bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rhodium Tolane Complex and Cyclotrimerization of Substituted Acetylenes Catalyzed by Transition Metal Complexes
Authors: Iwashita Yuji , Tamura Fumihide 
Published: July 2006

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Calculation of the Chemical Shifts by the Semi-empirical SCF MO Method for All Valence-elctron Systems
Authors: Katô Hajime , Kato Hiroshi , Yonezawa Teijiro 
Published: July 2006

Abstract
The proton chemical shifts in the nuclear magnetic resonance spectra of CH4, C2H6, C2H4, H2CO, pyridine, and protonated pyridine were evaluated on the basis of Pople’s theory (J. Chem. Phys., 37, 53 (1962)) in which the shielding tensor is expressed in terms of the magnetic susceptibility of each atom in the molecule. The wave functions were obtained using a semi-empirical SCF MO method for valence-electron systems (Bull. Chem. Soc. Jap., 40, 536, 1017 (1967)). The 13C- and 14N- chemical shifts in the above compounds were calculated on the basis of the “Coupled Hartree-Fock perturbation theory.”
Chemical Reaction in Silent Electric Discharge. I. The Mechanism of Ozone Formation
Authors: Sugimitsu Hidetoshi , Asakura Ryozo , Okazaki Satiko , Suzuki Momotaro 
Published: July 2006

Abstract
The ozone formation reactions in the silent electric discharge starting from oxygen under atmospheric pressure and varied electric conditions were investigated. The results were found to be in line with the theory based on the postulates of reactional and electrical pattern, proposed earlier by authors. The reaction regime in discharge columns where the main reactions proceed is unusual. The duration of high frequency discharge which initiates the primary reactions is extremely short compared to the apparent duration of discharge of basic primary current. Thus, in the discharge columns a non-steady reaction regime is established. A rate theory is developed for the processes in silent discharge based on a non-steady state assumption, which is acceptable in view of the experimental results. The proposed pattern of processes is useful for obtaining more detailed mechanism of the reaction involved.
Crystal Structure of Bis(nitrosocyclohexane)
Authors: Tanimura Masamitsu , Kobori Kiyotomi , Kashiwagi Michio , Kinoshita Yukio 
Published: July 2006

Abstract
The crystal structure of bis(nitrosocyclohexane), (C6H11NO)2, has been determined by means of three-dimensional X-ray analysis by the photographic method. The crystal belongs to the triclinic space group P \bar1, with cell parameters, a=10.133 A, b=6.758 A, c=5.583 A, α=121°42′, β=96°50′, γ=78°06′. The unit cell contains one molecule. The nitrogen and oxygen atoms and the carbon atoms bound to nitroso-groups, CNO–O′N′C′, are almost coplanar, and the oxygen atoms take a trans configuration around the N–N′ bond. The cyclohexane ring takes a chair form and the nitrogen atom is bound to an equatorial bond. The CNO-O′N′C′ plane is twisted from the cyclohexane ring by 73°.
Radiotracer Studies on Adsorption of Surface Active Substance at Aqueous Surface. I. Accurate Measurement of Adsorption of Tritiated Sodium Dodecylsulfate
Authors: Tajima Kazuo , Muramatsu Mitsuo , Sasaki Tsunetaka 
Published: July 2006

Abstract
We carried out direct measurement of adsorbed amount at the air-solution interface to confirm the validity of the Gibbs adsorption equation by using radiochemically and surface chemically pure tritiated sodium dodecylsulfate (TSDS) and a sheet scintillation counter, which was developed for the purpose of counting β-rays of tritium in air. The adsorbed amount increased with increasing SDS concentration and showed the saturation values of 3.19×10−10 mol/cm2 in the concentration region from 3.2×10−3 to 14.4×10−3 mol/1000 g solution at 25°C. For the salt-free solution of ionic surfactant the Gibbs adsorption equation is confirmed to be valid for n=2 when activity in place of concentration is used. The equation of state for the ionic adsorbed film is further proposed. The cohesive pressure due to the attraction between hydrocarbon chains was given as a function of inverse molecular area.