bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study of Local Structure Formation in Binary Solutions of 2-Butoxyethanol and Water by Rayleigh Scatterring and Raman Spectra
Authors: Ito Nobuyuki , Fujiyama Tsunetake , Udagawa Yasuo
Published: July 2006

The concentration dependence of concentration fluctuations at 21, 32, and 42 °C and of Raman spectra at 21 °C were measured for binary solutions of 2-butoxyethanol (BE) and water. The existence of the two kinds of local structures is inferred; clathrate hydrate-like structure g[(H2O)50BE] and aggregate h[(H2O)4BE]. The compositions of these two structures are the same as those of the two phases into which the solution separates above the critical solution temperature. The phase separation is understood to be the end of the growth of the local structures, which already exist well below the critical solution temperature.
Reduction of Organic Sulfonic Acids, Sodium Sulfonates, and Sulfonic Esters to the Corresponding Disulfides with Polyphosphoric Acid Derivatives, Potassium Iodide and Tetrabutylammonium Iodide System
Authors: Oae Shigeru , Togo Hideo
Published: July 2006

Organic sulfonic acids, sodium sulfonates, and alkyl sulfonates were readily reduced to the corresponding disulfides in moderate yields upon treatment with a mixture of a polyphosphoric acid derivative and iodide. In these reactions, formation of mixed anhydrides each having a P–O–S linkage is the key step, and subsequent attack of iodide on the sulfur atom gives the corresponding sulfonyl iodides which are reduced further exothermally to the disulfides with hydrogen iodide. Actually, p-toluenesulfonyl chloride was isolated in the reaction of p-toluenesulfonic acid and polyphosphoric acid derivatives with chloride ion. The competitive reduction of various aromatic sulfonic acids reveals that an aromatic sulfonic acid bearing an electron-donating para-substituent is more readily reduced to the disulfide than that which has an electron-withdrawing para-substituent.
Electrical Dark- and Photo-conductivities of 2-(p-Decyloxybenzilideneamino)-9-fluorenone in the Nematic State
Authors: Okamoto Ken-ichi , Nakajima Shu , Ueda Michiko , Itaya Akira , Kusabayashi Shigekazu
Published: July 2006

The electrical conductivity of 2-(p-decyloxybenzylideneamino)-9-fluorenone (DBAF), which has a large π-electronic group, was investigated in the nematic state. The dark conductivity showed a positive anisotropy and was attributed to ionic conduction. The photocurrent was observed in the absorption region of DBAF and was enhanced by doping with 2,4,7-trinitro-9-fluorenone. The photocarriers seem to be generated from the excited state of DBAF by one photonic process.
Studies of Cyanamide Derivatives. Part 109. A Convenient Method for Preparation of 4-Aminothiazole Compounds from Alkoxythiocarbonylcyanamide Salts
Authors: Fuchigami Toshio , Yeh Mou-Yung , Nonaka Tsutomu , Tient Hsien-Ju
Published: July 2006

α-Halo derivatives of ketones, ester, and nitrile reacted readily with potassium ethoxythiocarbonylcyanamide to provide the corresponding 4-amino-2-ethoxythiazole compounds in good yields, while α-halo amide did not. In a similar manner, α,α′-dihalo ketone reacted with 2 equiv of alkoxythiocarbonylcyanamide and S-methyl N-cyanocarbamodithioate salts to give the corresponding bis(4-amino-5-thiazolyl) ketones.
Preparation and Chelation Properties of Polystyrene–Divinylbenzene Copolymer Resins Containing Pyridylamines, Salicylamine, and 2-Thenylamine
Authors: Yokoyama Toshiro , Kikuchi Atsushi , Kimura Tetsuo , Suzuki Toshishige M
Published: July 2006

Bidentate and tridentate ligands, 2-pyridylmethylamine, N-[2-(2-pyridyl)ethyl]ethylenediamine, salicylamine, and 2-thenylamine are incorporated into polystyrene–2%-divinylbenzene copolymer beads. These chelating resins are evaluated for their chelation capacity toward transition metal ions (Co2+, Ni2+, Cu2+, and Zn2+) at various pH. The chelating resins containing pyridine derivatives show a high capacity and selectivity. The selectivity of the resins for the metal ions is in the order, Cu2+>>Ni2+>Co2+≥Zn2+ which is in accord with the order of the formation constants of the introduced ligands. Separation of a metal ion mixture (Cu2+, Ni2+, Zn2+) into its components is undertaken by a column containing the chelating resin derived from N-[2-(2-pyridyl)ethyl]ethylenediamine. The present resins can also be used for the elimination of trace amount of harmful heavy metal ions such as Hg2+ and CrO42−.
Regioselective Carboxylation of 9-Xanthenones with Manganese(III) Acetate
Authors: Nishino Hiroshi , Kurosawa Kazu
Published: July 2006

Seven 9-xanthenones were oxidized with manganese(III) acetate to give carboxy-, dicarboxy-, (acetoxymethyl)(carboxy)-, (carboxy)(hydroxymethyl)-, and acetoxymethyl-9-xanthenones, and to yield small amounts of (carboxymethyl)(carboxy)-, carboxymethyl-, (acetoxymethyl)(carboxymethyl)-, bis(acetoxymethyl)-, and diacetoxymethyl-9-xanthenones. The carboxyl group was preferentially introduced into the peri positions and the acetoxymethyl groups were located at positions ortho to the methoxyl or methyl group. The regioselectivity and mechanism of the carboxylation reaction is discussed briefly.
N-Methyl-N-(phenylsulfonyl)benzohydrazonoyl Chloride as a Potential Intermediate for Nitrogen-heterocycles. Preparation of 1-Methyl-3-phenyl-1H-1,2,4-triazoles and -pyrazoles
Authors: Ito Suketaka , Tanaka Yumo , Kakehi Akikazu , Fukuyama Toshihiko , Osawa Nobuo , Sayo Noboru
Published: July 2006

3,5-Disubstituted 1-methyl-1H-1,2,4-triazoles and -pyrazoles were obtained in good to moderate yields by the reaction of N-methyl-N-(phenylsulfonyl)benzohydrazonoyl chloride with nitriles and with acetylenes in the presence of aluminum chloride. The triazoles were also formed by the reaction of acid chlorides with N-methyl-N-(phenylsulfonyl)benzamidrazone which was generated from the hydrazonoyl chloride and ammonia.
Phase Behavior of 2-Butoxyethanols/Water/Oil Systems
Authors: Kunieda Hironobu
Published: July 2006

Phase diagrams of 2-isobutoxyethanol (D)/water (W)/decane (O) system were studied at 2.0, 8.2, 15.0, 19.0, and 19.8 °C. The addition of O lowers the critical solution temperature of the D–W system from 26.2 to 2.0 °C, at which temperature the critical solution curve ends with the lower critical end point (Kc). On the other hand, the addition of W raises the critical solution temperature of the O–D system to 19.8 °C at which the critical solution curve ends with another critical end point (Lc). A three-phase region consisting of O, D, and W phases appears in a temperature range between the two critical end temperatures.
The Wallach Rearrangement of Some 4,4′-Disubstituted Azoxybenzenes
Authors: Shimao Ichiro , Oae Shigeru
Published: July 2006

The treatment of azoxybenzenes bearing electron-withdrawing substituents at 4,4′-positions with sulfuric acid gave the corresponding 2-hydroxyazobenzenes, together with 4′-substituted 4-hydroxyazobenzenes. The treatment of 4,4′-dimethoxyazoxybenzene with p-toluenesulfonic acid and acetic anhydride afforded 4,4′-dimethoxy-3-acetoxyazobenzene and 4,4′-dimethoxy-2-tosyloxyazobenzene as the main rearrangement products.
Radical Formation through Curing Reaction of Epoxy Resins with 2,4,6-Trinitrophenol or 2,4,6-Trinitroresorcinol
Authors: Kawamura Kazuro
Published: July 2006

Radicals formed spontaneously during the cure reaction of epoxy resins with 2,4,6-trinitrophenol (TNP) or 2,4,6-trinitroresorcinol (TNR) have been investigated using electron spin resonance (ESR) technique. The ESR spectrum of the radicals stabilized in the epoxy resins cured with TNP was a triplet and the other spectrum of the radicals in the epoxy resins cured with TNR was a triplet with high anisotropy. The triplet splittings and g-values were attributed to radicals of the type (Remark: Graphics omitted.). The asymmetric line shapes of the triplet splittings caused by the 14N coupling constant are induced by the slow motion of the radicals in the polymer. The presence of radicals of this type suggests the transfer of an oxygen of a nitro group of TNP or TNR during the cure reaction.
Association of β-Diketones with Trioctylphosphine Oxide in Solvent Extraction Systems
Authors: Sekine Tatsuya , Saitou Takashi , Iga Hiroto
Published: July 2006

Distribution of six β-diketones between hexane, benzene, carbon tetrachloride, or chloroform and 0.1 mol dm−3 aqueous perchlorate solutions has been measured in the presence of trioctylphosphine oxide (TOPO). The distribution ratio was, in many cases, enhanced by TOPO; this was explained in terms of association of the β-diketones and TOPO. The association constants were greater when the β-diketone was stronger as an acid and also in the following order of the diluent: CHCl3<CCl4<C6H6<C6H14. It was concluded that, even though the effect was not very large, still correction for the decrease in the concentrations of both the β-diketone and TOPO is necessary for an accurate estimation of the equilibrium involved in solvent extraction of metal ions containing these two reagents, as in the synergistic solvent extraction of metal ions.
An Electron Transfer Chain Mechanism for Photoinduced Oxidative Addition of Alkyl Iodide to a Dimeric Rhodium(I) Complex under Low Energy Irradiation (553 nm)
Authors: Fukuzumi Shunichi , Nishizawa Nobuaki , Tanaka Toshio
Published: July 2006

A dimeric RhI complex, [Rh2(dicp)4]2+ (dicp=1,3-diisocyanopropane) was found to undergo a photoinduced oxidative addition with butyl iodide and isopropyl iodide in MeCN by 553 nm irradiation in high quantum yields, Φ=25.2 and 22.6, respectively. Electron acceptors (p-dinitrobenzene, p-benzoquinone, and chloranil) and radical scavengers (oxygen and isopentyl nitrite) act as inhibitors for the photoinduced oxidative addition, providing unambiguous evidence for a chain character of this reaction. The fluorescence quenching of [Rh2(dicp)4]2+ by the electron acceptors as well as butyl iodide has also been examined. Based on the kinetics of the photochemical reactions in the absence or the presence of electron acceptors and radical scavengers, an electron transfer chain mechanism has been proposed. The formation of butyl radicals in the photoinitiation step was confirmed by the trap with oxygen to yield equimolar amounts of 1-butanol and butyraldehyde. The nature of the excited state of [Rh2(dicp)4]2+*(1A2u or 3A2u) involved in the photoinitiation step has also been discussed.
Binuclear Metal Complexes. LI. Synthesis and Characterization of the Tetrachloro-o-benzoquinone Adducts of Binuclear Iron(II) Complexes with 2-(Salicylideneamino)phenol and Its Substituted Homologs
Authors: Kanda Wakako , Nakamura Masaaki , Okawa Hisashi , Kida Sigeo
Published: July 2006

Binuclear iron(III) complexes Fe2(R-R′-sap)2(tcoq) have been prepared by the oxidation of binuclear iron(II) complexes Fe2(R-R′-sap)2 with tetrachloro-o-benzoquinone (TCOQ), where H2(R-R′-sap) represents 2-(salicylideneamino) phenols with the substituent R on the salicylaldehyde ring and the R′ on the o-aminophenol ring. Magnetic measurements indicated the operation of an intramolecular antiferromagnetic spin-exchange interaction between the iron(III) ions, the exchange integrals being evaluated at −6–−10 cm−1. In both polarograms and cyclic voltammograms of these complexes, two redox processes attributable to Fe(III)–Fe(III)\ightleftharpoonsFe(III)–Fe(II)\ightleftharpoonsFe(II)–Fe(II) were observed.
Studies of Bitter Peptides from Casein Hydrolyzate. I. Synthesis of Bitter Peptide BPIa Corresponding to Arg–Gly–Pro–Pro–Phe–Ile–Val from Casein Hydrolyzate by Alkaline Proteinase of Bacillus subtilis
Authors: Fukui Hiroshi , Kanehisa Hidenori , Ishibashi Norio , Miyake Ichizo , Okai Hideo
Published: July 2006

A bitter heptapeptide BPIa was synthesized and compared with the natural peptide, isolated by Minamiura et al. from casein hydrolyzate, by means of thin layer chromatography, paper electrophoresis, and carboxymethylcellulose column chromatography. All results for the two peptides matched very closely each other. The synthetic BPIa has an extremely bitter taste with its threshold value 0.05 mM. It is one of the most bitter compounds such as phenylthiourea and quinine.
Stereochemistry of the Palladium-catalyzed Hydrogenation of 3-Oxo-4-ene Steroids. V. A Kinetic Study in Basic and Acidic Media
Authors: Nishimura Shigeo , Momma Yasuhiro , Kawamura Hideo , Shiota Michio
Published: July 2006

Effects of the β-methyl group at C-10 and some oxygen functions (=O, OH, OAc) at C-11, C-17, and C-20 on the rates of hydrogenation of 3-oxo-4-ene steroids have been studied with palladium catalyst in pyridine or THF/HBr as solvent. In contrast to the hydrogenation in pyridine, the rate in THF/HBr was greatly depressed by the presence of 10β-methyl group. The reactivity of the steroids was enhanced by the oxygen functions, in particular, by 11, 17-dioxo group. The effects of the substituents are discussed from a mechanistic consideration based on the obtained results.
Viscosities of Aqueous Solutions of Alkanoic Acids
Authors: Miyajima Koichiro , Sawada Masahiro , Nakagaki Masayuki
Published: July 2006

Viscosities of aqueous solutions of alkanoic acids including formic acid were measured by an Ostwald type viscometer at 15, 25, and 35 °C, and the viscosity B-coefficient and the temperature dependence of B-coefficient, dB⁄dT, were calculated. From the signs and the magnitudes of Bst, increment of B-coefficient arising from the change of water structure, and dB⁄dT, it was concluded that formic acid was a hydrophilic structure breaker, while acetic acid was neither a structure maker nor a structure breaker. Both propionic acid and butyric acid were the hydrophobic structure makers. The mechanism of structure breaking effect of carboxyl group was briefly discussed.
Mechanism of Chlorine Catalytic Oxidation of CO in the Gas Phase
Authors: Ohta Tomohiro
Published: July 2006

The mechanism of the title reaction is determined under steady state conditions by the irradiation of the mixtures of Cl2, CO, O2, and N2 at 300 K with black blue fluorescence lamps using infrared spectroscopy. The pressure dependence of the ratio of the formation rate of carbon dioxide to that of phosgene (COCl2) and the other results indicated that the oxidation of CO proceeded via intermediates ClCO and ClC(O)O2 as the termolecular process rather than the bimolecular oxidation by ClOO and/or ClO. The ratio of the competitive reactions of chloroformyl radicals, k8⁄k9a, was found to be (6.5±0.4)×10−2 in the total pressure range from 30 to 755 Torr (1 Torr=133 Pa); ClCO+Cl2→COCl2+Cl (8), ClCO+O2→ClC(O)O2* (9a). And also, the ratio of the competitive reactions of the vibrationally excited intermediates, k9b⁄k9c, was (3.4±0.3)×1018 molecule/cm3; ClC(O)O2*→ClCO+O2 (9b), ClC(O)O2*+M→ClC(O)O2+M (9c). The role of this reaction in the stratosphere is discussed and estimated to be unimportant.
Catalytic Alkylation, Sulphonation, and Heteroarylation of Some Bicyclic Pyrazolines in Solid-Liquid Two Phase Systems
Authors: El-Shafei Ahmed Kamal , El-Sayed Ahmed Mahmoud , Khalaf Ali Ali
Published: July 2006

The reaction of some bicyclic pyrazolines with alkyl halides, aryl sulphonyl chlorides as well as with some N–H and S–H containing heterocycles is affected in solid-liquid two phase systems using a catalyst. The catalytic cycle is described, the purity of the obtained products is checked using TLC and their structure is confirmed by a combination of chemical and spectroscopic methods.
Absorption Intensity of Charge-transfer Transition between Ion Radicals in One-dimensional System of Crystalline Ion Radical Salts
Authors: Iida Yôichi
Published: July 2006

The charge-transfer interaction between ion radicals in crystalline ion radical salts was examined with one-dimensional Hubbard model. The intensity of charge-transfer absorption in crystal electronic spectra was estimated with both simple and complex ion radical salts. This approach was then applied to simple cation radical salt of Phenothiazine+·Br− and complex cation radical salt of (Phenothiazine)2+·Br−.
The Quenching of the OH (2Σ+) Produced in the H2–O2 Reaction by Collision with Ar
Authors: Hidaka Yoshiaki , Kawano Hiroyuki , Suga Masao
Published: July 2006

H2–O2 mixtures highly diluted with Ar were heated to temperatures in the range of 1200–1800 K behind reflected shock waves. The OH*-emission intensity was then measured to determine its quenching-rate constant upon collision with Ar; this constant was found to be about 1/164 of that in the case of H2O.
An Odorless Preparative Method of Sulfides and Thiocarboxylic S-Esters Using 3-(Alkylthio)-1,2-benzisothiazole 1,1-Dioxide
Authors: Yamada Hiroyuki , Kinoshita Hideki , Inomata Katsuhiko , Kotake Hiroshi
Published: July 2006

It was found that sodium salt of 1,2-benzisothiazole-3(2H)-thione 1,1-dioxide (thiosaccharin) readily reacted with alkyl halide affording 3-(alkylthio)-1,2-benzisothiazole 1,1-dioxide (3). Treatment of 3 with piperidine produces the corresponding alkanethiol in situ quantitatively and subsequent treatment with various electrophiles gives the corresponding sulfides and thiocarboxylic S-esters in good yields.
Catalytic Activity of PdCl2 Complexes Having Sulfur Compounds as Ligands
Authors: Ogura Katsuyuki , Aizawa Teruki , Uchiyama Koichiro , Iida Hirotada
Published: July 2006

The PdCl2 complexes coordinated with methyl p-tolyl sulfoxide (1:2), methylthiomethyl p-tolyl sulfoxide (1:2), and 1,3-bis[(p-tolylsulfinyl)methylthio]propane (1:1) as ligands were prepared. Among these complexes, bis(methyl p-toly sulfoxide)palladium dichloride catalyzed effectively cyclotrimerization of diphenylethyne and rearrangement of 3-acetoxy-1-tridecene to 1-acetoxy-2-tridecene.
Palladium-catalyzed Reaction of 4′-Iodobenzocrown Ethers with Acetylenes. Convenient Synthesis of Alkyl-substituted Benzocrown Ethers and Bis(benzocrown ether)s via Alkynyl-substituted Benzocrown Ethers
Authors: Kikukawa Kiyoshi , Abe Akito , Wada Fumio , Matsuda Tsutomu
Published: July 2006

4′-Iodobenzo-15-crown-5 and -18-crown-6 were alkynylated by heptyne, propargyl alcohol, 1,7-octadiyne and acetylene in good yields with use of Pd(PPh3)2Cl2 and Cul as catalysts. The latter two acetylenes gave bis(crown ether)s in one step. Hydrogenation of the alkynylated benzocrown ethers gave 4′-heptyl, 4′-(3-hydroxypropyl)benzocrown ethers and bis(benzocrown ether)s connected with ethylene or octamethylene linkage.
Importance of Work Terms in the Free Energy Relationship for Electron Transfer
Authors: Fukuzumi Shunichi , Kochi Jay K
Published: July 2006

The rates of arene and alkene brominations and mercurations, Diels-Alder cycloaddition as well as alkylmetal cleavages by electrophiles, electron acceptors and free atoms can be quantitatively analyzed in terms of the driving force for electron transfer. The single, unified free energy relationship for all of these rather disparate chemical processes relates the activation free energy to the standard free energy change for electron transfer and the work term for ion-pair formation. The latter is evaluated from charge transfer spectral data of the electron donoracceptor complexes formed as transient intermediates. The large variations in the apparent Brönsted slopes from unity to even negative values in these systems can be readily attributed to changes in the work terms arising from steric effects in ion-pair formation.
Effects of Alkyl Chain Length on Molecular Interactions. I. Solid Complex Formation in the Pyrene–N-Alkyl-2,4,6-trinitroaniline Systems
Authors: Togashi Atsushi , Matsunaga Yoshio
Published: July 2006

Phase diagrams were prepared for the fifteen binary systems consisting of pyrene as an electron donor and N-alkyl-2,4,6-trinitroanilines as electron acceptors. The thermal stability of the orange 1:1 complex between pyrene and the unsubstituted 2,4,6-trinitroaniline (mp 236 °C) is drastically decreased by N-alkylation; e.g., the N-pentyl-2,4,6-trinitroaniline complex melts at 97 °C. The systems with the N-hexyl and N-heptyl derivatives give two peritectics each, while most of the higher homologues produce a single peritectic or a eutectic. Unstable red solids were formed on rapid cooling of the molten pyrene–N-hexyl-2,4,6-trinitroaniline mixtures. This red complex becomes relatively more stable with increase of the alkyl chain length, possibly because of the enhanced tendency for chain alignment. In the systems with the N-pentadecyl and N-heptadecyl derivatives, the stable existence of the red 1:1 complex could be demonstrated.
Preparation of Aluminum Fluoride Film with Graphite Fluoride
Authors: Watanabe Nobuatsu , Ohara Hidehiko , Nakajima Tsuyoshi
Published: July 2006

An aluminum fluoride film covered by graphite fluoride on metallic aluminum was prepared by reaction in the ternary system of aluminum, graphite and fluorine gas at 450–550 °C. The film consisted of a large amount of aluminum fluoride covered by thin graphite fluoride layers. The contact angle of a water drop on the film was around 120°, which decreased to 85–95° during 45 d probably due to reaction with moisture and/or water drop. Almost no oxygen was detected in the film. The film formation would be based on the reduction of oxide layer on aluminum by carbon radical produced by thermal decomposition of graphite fluoride.
Ion Radicals of Organometallic Compounds. III. Positional Effects on the Thermodynamics of Formation and the Kinetics of Decomposition of (Methyl-substituted Benzene)tricarbonylchromium Cation Radicals
Authors: Ikeshoji Tamio , D. Parker Vernon
Published: July 2006

Reversible oxidation potentials, rate constants, and activation parameters are reported for the formation and decomposition reactions of all isomers of (methyl-substituted benzene)tricarbonylchromium cation radicals. The reversible potentials were observed to depend both on the number and the positions of the methyl substituents. It was found that the effects on the reversible potentials of adding single methyl substituents to similar structures were additive. The activation energies and entropies for the decomposition reactions were found to be grouped into four different categories depending upon the numbers of adjacent unsubstituted positions on the methylarene ligands. Within each group the deviations from the averages were less than experimental error. The differences in activation parameters are explained in terms of how effective bonding is between the chromium atom and the arene ligands in the cation radicals.
Copper(II)-Catalyzed Transamination of Hydrophobic Pyridoxamine with Pyruvic Acid in Functionalized Bilayer Vesicles
Authors: Murakami Yukito , Kikuchi Jun-ichi , Nakano Akio , Akiyoshi Kazunari , Imori Toru
Published: July 2006

The copper(II)-catalyzed transamination of 2-methyl-3-hydroxy-4-aminomethyl-5-(dodecylthiomethyl)pyridine (C12SPM) with sodium pyruvate was investigated in an aqueous medium at pH 6.8, μ 0.10 (KCl), and 30.0±0.1 °C in the presence of molecular aggregates of N,N-ditetradecyl-Nα-[6-(trimethylammonio)hexanoyl]-l-alaninamide bromide (N+C5Ala2C14), N,N-ditetradecyl-Nα-[6-(trimethylammonio)hexanoyl]-l-histidinamide bromide (N+C5His2C14), or hexadecyltrimethylammonium bromide (CTAB). The reaction afforded the corresponding pyridoxal analogue (C12SPL) and alanine as the final products upon addition of edta which liberates the copper(II) ion from the coordination sites of the aldimine Schiff-base. The coordination interaction between the copper(II) ion and C12SPM, which takes place prior to the transamination, was clarified by electronic spectroscopy. The reactivity of the 2:1 (ketimine:CuII) complex was found to be much larger than that of the 1:1 complex in the molecular assemblies of N+C5Ala2C14 and CTAB, and the formation of the former species was more pronounced in the N+C5Ala2C14 vesicle. The bilayer vesicle formed with N+C5His2C14 allowed the formation of the 1:1 complex in preference to that of the 2:1 complex, and the coordination-free imidazolyl group of the amphiphile effectively catalyzed the isomerization as a general base.
Rate and Equilibrium of the Hydration of 1,3-Benzodithiolylium Ion
Authors: Okuyama Tadashi , Fueno Takayuki
Published: July 2006

Rates and the equilibrium constant of hydration of 1,3-benzodithiolylium ion were spectrophotometrically measured at 30 °C in aqueous acidic solutions. The hydrate was stable below pH 5 and pKR+=−0.40. The cation does not seem to be very stable as compared with the corresponding dithiolanylium ion.
Quinazoline Derivatives from 2-Phenyl-4-quinazolinylhydrazine
Authors: El-Sherief Hassan Ahmed , Mahmoud Abdalla Mohamed , Esmaiel Ahmed Ahmed
Published: July 2006

Formic acid and acetyl and benzoyl chloride were treated with 2-phenyl-4-quinazolinylhydrazine (1) under mild conditions to afford the corresponding hydrazides which were converted into 5-phenyl[1,2,4]triazolo[1,5-c]quinazoline, 2-methyl-5-phenyl[1,2,4]triazolo[1,5-c]quinazoline, and 2,5-diphenyl[1,2,4]triazolo[1,5-c]quinazoline (3a) respectively by heating over their melting points. Reaction of 1 with aldehydes produced the corresponding hydrazones which give the corresponding [1,2,4]triazolo[1,5-c]quinazolines (3a–i) on pyrolysis. Carbon disulfide underwent ring closure with 1 to 5-phenyl-1,2,4-triazolo[4,3-c]quinazoline-3-thiol which was readily converted into the corresponding alkylthio compounds by treatment with alkyl halides. Further, 4-(4-arylmethylene-5-oxo-2-phenyl-2-imidazolinylamino)-2-phenylquinazolines were obtained via the condensation of 4-arylmethylene-2-phenyl-2-oxazolin-5-ones with 1.
Paramagnetic Cobalt(III) Complexes with Organic Ligands. VIII. The NMR Spectra of Paramagnetic Tetraammine(5-nitrosalicylato)cobalt(III) Chloride Nitrate Hydrate and the Related Compounds
Authors: Yamamoto Yoshihisa , Shimokawa Shigezo , Yamada Eiji
Published: July 2006

The ring proton signals have been assigned for the 1H NMR spectra of the green paramagnetic tetraammine(5-nitrosalicylato)cobalt(III) chloride nitrate hydrate and (quadridentate amine)(5-nitrosalicylato)cobalt(III) chloride nitrate hydrate, [Co(5-NO2sal)L]Cl·NO3·nH2O (L: (NH3)4, trien, 2,3,2-tet, and 3,2,3-tet). The 1H NMR spectra indicate that the unpaired electron on the coordinated 5-nitrosalicylato ligand of the title complexes is located over the π-orbital of the chelated ligand
Photoelectrochemical Oxidation of Alcohols on Polycrystalline Zinc Oxide
Authors: Lee Ju-seong , Kato Tamihiko , Fujishima Akira , Honda Kenichi
Published: July 2006

The current doubling behavior of alcohols was studied on an n-type ZnO polycrystalline electrode. The increase in photocurrent due to alcohols on the ZnO depended on pH of the solution. The photocurrent was almost doubled in alkaline solution. It was found that the ZnO photoanode dissolved in the neutral aqueous solution but the dissolution reaction of ZnO was completely suppressed in alkaline solution at a sufficiently large pH. From the experimental results obtained by the rotating ring disk electrode and gas chromatographic and mass spectrometric analyses, a mechanism of the current-doubling reaction is proposed.
The Willgerodt-Kindler Reaction between Polycyclic Aromatic Amines and Benzaldehyde. Formation of 1,3-Thiazines
Authors: Nomura Yujiro , Hayama Takashi , Takeuchi Yoshito , Tomoda Shuji , Kato Yuko
Published: July 2006

The title reaction performed under typical conditions of the Willgerodt-Kindler reaction afforded “abnormal” product 1,3-thiazines. A mechanism involving the Diels-Alder reaction between N-benzylidenearyl-amine and thiobenzaldehyde has been suggested to explain the formation of 1,3-thiazines.
NMR Study of Protonated Halothiophenes. II. An ab Initio Self-consistent Field Calculation of the Protonation of Chlorothiophenes
Authors: Yamashita Yukihide , Kobayashi Hiroyuki , Yoshino Akihiro , Takahashi Kensuke , Sone Tyo
Published: July 2006

The STO-3G method was applied to the protonation of thiophene and chlorothiophenes. The optimized structures and charge densities thus obtained are consistent with the experimental results obtained from the 1H NMR spectral data. In the neutral molecule, the β-chloro substituent lowers the total energy more than the α-one; however, the latter stabilizes the protonated state more than the former.
Manufacture of Pure Titanium(IV) Oxide by the Chloride Process. III. Precipitation of Hydrous Titanium(IV) Oxide in Hydrochloric Acid Solution at Elevated Temperatures
Authors: Narita Eiichi , Takeuchi Hitoshi , Horiguchi Naoto , Okabe Taijiro
Published: July 2006

Thermal hydrolysis of titanium(IV) in hydrochloric acid solutions (0.2 mol dm−3 in Ti(IV); 2 mol dm−3 in HCl) was carried out at temperatures up to 110 °C to investigate the effects of heating rate, heating temperature, aging time, and coexisting ions on the particle shape, size, crystal form, crystalline size, and content of water of the hydrous titanium(IV) oxide precipitated. The resulting polycrystalline particles having rutile structure were all distorted ellipsoids at the beginning of the hydrolysis, and gradually changed to spheres with rising temperature or with the duration of time. However, no effects of heating rate on the particle shape and size distribution were observed at the beginning of the hydrolysis. On the other hand, the precipitation rate of titanium(IV) measured at a constant temperature remarkably depended on the temperature; marked changes in the particle size distribution and mean particle size were observed during the reaction. The precipitation rate was well expressed by the rate equation based on the rate-determining step of the surface chemical reaction. The apparent activation energy was 111 kJ mol−1. Although no effects of coexisting cations such as iron(III) and aluminium(III) were recognized, the presence of sulfate and fluoride ions significantly affected the particle shape and size of such precipitates. Anatase-type hydrous titanium(IV) oxide consisting of spherical particles of narrow size distribution was also obtained in the presence of fluoride ion.
A Novel Synthesis of Azophenines
Authors: Merchant J R , Martyres Gail , Shinde N M
Published: July 2006

Aarylamines react with polyhaloalkanes in the presence of copper bronze to yield azophenines.
Stereoselective Formation of Rotaxanes Composed of Polymethylene-bridged Dinuclear Cobalt(III) Complexes and α-Cyclodextrin. II
Authors: Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

[2]-[[(en)2Co{XCH2S(CH2)nSCH2Y}Co(en)2]Clm]-[α-CDX]-rotaxanes (n=8, 10, and 12 for X=Y=CO2− (m=4); n=10 for X=CO2− and Y=CH2NH2(m=5); α-CDX=α-cyclodextrin) were prepared with partial stereoselectivity and characterized from their visible-UV absorption, circular dichroism(CD), and 13C NMR spectra, and elemental analysis. The rotaxane formation could be identified by the down field shift of the chemical shift due to α-CDX in the 13C NMR spectra and the increase of the CD intensity in the ligand-to-metal charge transfer band region in the CD spectra. The rotaxanes always showed apparently ΔΔ-rich CD spectra, the highest selectivity(10% ΔΔ-rich) being found in the case of n=10.
Extrinsic Carrier-photogeneration in Poly(N-vinylcarbazole)
Authors: Okamoto Ken-ichi , Itaya Akira
Published: July 2006

The carrier-photogeneration efficiency of holes in poly(N-vinylcarbazole) (PVCz) films was investigated by means of the time-of-flight method as a function of applied electric field, temperature, and excitation band. The extrinsic effects on the efficiency were examined; these included photooxidation of film surface and doping with a weak electron-acceptor, dimethyl terephthalate (DMTP). The experimental results were analyzed according to the Onsager theory of geminate recombination of a bound electron-hole pair with an interionic separation of ro. The primary yield of the electron-hole pair, φo, increased from 0.02 to 0.059 with decreasing excitation wavelength. By photooxidation, it increased up to 0.09 for all the excitation bands. The ro was independent of the excitation band, and was identical between fresh and photooxidized films. In DMTP(1.8 mol%)-doped films, both φo and ro were independent of the excitation band, although their values were different from those of undoped films. These results indicate that the extrinsic carrier-photogeneration via nonrelaxed exciplexes formed between singlet excitons and acceptor-like impurities or photooxidation products is predominant in PVCz films for all the excitation bands.
Synthesis of Several New Pyrazolo[5,1-c][1,2,4]triazoles, Imidazo[1,2-b]pyrazoles, and Pyrazolo[3,4-b]pyrazines. Reaction of Nitrilimines with Amino- and Oxo-substituted Azoles. II
Authors: Elgemeie Galal Eldin Hamza , Elfahham Hassan Attia , Ghozlan Said Ahmed Soliman , Elnagdi Mohamed Hilmy
Published: July 2006

The reactivity of amino and hydroxy azoles toward nitrilimines and hydrazonoyl halides was investigated. Several novel rotes for synthesis of derivatives of known heterocyclic systems are reported.
Determination of Solubility Products of Rare Earth Fluorides by Fluoride Ion-selective Electrode
Authors: Itoh Hisako , Hachiya Hiromitsu , Tsuchiya Masashi , Suzuki Yasuo , Asano Yasukazu
Published: July 2006

Solubility product values of the rare earth fluorides were determined potentiometrically by using fluoride ion-selective electrodes at 25.0 °C. The pKsp values of the lanthanoid fluorides decreased gradually from 20.0 to 16.9, while the value for yttrium fluoride was locate in between those of terbium and dysprosium fluorides. The value for scandium fluoride was appreciably smaller than any of the lanthanoid fluorides, as expected from the cationic radii. The solubility product value of lanthanum fluoride single crystal could not be determined, since the saturated solution was not obtained through measurements of over three months.
Hydrates of Organic Compounds. VIII. The Effect of Carboxylate Anions on the Formation of Clathrate Hydrates of Tetrabutylammonium Carboxylates
Authors: Nakayama Haruo , Torigata Shigeru
Published: July 2006

The solid-liquid phase diagrams of binary mixtures of tetrabutylammonium carboxylates, (n-C4H9)4 NOOCR (R=H-n-C10H21 including various alkyl groups replaced by either methyl or ethyl group), with water were examined in order to confirm the formation of clathrate-like hydrates. The results can be summarized as follows: (1) for 14 carboxylates the formation of a clathrate-like hydrate is newly confirmed; (2) judging from melting points and hydration numbers, the hydrates can be classified into three groups: I, II, and III; (3) the group I hydrates, formed by the carboxylates with R=H, CH3, C2H5, n-C3H7, i-C3H7, and t-C4H9, have hydration numbers around 30 and are the most stable hydrates among those examined in this experiment, with the exceptions of 2-methylpropionate and 2,2-dimethylpropionate hydrates; (4) the group II hydrates, with hydration numbers around 39, are formed by the salts with R=n-C4H9, s-C4H9, i-C4H9, and all the C5H11, and are relatively unstable (mp=5–11 °C); (5) the group III hydrates, with hydration numbers around 30 like the group I hydrates, are formed by the carboxylates with long alkyl chains from n-C6H13 to n-C10H21 and are generally unstable; and (6) judging from the hydration number, the crystal structure of the group I and III hydrates seems to be isomorphous with a tetrabutylammonium fluoride hydrate, and that of the group II hydrates with a tetrabutylammonium benzoate hydrate.
Pressure Effects on the Hydrolysis of Acetanilide Catalyzed by Cyclodextrins
Authors: Makimoto Syoichi , Suzuki Keizo , Taniguchi Yoshihiro
Published: July 2006

The rates of the hydrolysis of p-nitrotrifluoroacetanilide (pNFA) catalyzed by α- and β-cyclodextrins (α-, β-CD) were measured at pressures up to 2 kbar at 25 °C and at pH 6.9 in a 0.05 M Tris buffer solution. The substrate binding constants, K, and the rate constants of the acylation process, kacyl, increased monotonically up to 2 kbar. From the pressure dependence of K, the volume changes (ΔV) accompanying the formation of the inclusion complexes at 1 bar were −3±2 cm3/mol for α-CD–pNFA and −2±2 cm3/mol for β-CD–pNFA. The activation volumes (ΔV) for the cleavage of the anilide molecule in the acylation process were −25±2 cm3/mol for α-CD–pNFA and −18±2 cm3/mol for β-CD–pNFA. The reaction mechanisms of the cleavage of the anilide substrte by CDs were discussed on the basis of the volume parameters (ΔV and ΔV*).
Corrections for Intensity Data in Energy-dispersive X-Ray Diffractometry of Liquids. Application to Carbon Tetrachloride
Authors: Nishikawa Keiko , Iijima Takao
Published: July 2006

The procedure of the analysis of the diffraction intensity of liquids obtained by the energy-dispersive method has been revised and improved. A new method for determining the energy spectrum of the primary beam is presented. The escape correction, the slit correction and the correction for multiple scattering have been newly applied. Scattering of X-rays from liquid CCl4 has been measured and its structure function has been obtained by an improved procedure.
Photoelectron Angular Distribution and Assignment of Photoelectron Spectrum of Ozone
Authors: Katsumata Shunji , Shiromaru Haruo , Kimura Toshiaki
Published: July 2006

For the first three ionized states of ozone the ordering of 2A1, 2B2 and 2A2 states has so far been controversial both experimentally and theoretically. The present work establishes assignment of the 2A2 state by using the characteristic of electron energy dependence of an asymmetry parameter (β) of photoelectron angular distribution measured with NeI, HeI, and NeII resonance radiation. From measurements of photoelectron spectra of ozone with NeI, HeI, and HeII radiation, we newly find that two bands centered at 16.50 and 17.6 eV exhibit vibrational structures with the spacings of about 850 and about 1000 cm−1, respectively. Furthermore abnormally weak bands are also confirmed at 22.7, 24.1, and 26.8 eV in the Hell spectrum.
Ni(0)-Trialkylphosphine Complexes. Efficient Homo-coupling Catalyst for Aryl, Alkenyl, and Heteroaromatic Halides
Authors: Takagi Kentaro , Hayama Naomi , Sasaki Ken
Published: July 2006

Bis(trialkylphosphine)nickel(0) generated in situ from bis(trialkylphosphine)nickel(II) chloride was found to be an effective catalyst for a homo-coupling of aryl, alkenyl, or heteroaromatic halides with zinc powder. The catalytic reaction proceeded very well in NMP or HMPA solvent under mild conditions to afford dehalogenative-coupling products in good yields.
Syntheses of Polythia[n]ferrocenophanes and Polythia[n.n]ferrocenophanes. Marocyclic Polysulfide Ligands Containing a Ferrocene Nucleus
Authors: Sato Masaru , Tanaka Sinsuke , Ebine Seiji , Akabori Sadatoshi
Published: July 2006

1,1′-Bis(2-chloroethylthio)ferrocene reacted with disodium 1,2-ethanedithiolate to give 1,4,7,10-tetrathia[10]ferrocenophane and 1,4,7,10,22,25,28,31-octathia[10.10]ferrocenophane, along with unexpected 1,4,7-trithia[7]ferrocenophane, 1,4,7,10,13-pentathia[13]ferrocenophane and 1,4,7,10,13,25,28,31,34-nonathia[10.13]ferrocenophane. The reaction of 1,1′-bis(2-chloroethylthio)ferrocene with disodium 1,3-propanedithiolate gave 1,4,-8,11-tetrathia[11]ferrocneophane. 1,1′-Bis(3-chloropropylthio)ferrocene reacted with disodium 1,2-ethanedithiolate and 1,3-propanedithiolate to afford 1,5,8,12-tetrathia[12]ferrocenophane and 1,5,8,12,24,27,31,34-octathia[12.12]ferrocenophane, and 1,5,9,13-tetrathia[13]ferrocenophane, respectively. The structural features of the above polythia[n]ferrocenophanes are also discussed on the bases of their spectral data.
Effect of M-series PRBS Modulation on the Time Resolution in Correlation Photoacoustics
Authors: Sugitani Yoshinori , Uejima Akinori
Published: July 2006

Time resolution in the first kind correlation photoacoustics using the M-series PRBS mechanical light modulator was experimentally checked. It was found that the time resolution limited by the mechanical chopper was more determinative than that by the microphone detector or the time delay unit in the experimental system used.
The Reactions of Nitrile Oxides with Methoxy p-Benzoquinones
Authors: Hayakawa Tohru , Araki Koji , Shiraishi Shinsaku
Published: July 2006

The 1,3-dipolar cycloaddition reactions of nitrile oxides with methoxy p-benzoquinones are discussed in terms of FMO theory. The unusual reaction pattern of methoxy p-benzoquinones with nitrile oxides is interpreted by considering both antibonding secondary orbital interaction and SHOMO(quinone)–LUMO (nitrile oxide) interaction.
A Convenient Synthesis of 2-Acylmethyl-4,4-dimethyl-2-oxazolines. Useful Reagents for β-Keto Ester Synthesis
Authors: Tohda Yasuo , Kawashima Toshihide , Ariga Masahiro , Akiyama Ryohei , Shudoh Hiroshi , Mori Yutaka
Published: July 2006

Acylation of 2,4,4-trimethyl-2-oxazoline with acid chlorides having no α-proton and triethylamine gave C,N-diacylated products. Hydrolysis of the products with potassium hydroxide gave the enols of 2-acylmethyl-oxazolines, which were selectively C-monoalkylated by alkyl halides.
Tetrakis[3,5-bis(trifluoromethyl)phenyl]borate. Highly Lipophilic Stable Anionic Agent for Solvent-extraction of Cations
Authors: Nishida Hiroshi , Takada Naoko , Yoshimura Masaji , Sonoda Takaaki , Kobayashi Hiroshi
Published: July 2006

Tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB) anion was highly lipophilic, practically insoluble in water, and durable against acid and oxidants. Partition equilibria of alkali TFPB between water and organic solvents and the stability in acid media are described and compared with the properties of the parent tetraphenylborate and of some fluorine-containing homologues.
Preparation of 5-Substituted-2-pyrrolin-4-ones from N-(4-Oxo-2-pyrrolin-5-yl)sulfoximines
Authors: Yoshida Hiroshi , Bando Shoichi , Nakajima Shosuke , Ogata Tsuyoshi , Matsumoto Kiyoshi
Published: July 2006

In trifluoroacetic acid, immonium cations were generated from S,S-dimethylsulfoximines in which the pyrrolinone ring was substituted. Nucleophiles such as alcohols, thiocyanic acid, thiols, or acetylacetone reacted with the immonium salts to yield 5-substituted 2-pyrrolin-4-ones.
Oxidation of 2,6-Bis(hydroxymethyl)phenols to 2-Hydroxyisophthalaldehydes by MnO2
Authors: Taniguchi Shozo
Published: July 2006

A facile and direct preparative method of 2-hydroxyisophthalaldehydes from 2,6-bis(hydroxymethyl) phenols using activated manganese(IV) oxide is described. The aldehydes are obtained in good yields.
Regio- and Stereocontrolled Synthesis of Allenic and Acetylenic Derivatives. Organotitanium and Boron Reagents
Authors: Furuta Kyoji , Ishiguro Masaharu , Haruta Ryuichi , Ikeda Nobuo , Yamamoto Hisashi
Published: July 2006

The propargyltitanium reagents derived from 1-alkylpropyne condensed with aldehydes to give α-allenyl alcohol regioselectively, while the allenyltitanium reagents generated from 1-alky1-1-butyne derivatives gave threo-β-acetylenic alcohols with high regio- and stereoselectivities. The course of the reaction was determined by the substitution pattern of starting alkynes. The similar reactions of metallated 1,3-bis(trialkylsilyl)propyne or (trialkylsilyl)acetonitrile with aldehydes were also investigated.
Structure Determination of Bitter Principles of Ailanthus altissima. Structures of Shinjulactones F, I, J, and K
Authors: Ishibashi Masami , Yoshimura Shin , Tsuyuki Takahiko , Takahashi Takeyoshi , Itai Akiko , Iitaka Yoichi
Published: July 2006

Four new quassinoids, shinjulactones F, I, J, and K were isolated from Ailanthus altissima  Swingle. The structure of shinjulactone F was established to be 1α,11-epoxy-1β,20-dihydroxy-5βH-picrasa-3,9(11)-diene-2,12,16-trione by X-ray diffraction analysis. The structures of shinjulactones I, J, and K were determined to be 11α-acetoxy-2α, 12α-dihydroxypicrasane-1,16-dione, 1β,12β-dihydroxypicrasane-2,11,16-trione, and 12α-acetoxy-2α,11α-dihydroxypicrasane-1,16-dione, respectively, by spectral and chemical means.
A New Synthesis of Pyrazolo[3,4-b]quinoline Derivatives
Authors: Holla D C , Seshadri S
Published: July 2006

A new synthesis of pyrazolo[3,4-b]quinoline-4-carboxylic acid derivatives is described. This involves the Pfitzinger reaction of pyrazolone derivatives with isatic acid under controlled conditions. The pyrazoloquinolinecarboxylic acids were converted to their corresponding amides and nitriles, and their absorption and emission characteristics are recorded.
Fluorescence of Europium Tris(bromate) Enneahydrate with Ar+ Laser Excitation
Authors: Hasunuma Masahiko , Okada Keiko , Kato Yoshifumi
Published: July 2006

The (f,f*) transitions of europium tris(bromate) enneahydrate crystal between 12000 and 20000 cm−1 were measured at 95 K by laser-excited fluorescence spectroscopy. The crystal field components of the ground (7F0.1···6) and the excited states (5D0.1) participating in the transitions were analyzed in terms of the tensor-operator method. Besides electric-dipole transitions, a number of magnetic-dipole transitions were detected in compliance with the selection rule. The theory could reproduce the observed wavenumbers and intensities both for the σ- and π-transitions. The population ratio of the 5D0 to the 5D1 was estimated to be 14.1 from the intensity calculations and the observed results. The result suggests that mixing of g-orbitals is significant for the forced electric-dipole transitions.
Structural Characterization of Several Metal(II) 2-Methyl-8-quinolinolato Complexes in Several Organic Solvents
Authors: Nariai Hiroyuki , Masuda Yoshitaka , Sekido Eiichi
Published: July 2006

Bivalent metal complexes of cobalt(II), nickel(II), copper(II), and zinc(II) with 2-methyl-8-quinolinol (2MeHql) were prepared. Their properties, such as those shown by thermogravimetry (TG) and differential thermal analysis (DTA), X-ray diffraction, magnetic susceptibility, and the optical spectra, were measured and compared with those of 8-quinolinolato complexes. All the metal complexes prepared here are monohydrates, whereas their 8-quinolinolato complexes are dihydrates. The methyl group at the 2-position of the quinoline ring caused a shift of about 40–80 °C in the dehydration temperature, and, as a result of the dehydration, a dimer anhydrate was produced. The dimer-formation conditions were established in chloroform and dioxane solutions. However, the addition of such basic solvents as pyridine, water, and methanol cleaved the bridge linkages in complexes and produced a distorted octahedral configuration by solvent-binding in the axial position. The existence of a copper complex with a dimer structure such as has been shown in other metal complexes was not verified in any of the solvents used here.
Stability Constants of Some Bivalent Metal Chelates of 3-Aryl-2,4-pentanedione in 75% v/v 1,4-Dioxane-Water Medium
Authors: Wakui Yoshito , Yano Katsunori , Nakano Yoshiharu , Ohashi Kousaburo , Yamamoto Katsumi
Published: July 2006

A new ligand, 3-(1-naphthyl)-2,4-pentanedione, was prepared. Concentration proton-dissociation constants of 3-aryl-2,4-pentanedione (aryl group; phenyl, 2,4-dinitrophenyl, and 1-naphthyl) and concentration stability constants of some bivalent metal chelates of 3-aryl-2,4-pentanedione were determined in a 75% v/v 1,4-dioxane–water medium containing 0.05 mol dm−3 sodium perchlorate by a pH-titrimetric method. The dissociation constant (pKa) of 3-(2,4-dinitrophenyl)-2,4-pentanedione, 2,4-pentanedione, 3-phenyl-2,4-pentanedione, and 3-(1-naphthyl)-2,4-pentanedione were found to be 8.87, 10.93, 11.50, and 11.71, respectively. The order of acidity in 2,4-pentanedione was explained by the field effect of the aryl group. The stability constants of the bivalent metal chelates of these ligands were in accord with the Irving-Williams series. The stepwise stability constant of the chelate increased with an increasing pKa value of 3-aryl-2,4-pentanedione. This result cannot be explained by the steric and solvation effect of an aryl substituent.
Studies on N-Glycopeptides. II. Separation of α- and β-Amide of N-(l-Aspartyl)-β-d-glucopyranosylamine Obtained via N-(Benzyloxycarbonyl)-l-aspartic Anhydride
Authors: Tamura Masahiro , Nishizaki Hiroshi , Miyazaki Chiemi , Okai Hideo
Published: July 2006

A mixture of N-(l-α-aspartyl)- and N-(l-β-aspartyl)-β-d-glucopyranosylamine was obtained by the condensation of N-(benzyloxycarbonyl)-l-aspartic anhydride with β-d-glucopyranosylamine. Attempts to separate the mixture by using cation-exchange chromatography, a copper(II) complex, and fractional recrystallization were carried out. These separations gave good yields of the desired β-amine.