Vahl) Lange. This indicates that the structure of the natural diterpene should be revised; the structure was later revised to t-6-hydroxymethyl-1, t-3-dimethyl-t-2-(3-methyl-2-butenyl)-3-(4-methyl-3-pentenyl)-r-1-cyclohexanol.
  • Yoshihiko Kobayashi, Tsutomu Tsuchiya, Sumio Umezawa, Toshio Yoneta, S ...
    1987 Volume 60 Issue 2 Pages 713-720
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    2′,3′-Dideoxykanamycin A has been prepared via two ways. 2″-O-Acetyl-4″,6″-O-benzylidene-6′-N,4′-O-carbonyl-1,3,3″-tri-N-tosylkanamycin A was converted to a 2′,3′-unsaturated compound by a modified Tipson and Cohen method. Hydrogenation followed by deblocking gave 2′,3′-dideoxykanamycin A (12). Another route for 12 was through 2′,3′-anhydro-4′,2″,4″,6″-tetra-O-benzoyl-2′-epi-1,3,6′,3″-tetrakis(N-ethoxycarbonyl)kanamycin A (16). Epoxide-ring opening of 16 with hydrogen iodide gave the 3′,2′-iodohydrin, which, after 2′-O-mesylation, led to the 2′,3′-unsaturated compound (19). Deblocking and hydrogenation of 19 gave 12. 2′,3′-Dideoxykanamycin A thus synthesized was led to 2′,3′-dideoxyamikacin and other related compounds by amino protection of 12 other than the 1-amino group by zinc acetate–ethyl trifluoroacetate method followed by 1-N-acyl or 1-urethane formation with appropriate reagents. Their antibacterial activities were described.
  • Toshio Sugita, Hiroshi Ito, Akihiko Nakajima, Motoshi Sunami, Atsushi ...
    1987 Volume 60 Issue 2 Pages 721-725
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Chlorination of acyclic β-diketones with triphenylphosphine–carbon tetrachloride and the other chlorinating reagents predominantly afforded β-chloro-β,γ-unsaturated ketones except the cases of the terminal alkyl group of the diketones was methyl or t-butyl. In these reactions, the isomerization of the β-chloro-α,β-unsaturated ketones to the β,γ-unsaturated isomers was involved; the isomerization was achieved by triphenylphosphine–carbon tetrachloride as well as by some acid catalysts.
  • Yoichi Taguchi, Koshin Yanagiya, Isao Shibuya, Yasuo Suhara
    1987 Volume 60 Issue 2 Pages 727-730
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The reaction of 2,2-dimethylthiirane with carbon disulfide in the presence of triethylamine was accelerated under high pressure to give 4,4-dimethyl-1,3-dithiolane-2-thione nearly quantitatively. The activation volume of this reaction at 40 °C was estimated to be −41 ml mol−1. The rate of the reaction was proportional to the amount of triethylamine when a limited amount of triethylamine was used. The reaction of 2-methylthiirane, 2-hexylthiirane, 1,2-epithiocyclohexane, and 2-phenylthiirane with carbon disulfide gave the corresponding 1,3-dithiolane-2-thione derivatives in good yields. 2-Chloromethylthiirane was less reactive to carbon disulfide than other thiiranes under high pressure. Tertiary amines such as N,N-dimethylethylamine, pyridine, and N-methylmorpholine were good catalysts of the reaction.
  • Seiichi Yogi, Kozo Hokama, Sadamori Takayoshi, Otohiko Tsuge
    1987 Volume 60 Issue 2 Pages 731-735
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Nucleophilic substitution of 4,7-dichloro-3,8-diphenyl-1,2-diazocine with succinimide, phthalimide, N-methyl-p-toluenesulfonamide, and o-benzosulfimide, in the presence of silver oxide, gave the corresponding 4-mono(imido)- and 4,7-di(imido)-1,2-diazocines. 4-Acetoxy-7-phthalimido- and 4-phenylthio-7-phthalimido-1,2-diazocine were also prepared. Thermolysis of the mono(imido)-1,2-diazocines in xylene under reflux afforded the corresponding di(imido)-1,2-diazocine and/or five pyridine derivatives, whose relative yields depended upon the nature of imido substitutents in the diazocines. However, 4,7-di(imido)-1,2-diazocines did not decompose in xylene under reflux. Thermolysis of 4,7-bis(phthalimido)-1,2-diazocine at 300–310 °C gave 3,6-bis(phthalimido)-2-phenylpyridine with the extrusion of benzonitrile. In the thermolysis of the acetoxy(230–240 °C) or phenylthio-substituted 1,2-diazocine (240–260 °C), 6-acetoxy- and 6-benzoyl-3-phthalimido-2-phenylpyridine, or 6(and 3)-phenylthio-3(and 6)-phthalimido-2-phenylpyridines were isolated together with benzonitrile, respectively. The feature of thermolysis was also discussed.
  • Hidenori Chikashita, Shuichi Nishida, Makoto Miyazaki, Yasuhiro Morita ...
    1987 Volume 60 Issue 2 Pages 737-746
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    2-Phenylbenzimidazoline (PBI) as a mild, selective, and convenient reducing agent was efficiently generated in situ from o-phenylenediamine and benzaldehyde in alcohols. A generally applicable method for the selective reduction of carbon–carbon double bonds of a variety of electron-deficient olefins with an alcoholic solution of PBI is described. The reduction of α,β-unsaturated ketones to the corresponding saturated ketones could also be accomplished (but, less effectively) with PBI with the aid of a Lewis-acid catalyst. 1-Methyl-2-(o-nitrophenyl)benzimidazoline prepared and isolated by the reaction of o-nitrobenzaldehyde with N-methyl-o-phenylenediamine reduced benzylidenemalononitrile to give benzylmalononitrile and 1-methyl-2-(o-nitrophenyl)benzimidazole in high yields. This shows the validity of PBI to be the actual reducing species in the present reduction system. From a mechanistic study, the present reductions could be interpreted in terms of a mechanism involving a synchronous transport of a pair of hydrogens or a sequential transfer of a hydride and a proton from PBI to the olefins.
  • Katsumi Kuwabara, Shoichi Ichikawa, Kohzo Sugiyama
    1987 Volume 60 Issue 2 Pages 747-752
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    Electrochromic display (ECD) was investigated using WO3 as the electrochromic material and metals as the counter electrode. WO3 was vacuum-evaporated on a glass substrate coated with indium tin oxide. A film of solid electrolyte, Sn(HPO4)2·H2O, was prepared by means of the spray method on the thin film of WO3. ECDs with metal electrodes were examined from the points of view of the change in optical density, the current-wave forms, and the response speeds in coloring and bleaching processes. ECD cells with noble metals indicated comparatively high optical density changes on coloration at a constant-voltage operation. The cell with Ag showed a high coloration speed compared with the cells containing graphite and other metals.
  • Kiyokazu Imai, Yasuyuki Tezuka, Tomoo Shiomi, Matsunori Takada
    1987 Volume 60 Issue 2 Pages 753-757
    Published: 1987
    Released: June 27, 2006
    JOURNALS FREE ACCESS
    The Michael type addition reaction of cellulose with a series of vinyl sulfoxides, namely methyl vinyl sulfoxide, ethyl vinyl sulfoxide, t-butyl vinyl sulfoxide, and phenyl vinyl sulfoxide, was performed with NaOH as a catalyst to produce 2-(alkyl- or arylsulfinyl)ethyl cellulose derivatives. The high permselectivity of sulfur dioxide against nitrogen and oxygen was achieved through these sulfoxide modified cellulose membranes.
feedback
Top