bluuebunny/crossref_metadata_2025 huggingface dataset:
Volumetric Determination of the Iodide Ion with Mercury(II) Ethylenediaminetetraacetate Using Mercury(II)-Methyl-thymolblue as an Indicator
Authors: Nomura Toshiaki
Published: July 2006

After 5 ml portions of 1×10−4  m methylthymolblue (MTB or H2Me4−) and mercury(II) nitrate solutions had been added to an iodide sample solution adjusted to pH 7.3–8.8, it was diluted to about 50 ml with water. This solution was titrated with a 1×10−2  m standard mercury(II) ethylenediaminetetraacetate (Hg-EDTA or HgY2−) solution until it turned blue from greenish yellow. The iodide-ion content was calculated by applying the volume of the standard Hg-EDTA solution on the calibration curve determined with solutions of known iodide-ion contents. The iodide ion reacts with HgY2− and with greenish-yellow HgMe4− to form colorless [HgY(I)]3− and blue [HgMe(I)]5− complexes respectively. The [HgMe(I)]5− complex reacts subsequently with the iodide ion to form mercury(II) iodide and greenish-yellow H2Me4−. It has been found that, except when an excess amount of the iodide ion existed, the [HgMe(I)]5− complex is the most stable among these mixed ligand complexes and mercury(II) iodide. Therefore, the iodide ion can be titrated directly with a Hg-EDTA solution by using HgMe4− as an indicator according to the following equation:

HgI2+H2Me4−+HgY2−→[HgMe(I)]5−+[HgY(I)]3−+2H+
Spectrophotometric Studies of Ethyl Xanthate Complexes in Aqueous Solutions
Authors: Nanjo Michio , Yamasaki Taro
Published: July 2006

The stability constants of ethyl xanthate complexes of cadmium(II), zinc(II), nickel(II), and cobalt(II) were determined spectrophotometrically in aqueous solutions. Complexes with the 1 : 1 composition, M(EX)+, were found in all cases; the stability constants of these metal complexes were calculated to be 1.2×104, 5.2×10, 4.4×10, and 1.1×10 for Cd(EX)+, Zn(EX)+, Ni(EX)+, and Co(EX)+ respectively at an ionic strength of 1.0 and at 25°C. These values were then compared with the stability constants of other metal complexes.
The Synergistic Effect in Solvent Extraction. The Effect of the Chelating Ligands on the Stability Constant of Lutetium β-Diketonate Adducts with TOPO
Authors: Honjyo Takaharu
Published: July 2006

The steric effect and the inductive effect of the functional groups of β-diketones on the adduct formation between lutetium chelates and TOPO in benzene was studied by using various β-diketones with aliphatic groups (acetylacetone, dipropionylmethane, pivaroylacetone, diisobutyryl-methane and dipivaroylmethane), aromatic groups (benzoylacetone, naphthoylacetone and dibenzoylmethane) and fluoromethyl groups (trifluoroacetylacetone, furoyltrifluoroacetone, thenovltrifluoroacetone, benzoyltrifluoroacetone and hexafluoroacetylacetone). The effect of the temperature on the adduct formation was then estimated. These results may be summarized as follows: (1) The stability of the adduct increases, and the larger synergism appears, as aliphatic groups, aromatic groups, and fluoromethyl groups are successively substituted for the functional groups of β-diketones. This effect may be due to the electron-withdrawing effect of the fluoromethyl group and the conjugation effect (with a metal chelate ring) of the phenyl group. (2) The adducts contain one molecule of TOPO per metal chelate except for the HFA adduct, which contains two molecules of TOPO. The steric hindrance of the terminal groups is hardly recognizable. (3) The extraction constant of the chelates increases, while the stability of the adducts decreases, with a rise in the temperature. The apparent enthalpy change (−ΔH kcal/mol) upon the adduct formation increases in the order: DPM (5.5)<BzA(5.9)<BFA(8.6) chelates.
A Study of the Decomposition Reaction of Cumene Hydroperoxide in the Presence of Triphenylsulfonium Chloride
Authors: Ohkubo Katsutoshi , Yamabe Tokio , Fukui Kenichi
Published: July 2006

The homogeneous decomposition reaction of cumene hydroperoxide in cumene was studied by the use of triphenylsulfonium chloride over a low-temperature range (30–80°C). The hydroperoxide was decomposed remarkably in the presence of the sulfonium catalyst, whereas in the absence of the catalyst it was decomposed only a little. Among the homolytic decomposition products, acetophenone and dicumyl peroxide were found to be the main products, while α-cumyl alcohol was formed in only a small amount. Moreover, methyl alcohol was found in appreciable amounts. Traces of heterolytic reaction products, such as phenol and acetone, were also detected. After discussing the reaction mechanism and the nature of catalytic action, it is concluded that the partially-occupied d orbital of the sulfonium cation may play a role in breaking the oxygen-oxygen bond of the hydroperoxide homolytically. The counter chloride anion seems to take part in the heterolytic reaction to some extent.
Electronic Structures of Unsaturated Molecules Containing Hetero-atoms, — Configuration Interaction Treatment Including Doubly Excited Configurations
Authors: Hirota Fumihiko , Nagakura Saburo
Published: July 2006

The π-electron structures of several unsaturated molecules containing hetero-atoms were studied by SCFMO-CI scheme employing the Pariser-Parr-Pople method, special attention being paid to the effect of doubly excited configurations upon calculated transition energies, transition moments and π-electron distributions in the ground and lower excited states. The transition energies and oscillator strengths calculated for pyridine, phenol, aniline, pyrrole and furan were compared with their experimental values. Consequently, the inclusion of doubly excited configurations was found to improve the coincidence between the theoretical and observed values and to remove some difficulties in the application of the Pariser-Parr-Pople method to molecules containing hetero-atoms. One-center integrals WP and γPP for hetero-atoms were taken as parameters in the calculations of phenol and aniline. Their fittest values were determined reasonably to be WN=−24.71, Wo=−30.08, γNN=13.75, and γOO=16.78 eV.
Imidazole Catalyses in Aqueous Systems. III. Formation of the Catalyst-Substrate Complex in the Hydrolysis of a Phenyl Ester Catalyzed by a Naphthylimidazole Derivative
Authors: Kunitake Toyoki , Shinkai Seiji , Aso Chuji
Published: July 2006

Catalytic hydrolysis of p-acetoxybenzoic acid by 1-[4(5)-imidazolyl]-4-aminomethylnaphthalene was carried out at 30°C in aqueous systems using a pH-stat. The catalytic rate leveled off at high substrate concentrations and increased remarkably at high pH. The data indicated that both the neutral catalytic species (AmIm) and the monoprotonated catalytic species (Am+Im) acted as enzyme-like catalysts, the catalytic rate conforming to the Michaelis-Menten kinetics, although their catalytic efficiencies were quite different: Km (dissociation constant of the catalyst-substrate complex)=0.011m and k3 (pseudo-intramolecular rate constant of the product-formation)=0.19 min−1 for AmIm, and Km=0.041m and k3=0.036 min−1 for Am+Im. The binding function was attributed to hydrophobic interaction, on the ground that Km was smaller for AmIm than for Am+Im and that an increase in the ionic strength of the medium caused rate enhancement. The hydrolysate showed an inhibitory action. The wide variation of the catalytic efficiency between AmIm and Am+Im may be related to the structural difference of the Michaelis complexes. 1-Aminomethylnaphthalene similarly catalyzed the hydrolysis and showed a substrate binding phenomenon, though the saturation phenomenon was much less pronounced as compared with the imidazole catalyst.
Formation of 4-Hydroxycarbostyrils in the Reaction of Carbon Suboxide with Aromatic Amines
Authors: Omori Akira , Sonoda Noboru , Tsutsumi Shigeru
Published: July 2006

The reactions of carbon suboxide with aromatic amines were found to give various 4-hydroxycarbostyril derivatives. The reaction between aniline and carbon suboxide usually gives malonanilide. However, it was found that the reaction of aniline with carbon suboxide in ether in the presence of aluminum chloride produced phenylcarbamoylacetic acid in a good yield and that cyclization to 4-hydroxycarbostyril occurred when the solvent was replaced by benzene before the decomposition of the reaction mixture with water. The solvent effect on the formation of 4-hydroxycarbostyrils and the possible reaction mechanism were discussed.
Oxidation by Transition Metal Complexes. I. Oxidation of Styrene and Triphenylphosphine Catalyzed by O2-Ir Complex
Authors: Takao Kiyotomi , Fujiwara Yuzo , Imanaka Toshinobu , Teranishi Shiichiro
Published: July 2006

In order to investigate the oxidation reaction which is catalyzed by transition metal complexes in a homogeneous system under mild conditions, the oxidation reactions of styrene and triphenylphosphine catalyzed by various iridium complexes have been studied. The Vaska complex (IrX(CO)(PPh3)2) and the biphosphine chelate complex have been found to be effective as oxidation catalyst. It was found that the SnCl3 ligand which has a strong trans effect promotes the oxidation of styrene. For the sake of comparison with the iridium compounds, oxidation with palladium salts was also studied.
The Preparation and Reaction of Disubstituted Aminophosphonium Bromide. Reaction of Triphenylphosphine Dibromide with Secondary Amines
Authors: Fukui Kiyoshi , Sudo Rokuro
Published: July 2006

Disubstituted aminotriphenylphosphonium bromides were obtained in excellent yields from the reaction of triphenylphosphine dibromide and the secondary amines using simple procedures. This method has an advantage in the preparation of cyclic aminophosphonium salts, such as those of morpholine or piperidine. The treatment of the disubstituted aminophosphonium salt with bases resulted in dehydrohalogenation, followed by a Hofmann-like decomposition, and gave imine and triphenylphosphine.
Studies of Peptide Antibiotics. XVI. Analogs of Gramicidin S Containing β-Alanine in Place of l-Proline
Authors: Matsuura Shuji , Waki Michinori , Makisumi Satoru , Izumiya Nobuo
Published: July 2006

5,5′-β-alanine-gramicidin S having a larger ring size by two methylene groups than that of gramicidin S was synthesized to investigate the contribution of the ring size of gramicidin S to antibacterial activity. Cyclization of a protected linear decapeptide active ester in pyridine gave the protected 5,5′-β-alanine-gramicidin S in a good yield. The product obtained after the cyclization of a protected linear pentapeptide active ester consisted of the protected 5-β-alanine-cyclosemi and 5,5′-β-alanine-gramicidin S. Pure compounds were obtained by column chromatographic separation of Sephadex LH-20. Hydrogenolysis of these protected cyclic peptides in the presence of hydrogen chloride afforded crystalline hydrochlorides of cyclic deca- and pentapeptide. These hydrochlorides exhibited no antibacterial activity against any of the microorganisms tested. Optical rotatory dispersion measurements of these peptides were also carried out.
Studies of Peptide Antibiotics. XVII. Analogs of Gramicidin S Containing Glycine or Alanine in Place of Leucine
Authors: Abe Okitoshi , Izumiya Nobuo
Published: July 2006

In order to investigate the contribution to antibacterial activity of the leucine residues at 3- and 3′-position in gramicidin S, 3,3′-glycine- and 3,3′-l-alanine-gramicidin S (XII-G and XII-A) were prepared and tested for antibacterial properties. A crude product obtained after cyclization of a linear pentapeptide active ester consisted of a protected monomer and a dimer. The pure protected dimer was obtained by a Sephadex LH-20 column from the crude product. Hydrogenolysis of the pure protected dimer afforded the crystalline hydrochloride of XII-G or XII-A. It was found that XII-G showed no activity in any of the microorganisms tested, whereas XII-A exhibited substantial activity though weaker than that of gramicidin S.
Studies on the Formation of Deoxy Sugars by Detosyloxylation with Lithium Aluminum Hydride
Authors: Umezawa Sumio , Tsuchiya Tsutomu , Hineno Hirokuni
Published: July 2006

The reduction of a number of tosylated, mesylated, sometimes further-benzoylated derivatives of methyl 4,6-O-benzylidene-α-d-glucopyranoside (I) with lithium aluminum hydride in tetra-hydrofuran has been investigated; it has thus been found that methyl 4,6-O-benzylidene-2,3-di-O-tosyl-α-d-glucopyranoside (II) gave methyl 4,6-O-benzylidene-3-deoxy-α-d-ribo-hexopyranoside (III, major), methyl 4,6-O-benzylidene-2-deoxy-α-d-arabino-hexopyranoside (IV, minor), and methyl 4,6-O-benzylidene-2-deoxy-α-d-ribo-hexopyranoside (V, minor) as deoxy derivatives through two kinds of monotosyl derivatives (VIII and X), and that methyl 2-O-benzoyl-4,6-O-benzylidene-3-O-tosyl-ribo-d-glucopyranoside (VII) and methyl 3-O-benzoyl-4,6-O-benzylidene-2-O-tosyl-α-d-glucopyranoside (IX) gave VIII and X respectively, as intermediates. 2-O-Methyl-3-O-tosyl (XI) and 2-deoxy-3-O-tosyl derivatives (XIII) gave detosylated derivatives, (XII) and (IV) respectively. These and other results suggest, for detosyloxylation, a mechanism through the formation of an alkoxy-aluminum hydride.
Kinetics of Alkaline Hydrolysis of Esters. III. Acyl Acetals
Authors: Sharma R C , Sharma M M
Published: July 2006

The kinetics of the alkaline hydrolysis of some acyl acetals (liquid and solid) was studied in 90 parts (wt/wt) aqueous ethanol medium. Steric and inductive effects were found to play an important role. A straight line relationship was observed between the rate constants for the alkaline hydrolysis of benzylidene-, and m- and p-nitrobenzylidene diacetates and Hammett’s substitution constant, σ. In the case of n-butylidene and benzylidene diacetates the theory of mass transfer accompanied by fast pseudo first-order reaction was employed for the determination of rate constants in an aqueous medium.
Studies of the Chemiluminescence of Several Xanthene Dyes. V. Blue Emission from an Excited State of a Reaction Product
Authors: Kamiya Isao , Kato Sadao
Published: July 2006

We have found that the chemiluminescence emission of several xanthene dyes with hydrogen peroxide is comprised of two emission components; one is a greenish-yellow emission whose spectral distribution is similar to that of the fluorescence of the dye, and the other is a blue emission similar to the fluorescence band which appears during the course of the reaction. Summarizing the results, we can conclude that the chemical formation of an excited species from the oxidation of a dye, and an energy-transfer process from the species to an unoxidized dye, are likely to be the mechanism for the luminescent reaction. Certain dyes, uranin, eosin Y, eosin R, erythrosin B, 2′,7′-dichlorofluorescein, mercurochrome, rhodamine B, rhodamine 6G, and rhodamine S, showed similar characteristic chemiluminescence emissions, whereas phloxine, rose bengale, 4-nitrofluorescein, 4,5,6,7-tetrachlorofluorescein, sulfonfluorescein, and pyronine G did not chemiluminesce under comparable conditions.
The Anodic Oxidation of a Propionate-Propionic Acid Solution in the Presence of Several Organic Compounds
Authors: Kunugi Akira , Shimizu Toshiyuki , Nagaura Shigeo
Published: July 2006

The anodic oxidation of the propionate anion in aqueous solutions of propionic acid at a platinum electrode has been studied in the presence of several organic compounds in order to demonstrate the formation of both propionoxy and ethyl radicals as the reaction intermediates. One of the following organic compounds was added to each solution: two vinyl monomers (acrylic acid and acrylamide), two alkylbenzenes (toluene and cumene), and two aliphatic alcohols (methanol and isopropanol). The electrooxidation of sodium propionate in the presence of acrylamide resulted in polymerization, which was confirmed to be initiated by the ethyl radical. Acrylic acid, unlike acrylamide, gave no polymers. In this case, both the current efficiency for the formation of carbon dioxide and the yield ratio of ethylene to carbon dioxide were always less than those observed in the absence of acrylic acid. While the addition of alcohols gave no definite results, the addition of toluene or cumene resulted in an appreciable decrease in the yield ratio of ethylene to carbon dioxide, but affecting neither the ratio of ethane to carbon dioxide nor the current efficiency for the carbon-dioxide evolution. These results indicate that the anodic oxidation of the propionate anion proceeds through the consecutive formation of propionoxy and ethyl radicals as the reaction intermediates.
The Crystal Structure of 1-Ethyl-2-methylquinolinium Iodide, [(C12H14N)+·I−]
Authors: Sakanoue Seiki , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami , Kakudo Masao
Published: July 2006

The crystal structure of an organic charge-transfer complex, 1-ethyl-2-methylquinolinium iodide, [(C12H14N)+·I−], has been determined by means of three-dimensional X-ray data (MoKα). The crystals are monoclinic, space group P21/c, and have four formula units in a unit cell with the dimensions of a=7.187±0.002, b=15.914±0.002, c=10.331±0.002 Å, and β=94.67±0.01°. The structure is built up from an iodide anion and a planar 1-ethyl-2-methylquinolinium cation, which lie roughly on a plane. The cations are stacked approximately parallel to the a-plane, forming an endless column along the a axis; the interplanar spacings of these cations are alternately 3.4 and 3.6 Å. The iodide anions are located in the spaces between these columns and the ethyl groups of the cations. The closest distance between an iodide anion and the carbon atoms of a 1-ethyl-2-methylquinolinium ring is 3.93 Å.
Lattice Vibrations of Potassium Oxalate Monohydrate and the Bound State of Water of Crystallization
Authors: Fukushima Kunio
Published: July 2006

A normal coordinate treatment of the potassium oxalate monohydrate crystal as a whole was carried out. On the basis of the results of the calculation, the nature of the lattice vibrations and the bound state of the water of crystallization were discussed.
The Radiolysis and Photolysis of Methanolic Solutions of Eosin. II. The Photo-Debromination of Eosin in an Alkaline Solution
Authors: Kimura Kazuie , Miwa Takuji , Imamura Masashi
Published: July 2006

Semireduced eosin was found to undergo photo-debromination and was identified with a precursor in the photo-debromination of eosin in alkaline methanolic solutions. Semireduced eosin was prepared by the γ-irradiation of an eosin solution. The photolysis of semireduced eosin was investigated by the use of continuous and flash light. From the absorption spectral change and a study of the decay, the mechanism of the photo-debromination was proposed. The debromination process of the photo-excited semireduced eosin was explained satisfactorily by assuming the transient formation of the debrominated-eosin σ-radical as an intermediate. In addition, we found an electron-transfer reaction from semireduced debrominated eosin to eosin, which results in the formation of semireduced eosin and debrominated eosin in the dark. A general conclusion as to the photo-dehalogenation of xanthene dyes is also given.
The Chemical Behavior of Low Valence Sulfur Compounds. II. Thin-layer Chromatographic Separation and Photometric Determination of Low Valence Sulfur Compounds
Authors: Naito Kunishige , Takei Shinsuke , Okabe Taijiro
Published: July 2006

The quantitative determination of some low valence sulfur compounds, especially low polythionates, which appeared as intermediate products in the oxidation of elemental sulfur with compressed oxygen in aqueous ammonia was investigated by means of thin-layer chromatography and colorimetry with methylene blue to establish the mechanism of the oxidation of elemental sulfur. Thiosulfate and some low polythionates could be resolved clearly by thin-layer chromatography using silica gel as an absorbent. A suitable solvent for the development was a mixed solution of ethyl alcohol, n-butyl alcohol, aqueous ammonia, ammonium acetate and distilled water. The amount of sulfur in the developed spot of the thin-layer chromatogram was determined photometrically with precision of 10 to 20% using methylene blue as a color reagent. Sulfate, sulfite and thiosulfate could not be developed effectively by this method.
Activity Measurements in Orthosilicate and Metasilicate Solid Solutions. II. MgSiO3-FeSiO3 at 1154, 1204, and 1250°C
Authors: Kitayama Kenzo
Published: July 2006

The activity-composition relation in the pyroxene solid solution, MgSiO3–FeSiO3, is determined by the quenching method in the atmosphere of a gas mixture of CO2 and H2 at 1154, 1204, and 1250°C. A non-ideality is found in the solution at these temperatures, and it increases with a decrease in the temperature. The standard free energy values of the formation of ferrosilite, FeSiO3, from metallic iron, silica, and oxygen are −42.5±0.3, −41.7±0.2, and −41.3±0.2 kcal per mole of FeSiO3 at 1154, 1204, and 1250°C respectively. Using the data by Darken and Gurry, the standard free energies of the formation of ferrosilite from wüstite and silica are obtained as −1.8±0.3, −1.5±0.2, and −1.8±0.2 kcal per mole of FeSiO3 at 1154, 1204, 1250°C respectively.
The Kinetics of the Aminolysis of Phenyl Phenoxyacetates with Benzylamine in Dioxane
Authors: Furuya Yoshiaki , Itoho Kazuo
Published: July 2006

The rates of the reactions of p- and m-substituted phenyl phenoxyacetates with benzylamine in dioxane, thus forming N-benzylphenoxyacetamide and the corresponding phenols, were followed by the non-aqueous titration of benzylamine. The reaction satisfied the following general equation:

ν={k_2’+k_3’[Amine]}[Amine][Ester]+{k_3”+k_4[Amine]}[Amine][Ester]^2.

The reaction was a neucleophilic substitution, and the Hammett plots gave straight lines with positive ρ values. A marked enhancement in the conductivity of the reaction mixtures in 50% dioxane was observed, it increasing with the reaction time. A probable mechanism was presented which involves an ion pair of the quaternary ammonium salt type somewhat similar to that discussed in a previous paper (Y. Furuya, S. Goto, K. Itoho, I. Urasaki and A. Morita, Tetrahedron, 24, 2367 (1968)).
Studies on Interactions of Isocyanides with Transition Metal Complexes. IV. Dicarbonyl(isocyanide)-π-cyclopentadienylacylmolybdenum
Authors: Yamamoto Yasuhiro , Yamazaki Hiroshi
Published: July 2006

Isocyanides were treated with π-C5H5Mo(CO)3R (R=CH3, CH2Ph) in benzene at room temperature to give π-C5H5Mo (CO)2 (isocyanide)COR (A), which exist as a trans-isomer in the solid state and as a mixture of trans- and cis-isomers in solutions, based on the NMR spectra. The structures of the compounds (A) are discussed on the basis of the spectroscopic studies. Studies on trans to cis isomerization were also carried out kinetically.
Umwandlung von Aldehyden in 2-monosubstituierte Aziridine. Reduktion von α-Chlor, Brom- und Sulfonyloxynitilen mit Lithiumaluminiumhydrid
Authors: Ichimura Kunihiro , Ohta Masaki
Published: July 2006

The reductive cyclization of α-chloro, bromo- and sulfonyloxycarbonitriles are described. α-Chlorocarbonitriles were reduced by lithium aluminum hydride to afford aziridines in sufficient yields. The Walden inversion was found to take place in the cource of the reductive cyclization of S-α-chloroisocapronitrile. We have found the two-step conversion of aldehydes to 2-mono-substituted aziridines which consists of treating aldehydes with benzenesulfonyl chloride and alkali cyanide to form α-benzenesulfonyloxycarbonitriles which are reduced by lithium aluminum hydride to the corresponding aziridines. The reduction of α-bromocarbonitriles with the hydride yielded prim. amines together with the aziridines.
Laser-induced Chemical Reactions. III. The Decomposition of Metal Salts of Carboxylic Acid and Selective Decomposition
Authors: Taki Ko , Kim Pil Hyon , Namba Susumu
Published: July 2006

Various copper metal salts of organic acid were decomposed by laser heating and conventional heating methods. The product distributions were reasonably explained in terms of the expected reaction of the decarboxylated intermediates. Generally the yield percentage of products is higher in laser decomposition than in thermal decomposition. However, in maleate and fumarate the product distribution is quite different in thermal and laser decompositions. The main product is ethylene in the thermal decomposition, but acetylene in the laser decomposition. This difference may be the result of the heating rate. Since rapid heating and quenching are characteristic of laser heating, the formation of acetylene may be brought about by the simultaneous decarboxylation of two carboxyl groups, while the formation of ethylene may be brought about by successive decarboxylation. Selective decomposition by laser heating will also be discussed in binary systems, such as maleate and ethylene.
Substituent Effects on the NMR Chemical Shifts of Aromatic Side Chain Protons. I. The Effects of meta-Substituents
Authors: Yamada Hiroaki , Tsuno Yuho , Yukawa Yasuhide
Published: July 2006

The Hammett type treatment of the chemical shift of substituted aromatic side chain protons has not always been successful. The failure might be ascribed to the neglect of magnetic longrange effects. When the corrections were made both for the ring current diminution due to the contribution of polar resonance structure of the introduced substituent and for the substituent magnetic anisotropy effect, an excellent equation was obtained to relate, the chemical shifts of meta-substituted aromatic side chain protons to the Hammett’s constants.
The Insertion Reactions of Olefins into Metal-Ethyl Bonds in the Vanadium Compounds-Ethyl Aluminum Ziegler Catalyst System. A Proposed Mechanism for the Syndiotactic Polymerization of α-Olefin
Authors: Suzuki Toshimitsu , Takegami Yoshinobu
Published: July 2006

In order to clarify the mechanism of the syndiotactic polymerization of olefin, the insertion reaction of several olefins into metal-ethyl bonds in VCl4-AlEtnCl3−n, VOCl3-AlEtnCl3−n, and V(AA)3-AlEtnCl3−n systems were studied. Cyclohexene was easily inserted into metal-ethyl bonds in these catalysts to give a metal-ethylcyclohexyl bond at −70°C. Pentene-1 and 4-methylpentene-1 gave (Remark: Graphics omitted.) (I) and (Remark: Graphics omitted.) (II). At −70°C with VCl4-AlEt2Cl, where the syndiotactic polymerization of propylene proceeds, four times as much (II) as (I) was obtained. However, at 0°C or in the VCl4-AlEt3 catalyst system, the amount of (I) exceeded the amount of (II). With the VOCl3-AlEtnCl3−n or the V(AA)3-AlEt3Cl3−n system, the selectivity for the formation of metal-alkyl (II) was decreased. The above results lead to the conclusion that, in the course of syndiotactic polymerization, the secondary metal-alkyl bond (II) was an intermediate of the polymerization. By means of this mechanism every experimental result reported can be explained without difficulty.
Oxidative Ring-contraction of Several 1,5-Benzodiazepines with Light
Authors: Matsumoto Masakatsu , Matsumura Yoichi , Iio Akira , Yonezawa Teijiro
Published: July 2006

2,4-dimethyl- (I-a), 2-methyl-4-phenyl- (I-b), and 2,4-diphenyl-1,5-benzodiazepine (I-c) were irradiated with a high-pressure mercury arc under an oxygen atmosphere in benzene and in acetic acid. In all cases oxidative ring-contraction products, 2-acylquinoxalines (II), were obtained. It was found that there was a solvent effect in these reactions ; e.g., in benzene the diazepine (II-d) leads to 2-benzoyl-3-methylquinoxaline (II-d), while in acetic acid it leads to 2-acetyl-3-phenyl-quinoxaline (II-b).
Reactions of Diazoketones in the Presence of Metal Chelates. III. Reactions with Carbonyl Compounds
Authors: Takebayashi Matsuji , Ibata Toshikazu , Ueda Kozaburo
Published: July 2006

The reaction of α-diazoacetophenone with carbonyl compounds such as benzaldehyde, acetophenone and p-phenylacetophenone, has been studied in the presence of bis(acetylacetonato) copper (II). The reaction gave the corresponding tetrahydrofurans and dioxolanes accompanied by some by-products derived from benzoylcarbene. The mechanism of the reaction has been discussed in terms of an intermediate with a structure of betaine type, produced by the reaction of a ketocarbene-metal chelate complex with carbonyl compounds.
Studies of Diazosulfides. II. The Dissociation of trans- and cis-Diazosulfides and the Isolation of cis-Diaryldiazosulfides
Authors: Yamada Takashi
Published: July 2006

The reaction of trans- and cis-N-aryl-S-triphenylmethyldiazosulfides (I) with β-naphthol in alkaline ethanol was investigated. It was found that the dissociation of I occurs not only with the cis isomers, but also with the trans isomers, even in the dark. The kinetic study suggested that the trans-diazosulfides can dissociate not only through the cis form, but also directly, contrary to Zwet and Kooyman’s suggestion. The dissociation of the trans isomer of diaryldiazosulfides (II) was also discussed analogously. Further, by a preparation at −78°C several cis-diaryldiazosulfldes were isolated which had never before been isolated. The rate constant of the isomerization of cis-N-(p-cyanophenyl)-S-(p-toly)diazosulfide (IIf) was 2.55×10−3 sec−1 (at 0°C, in ethanol) ; this value is much larger than that for cis-I.
Rhodium Tolane Complex and Cyclotrimerization of Substituted Acetylenes Catalyzed by Transition Metal Complexes
Authors: Iwashita Yuji , Tamura Fumihide
Published: July 2006

Cyclotrimerization of tolane and phenylacetylene has been studied from the viewpoint of the reaction intermediates and the composition of reaction products. Rh4(CO)12 and Co4(CO)12 have been found to catalyze the trimerization of tolane and phenylacetylene to yield some substituted benzenes. By the reaction of Rh4(CO)12 with tolane, an unknown complex was obtained. The triphenyl phosphine derivative of this complex has been determined to be Rh2(CO)3(C6H5C≡CC6H5)2P(C6H5)3. From infrared spectroscopic study, it was concluded that the two tolane molecules in the complex are connected to rhodium atoms separately without completion of dimerization. On the basis of the ratio of 1,2,4-triphenylbenzene to 1,3,5-triphenylbenzene, the reaction course of trimerization is discussed.
Synthetic Studies of the Flavone Derivatives. XVII. Synthesis of 5,7-Dihydroxy-6-methoxyflavone Derivatives
Authors: Fukui Kenji , Nakayama Mitsuru , Horie Tokunaru
Published: July 2006

2,4-Dibenzyloxy-6-hydroxy-3-methoxyacetophenone was esterified with 3,4-disubstituted benzoyl chlorides, and the resulting esters were converted into 7-benzyloxy-5-hydroxy-6-methoxyflavone derivatives via the corresponding diketones. The catalytic hydrogenolysis of the benzyloxyflavones gave the desired 5,7-dihydroxy-6-methoxyflavones. Ethyl ethers of these flavones were also prepared from 2,4-diethoxy-3-methoxy-6-hydroxyacetophenone by an unambiguous method. 6,3′-Dimethoxy-5,7,4′-trihydroxyflavone, desmethoxycentaureidin (6,4′-dimethoxy-5,7,3′-trihydroxyflavone), and 6-methoxyluteolin (6-methoxy-5,7,3′,4′-tetrahydroxyflavone) were thus prepared.
Reaction of p-Nitrophenyl Sulfate with Thiophenol
Authors: Kurusu Takehiko , Tagaki Waichiro , Oae Shigeru
Published: July 2006

The reaction of p-nitrophenyl sulfate with p-substituted thiophenols were carried out in aqueous dimethylformamide under varying conditions. The rate was found to be independent of the concentration of thiophenolate, and to vary very little with the change of substituent. The Hammett correlation with σ value gives ρ=0.12. There was no rate-change in the pH range 6–12. Those observations seem to suggest the reaction to be of A-1 type.
The Total Synthesis of (±)-Isoelliptone
Authors: Harano Teruo
Published: July 2006

The condensation of 2′-hydroxy-4′,5′-dimethoxyfurano[3″,2″ : 6,7]isoflavone with ethyl bromoacetate in the presence of potassium carbonate gave the 2′-phenoxyacetate derivative. The subsequent treatment of this compound with dilute alkali gave isoelliptic acid. By the ring closure of the acid with acetic anhydride and anhydrous sodium acetate, or by the treatment of its ester with sodium methoxide, dehydroisoelliptone was obtained. The reduction of this compound with sodium borohydride, followed by Oppenauer oxidation, yielded isoelliptone, via a reduced compound, isoelliptol.
Reaction Intermediates in γ-Irradiated Mercaptans at 77°K
Authors: Torikai Ayako , Sawada Shuzo , Fueki Kenji , Kuri Zen-ichiro
Published: July 2006

Elementary processes in the radiolysis of ethyl mercaptan has been investigated by both spectrophotometric and electron spin resonance (ESR) methods. Ethyl mercaptan (C2H5SH) forms a glassy solid at 77°K, and when irradiated with γ-rays from Co-60, it develops a deep orange color; this color fades upon illumination with visible light, leaving a clear yellow color. The ESR spectrum of γ-irradiated C2H5SH at 77°K consists of two components; one is a complex spectrum which has been identified with the spectrum of C2H5S·, while the other is a photobleachable broad singlet which has been assigned to the ionic species. The C2H5S· radical shows an absorption spectrum with λmax=405 nm. The G-values for the formation of the radicals and the ionic species were 0.5 and 2.9 respectively. Studies of 2-methyltetrahydrofuran and butyl chloride solutions of C2H5SH were performed to identify these ionic species. Some significant elementary processes will be discussed on the basis of these results.
Hydrogen Formation in the Radiolysis of Saturated Hydrocarbons in the Liquid and Solid Phases. Effect of Temperature
Authors: Kimura Toyoaki , Fueki Kenji , Kuri Zen-ichiro
Published: July 2006

Hydrogen yields have been determined for thirteen saturated hydrocarbons (n-pentane, cyclopentane, methylcyclopentane, 3-methylpentane, n-hexane, cyclohexane, methylcyclohexane, n-heptane, n-octane, 2,2,4-trimethylpentane, n-nonane, n-decane and polyethylene) γ-irradiated at 20°C, −72°C and −196°C. The decrease in hydrogen yield with decreasing temperature from 20°C to −196°C has been correlated with the yield of thermal hydrogen atoms, which was obtained by adding ethylene as a scavenger at 20°C; the decrease in most cases was nearly equal to a half of the thermal hydrogen atom yield. Evidence of thermal hydrogen atom production at −196°C has also been demonstrated by ESR measurement. It has been concluded that thermal hydrogen atoms abstract hydrogen atoms from solvent molecules at 20°C, but they mostly recombine with each other to form hydrogen molecules at −196°C. An empirical formula based on the C–H bond parameter has been presented which is adapted for the hydrogen yield from normal alkanes.
Effects of Alkyl Halides on the γ-Ray Induced Polymerization of Ethylene in Liquid Carbon Dioxide
Authors: Hagiwara Miyuki , Okamoto Hidemasa , Kagiya Tsutomu
Published: July 2006

The 60Co γ-ray induced polymerization of ethylene in a liquid carbon dioxide solvent was carried out under a pressure of 400 kg/cm2 at 30°C in the presence of such alkyl halides as CH2Cl2, CHCl3, CCl4, C2H5Cl, C2H5Br, C2H5I, C2H4Cl2, C2H2Cl4, C2Cl6, C2F6, C2F5Cl, C2F4Cl2, C2H3Cl3, and C2F2Cl4, and their effects on the polymerization rate and the molecular weight of the polymer formed were investigated. Both the rate and the molecular weight were increased by adding C2F4-Cl2, C2F5Cl, and C2F6. A study of the radiolysis of these three fluorocarbons by mass spectrometric analysis showed that bond scissions of these substances took place mainly at the C–G bond. When other halogen compounds besides the three fluorocarbons were added to the reaction mixture, the rate and the molecular weight were decreased and C–X (X: halogen) bond scission was predominant in those substances. On the basis of these results, the role of the additives in the polymerization was discussed in relation to their radiolysis reactions.
Preparation and Circular Dichroism of trans(N) and cis(N) Isomers of (l- or d-Alaninate-N,N-diacetato)(amino-acidato)cobaltate(III) Complexes
Authors: Koine Norio , Sakota Naokazu , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

Eight new complexes, trans(N) or cis(N) isomers of (l- or d-alaninate-N,N-diacetato) (aminoacidato)cobaltate(III) ions, have been synthesized as their potassium salts, where the amino acids are glycine, l-alanine and l-proline. Stereoselective formation of a limited number of the isomers with respect to the geometrical arrangement of the coordinated nitrogen and oxygen atoms and with respect to the position of the chelate ring containing the methyl group of the coodinated alaninate-N,N-diacetate ion, were confirmd from the results of the studies by ion-exchange column chromatography, proton magnetic resonance and circular dichroism spectra. The additivity of vicinal circular dichroism contributions from the two different optically active ligands in a complex has been discussed for the complexes without the configurational chirality.
Gold Complexes of Schiff Bases obtained from Salicylaldehyde Derivatives and Alkyl Amines
Authors: Yamada Shoichiro , Yamanouchi Kuniko
Published: July 2006

Gold complexes (abbreviated as [AuIII(X-SAL·alkyl)2][AuICl2]) with salicylideneimine derivatives were prepared as red-brown crystals, where X denotes H, 5,6-benzo and 5-Cl. Since all these complexes are diamagnetic and exhibit similar electronic absorption spectra, the complexes of the [Au(X-SAL·R)2]+type are considered to have a similar configuration, namely a square-planar one. It should be noted that the complexes of the [Au(X-SAL·i-C3H7)2]+ type are also planar. The result is found to be similar to that for the palladium(II) and platinum(II) complexes, but different from that for the nickel(II) complexes.
Mechanism of the Ullmann Condensation. I. Kinetic and Thermodynamic Studies
Authors: Tuong Tran Dinh , Hida Mitsuhiko
Published: July 2006

Kinetic studies of the Ullmann condensation of an aryl halide, sodium 1-amino-4-bromoanthraquinone-2-sulfonate and an amine, aniline, were undertaken. Cupric copper was used as the catalyst. The reaction was found to be first order in monomeric aryl halide and first order in amine, and to depend hyperbolically on the concentration of the catalyst. It was shown by ESR measurements that the copper catalyst exists largely as cupric species. The experimental results were discussed mechanistically.
The Acid-catalyzed Cleavage of 2,6-Di-t-butyl-4-methyl-4-(1-phenylethyl)-cyclohexadien-1-one in the Hydroxylic Solvent. The Solvolysis of a Protonated Dienone
Authors: Okamoto Kunio , Nitta Issei , Shingu Haruo
Published: July 2006

In acetic acid, aqueous methanol, and phenol solvents, 2,6-di-t-butyl-4-methyl-4-(1-phenylethyl)-cyclohexadien-1-one (I) did not undergo a typical dienone-phenol rearrangement in the presence of sulfuric or perchloric acid, but yielded the solvolysis products, viz., 1-phenylethyl acetate, 1-phenylethyl methyl ether, and 1-phenylethyl phenyl ether, in the respective solvents, along with 2,6-di-t-butyl-4-methylphenol (II). The reactions carried out with the optically-active dienone (Ia) yielded solvolysis products which were predominantly racemized, but accompanied by a net inversion of the configuration. The polarimetric rate constant of racemization, measured in acetic acid containing sulfuric acid at 25°C, is in agreement with the spectrophotometric rate constants for the decrease in the dienone Ia and for the increase in the phenol II, essentially within the limits of experimental error. These stereochemical results can be accomodated by a typical SN1 mechanism, in which the dienone I, protonated on the carbonyl-oxygen, acts as a substrate, and the phenol II, as a leaving group.
3,4-Benzotropolone and Related Compounds. VIII. Azo, Nitro and Amino Derivatives of 6-Hydroxy-2,3-benzotropone
Authors: Hoshino Masamatsu , Ebine Seiji
Published: July 2006

On diazo coupling and nitration, 6-hydroxy-2,3-benzotropone (I) and its 5-bromo derivative (II) gave their 7-azo (V and VI) and 7-nitro substitution products (VII and VIII), respectively. In the same reactions, 7-bromo-6-hydroxy- (III) and 5,7-dibromo-6-hydroxy-2,3-benzotropones (IV) replaced their 7-bromo substituent to give the same 7-azo and 7-nitro substitution products as above. On nitration of III and IV, 2,2-dibromo- (IX) and 2,2,7-tribromo-4,5-benzocyclohepta-4,6-diene-1,3-diones (X) were also formed. Hydrogenation of V, VI, VII and VIII gave 7-amino-6-hydroxy-2,3-benzotropone (XI), diazotization of which gave 2-diazo-4,5-benzocyclohepta-4,6-diene-1,3-dione (XII). 7-Chloro-6-hydroxy-2,3-benzotropone (XV) was brominated to 2-bromo-2-chloro-4,5-benzocyclohepta-4,6-diene-1,3-dione (XVII) at room temperature, to 5-bromo-7-chloro-2,3-benzotropone (XVI) at 100°C, and to 2-chloro-2,7-dibromo-4,5-benzocyclohepta-4,6-diene-1,3-dione (XVIII) with excess bromine at 100°C. XVII and XVIII were easily debrominated to XV and XVI, respectively, on heating with hydrochloric or hydrobromic acid. XV changed into a mixture of I and II on heating with hydrobromic acid.
Pyrolytic and Photolytic Reactions. I. Thermal Rearrangement of 1-Acetyl- and 1-Isopropenyl-3-methylenecyclobutane
Authors: Ooba Shigehiro , Ohta Masaki , Kato Hiroshi
Published: July 2006

1-Acetyl- and 1-isopropenyl-3-methylenecyclobutane (I and II) were prepared and then subjected to pyrolysis. The pyrolysis of I at 304–340°C gave 2-methyl-5-methylene-Δ2-dihydropyrane, which was then converted to 4-methylenecyclohexanone at this temperature. The pyrolysis of II at 255–340°C gave 1-methyl-4-methylenecyclohexene, which was disproportionated at this temperature to p-xylene and 1,4-dimethylcyclohexene. In neither case was fragmentation to olefins observed. These results were interpreted by a two-step biradical mechanism.
The Migration of the Alkyl Groups of 6-Acetyl and 6-Methoxycarbonyl Derivatives of 2,3-Dimethyl-5-alkylbenzofurans
Authors: Kawase Yoshiyuki , Takata Setsuko , Miwa Toshio
Published: July 2006

The migration of the 5-alkyl groups of 2,3-dimethyl-5-alkyl-6-benzofuranyl methyl ketones by aluminum chloride was studied further, and an analogous migration was observed in the cases of methyl 2,3-dimethyl-5-alkyl-6-benzofurancarboxylates. The 5-ethyl-, 5-n-propyl-, and 5-isopropyl-ketones were converted to the corresponding carboxylic acids by the bromoform reaction and then, further, to the esters. The action of aluminum chloride on the 5-n-propyl-ketone and the esters in carbon disulfide at room temperature afforded the corresponding 4-alkyl-compounds as a result of the migration of the 5-alkyl groups to the 4-position, analogously to the way in which the 5-ethyl- and 5-isopropyl-ketones had afforded two 4-alkyl-ketones. The structures of the compounds were confirmed by converting both the ketones and the esters to the same carboxylic acids and from the data of their IR, UV and NMR spectra and gas chromatograms. It was found that the 5-alkyl groups were less likely to migrate in the cases of the esters than the corresponding alkyl groups in the cases of the ketones, while the n-propyl groups of the ketone and the ester were less likely to migrate than the other alkyl groups, and that the migration seemed to be intramolecular, as the n-propyl group was not isomerized to an isopropyl group during the migration.
Chromatographic Resolution of Several Racemates by Means of Optically Active Acidic Polymers Derived from α-Amino Acids
Authors: Yamashita Tetsushi , Nakamura Nobuo
Published: July 2006

The chromatographic resolution of several racemic amines was investigated by using three types of copolymers composed by N-acroylated α-amino acid and N,N′-dimethacroylhexamethylenediamine. The anilides of Dl-phenylalanine and Dl-valine, and of Dl-phenylglycine and Dl-1,2-diphenylethylamine, were partially resolved. The combination of substrate and sorbent giving the most efficient resolution was anilide of phenylglycine and the copolymer involving l-phenyl-alanine.
Reaction of 2-Aminobenzophenones with Aliphatic Acids in the Presence of Polyphosphoric Acid
Authors: Ishiwaka Takumi , Yonemoto Mitsuo , Isagawa Kakuzo , Fushizaki Yasaburo
Published: July 2006

The reaction of 2-aminobenzophenones with aliphatic acids, such as acetic acid, propionic acid, n-butyric acid, and bromoacetic acid, in the presence of polyphosphoric acid afforded 6-substituted 2-anilino-4-phenylquinoline derivatives in fairly good yields. Some of these quinolines were acetylated in the usual way, and the products, 2-(N-acetylanilino) quinolines, were treated with sodium ethoxide to give 1-quinolyl-2(1H)-quinolone derivatives. 2-Amino-5-chlorobenzophenone (Ic) reacted with an equimolar amount of 2-acetamido-5-methylbenzophenone to give 2-(2-benzoyl-4-methylanilino)-6-chloro-4-phenylquinoline, which was also obtained from the reaction of 2,6-dichloro-4-phenylquinoline with Ib in the presence of copper powder. It was found that the reaction mechanism in the formation of 2-anilinoquinolines is similar in type to that in Friedländer’s reaction. Furthermore, the structures of the 2-anilinoquinolines are discussed on the basis of our NMR spectral study.
Yields of Methylcyclohexanone Intermediates in the Hydrogenation of Isomeric Cresols over Ruthenium and Palladium Catalysts
Authors: Takagi Yuzuru , Nishimura Shigeo , Hirota Kozo
Published: July 2006

Isomeric cresols have been hydrogenated over ruthenium and palladium catalysts at elevated temperature and pressure. The yields of the methylcyclohexanone intermediates formed were estimated by application of a kinetic method. Hydrogenation with ruthenium catalyst gave 77, 61 and 60% of the ketone as the intermediate for o-, m- and p-cresol, respectively, while with palladium catalyst all isomeric cresols yielded the ketone intermediates quantitatively. The hydrogenation pathways leading to the formation of methylcyclohexanones were discussed. The stereochemistry of hydrogenation of isomeric cresols and methylcyclohexanones were also studied, and the results were interpreted on the basis of the estimated yields of the ketone intermediates.
Studies of Peptide Antibiotics. XIX. Syntheses of 1,1′-Leucine-gramicidin S and 1-Leucine-cyclosemigramicidin S
Authors: Kondo Michio , Izumiya Nobuo
Published: July 2006

Analogs of gramicidin S, 1,1′-l-leucine-gramicidin S (XI) and 1-l-leucine-cyclosemigramicidin S (XII), have been synthesized and tested for antibacterial properties. The cyclization reaction of a linear decapeptide active ester, in which δ-amino functions of ornithine residues were protected with benzyloxycarbonyl groups, yielded exclusively a protected cyclic decapeptide which was hydrogenated to afford the dihydrochloride of XI. A linear pentapeptide active ester afforded a mixture of protected cyclic penta and decapeptide. The pure protected cyclic pentapeptide was obtained with the use of a Sephadex LH-20 column, and the hydrogenolysis of the product afforded the hydrochloride of XII. The decapeptide analog (XI) was as active as natural gramicidin S, whereas the pentapeptide (XII) showed no activity toward any of the microorganisms tested.
Poly-β-Amino Acids. I. The Preparation of Phenyl Substituted β-Amino Acid Polymers
Authors: Yuki Heimei , Taketani Yutaka , Yamashita Shuzo , Okuno Hiroshi , Tanaka Hiromichi
Published: July 2006

α-Phenyl-, β-phenyl-, and α,β-diphenyl-β-aminopropionic acid were synthesized. Their polymers were obtained in good yields when the p-nitrophenyl esters of β-amino acids were polymerized at 60°C. The ethyl esters gave low-molecular-weight polymers in poor yields at 150°C in vacuo. By the thermal polycondensation of β-amino acids themselves at 250°C, polymers were not obtained, but the corresponding cinnamic acid derivatives were obtained by the intramolecular β-elimination reaction. Poly(α-phenyl-β-amino acid), and poly(β-phenyl-β-amino acid) were soluble in trifluoroacetic acid, and chloroform containing a small amount of dichloroacetic acid. On the other hand, poly(α,β-diphenyl-β-amino acid) was soluble only in cone, sulfuric acid, while it was insoluble in usual organic solvents. The DP of poly(β-phenyl-β-amino acid) was about 18. None of the polymers showed any melting point below 300°C.
Study on Oxazolopyrimidines. I. Synthesis and Spectroscopic Properties of 7-Aminooxazolo[5,4-d]pyrimidines
Authors: Ohtsuka Yozo
Published: July 2006

Several 2- and 5-substituted oxazolo[5,4-d]pyrimidines have been prepared from 5-amino-4-cyanooxazole derivatives via  N-ethoxymethylene intermediates in order to compare them with purine derivatives. Spectroscopic data and some chemical properties of these compounds were examined. A convenient method for the preparation of a starting material was described.