bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Reaction Mechanism of 2-Dimethoxymethyl-3-methoxypropionitrile with Acetamidine. II. A Novel Reaction Pathway
Authors: Nishino Takenori , Kiyokawa Masumi , Miichi Yoshiyuki , Tokuyama Kanji 
Published: July 2006

Abstract
The reaction of 2-dimethoxymethyl-3-methoxypropionitrile (1) with acetamidine produces pyrimidopyrimidine (8) via the consecutive process of 1→an intermediate→8. The intermediate was not isolated, but two structures have been proposed for it. We have now succeeded in the isolation of the intermediate and determined it to be 2-methyl-4-amino-5-dimethoxymethyl-5,6-dihydropyrimidine (4). Several key intermediates were also successfully isolated. The novel reaction pathway for the title reaction was concluded to be as follows: the elimination of methanol from 1, followed by the addition of acetamidine affords 3-acetamidinopropionitrile (3), the subsequent quick cyclization of which produces the intermediate, 4; the further elimination of methanol from 4, followed by a replacement reaction with acetamidine, gives an acetamidinomethylene compound (6), which is converted into the final product, 8, via an intermediate (7). Some minor pathways will also be presented.
The Reaction of Aspartyl Dipeptide Esters with Ketones
Authors: Ariyoshi Yasuo , Sato Naotake 
Published: July 2006

Abstract
The methyl and ethyl esters of α-l-aspartyl-l-phenylalanine (I and II), -l-tyrosine (III and IV), -l-(β-cyclohexyl)alanine (V and VI), and -l-[β-(4-hydroxycyclohexyl)]alanine (VII and VIII) have been found to react with ketones (acetone, methyl ethyl ketone, and cyclohexanone), in the absence of any catalysts, to give the corresponding 4-imidazolidinone derivatives (XVII–XXX). The NMR spectra of the imidazolidinones with an aromatic side chain (XVII–XXVIII) have indicated that these compounds exist in the folded conformation (in which the aromatic ring faces the imidazolidinone ring) in the solution. The imidazolidinones (XVII–XXX) were hydrolyzed with hot water to give the peptide esters (I–VIII), all in their original optical purity. On the other hand, the β-isomers of the peptide esters (IX–XVI) did not react with these ketones under the same conditions. These characteristics were used successfully in the separation of the two structural isomers of these peptide esters.
The Reaction of Sulfilimine with Phenyl Grignard Reagent
Authors: Oae Shigeru , Yoshimura Toshiaki , Furukawa Naomichi 
Published: July 2006

Abstract
The reactions of diphenyl (I), phenyl benzyl (II), and phenyl methyl N-p-tosylsulfilimines (III) with phenylmagnesium bromide were carried out. (I) gave biphenyl and diphenyl sulfide in high yields. A tracer experiment with diphenyl sulfilimine-1-14C revealed that the reaction proceeds via the initial formation of triphenylsulfonium salt upon which the attack of phenylmagnesium bromide affords the products. “Benzyne” mechanism is ruled out. (II) and (III) gave various compounds, the major products being α-phenylated sulfides which are presumed to be formed by the Pummerer type rearrangement initiated by the abstraction of α-proton by the Grignard reagent.
Reaction of α-Chloro Sulfoxides with Carbonyl and Thiocarbonyl Compounds
Authors: Tsuchihashi Gen-ichi , Ogura Katsuyuki 
Published: July 2006

Abstract
Ghloromethyl methyl sulfoxide undergoes a Darzens-type reaction with carbonyl compounds in the presence of potassium t-butoxide in t-butanol to afford methylsulfinyloxirane derivatives. The stereochemistry of this reaction has been studied. The reaction with a symmetrical ketone appeared to proceed stereospecifically to give only one isomer. On the other hand, the reaction with unsymmetrical ketones such as pinacolone or acetophenone produced a mixture of two diastereoisomers, in which a thermodynamically unstable isomer was predominant. The reaction with thiobenzophenone gave 1,1-diphenyl-2-methylsulfinylethylene which seems to have been formed from the intermediacy of 2,2-diphenyl-3-methylsulfinylthiirane. Mechanisms of these reactions are also discussed.
Aminosugars. XX. Synthesis of Some Derivatives of 2-Acetamido-2-deoxy-d-mannose
Authors: Yoshimura Juji , Sakai Hideo , Oda Nobuteru , Hashimoto Hironobu 
Published: July 2006

Abstract
Preparation of 2-acetamido-2-deoxy-d-mannose (2) by epimerization of the corresponding d-glucose was improved by addition of Ni2+ ion to the equilibration system, and several derivatives of (2) were synthesized. N-glycosides were obtained by using ammonium chloride as a catalyst, and p-nitrophenyl glycoside by a fusion method. The composition of four isomers in benzylglycosidation of (2) was determined to be 66% α-pyranoside (6), 11% β-pyranoside, 16% α-furanoside (5) and 7% β-furanoside. Benzylidenation of 6 gave the corresponding 4,6-O-benzylidene derivative which was converted into the 3-O-acetate (8) by acetylation, and to the corresponding 2-amino-2-deoxy derivative by treatment with ethanolic potassium hydroxide. Oxidation of 6 with oxygen in the presence of platinum-charcoal and following esterification gave the corresponding methyl uronate which was derived to the di-O-acetate (11). Periodate oxidation and the following hydrogenation of 5 gave benzyl 2-acetamido-2-deoxy-α-d-lyxofuranoside which was then derived to di-O-acetate (13). Nitromethane condensation of 2 in barium hydroxide solution gave one isomeric 1-C-nitro-1-deoxy-d-heptitol which was converted into methyl 3-acetamido-3-deoxy-d-gaycero-d-galacto-α-heptopyranoside (18). First-order analyses of NMR spectra of 8, 11, 13, and tetra-O-acetate of 18 are described.
Cationic Arylation. V. Reaction of Substituted Benzenes with p-Nitrophenyl Cation
Authors: Kamigata Nobumasa , Kobayashi Michio , Minato Hiroshi 
Published: July 2006

Abstract
The cationic arylation of substituted benzenes was investigated with p-nitrophenyl cation generated from p-nitrobenzenediazonium tetrafluoroborate in acetonitrile and from p-nitrophenylazo p′-tolyl sulfone in the presence of trifluoroacetic acid. The isomer distribution of substituted nitrobiphenyls produced and the partial rate factors indicated electrophilic character of the p-nitrophenyl cation. Selectivity of p-nitrophenyl cation is low compared with those of nitronium or sulfonyl cation, and similar to that of phenyl cation. These facts suggest that the p-nitrophenyl cation functions as a cation diradical with concerted uncoupling of a pair of π-electrons, one of which falls into the vacant sp2 σ-orbital.
The Migratory Aptitudes in the 1,3-Dipolar Cycloadducts of Substitiuted 1-Benzoyliminopyridinium Ylides with Dimethyl Acetylenedicarboxylate
Authors: Sasaki Tadashi , Kanematsu Ken , Kakehi Akikazu , Ito Gin-ichi 
Published: July 2006

Abstract
The 1,3-dipolar cycloaddition of substituted 1-benzoyliminopyridinium ylides (1, 6, and 9) with dimethyl acetylenedicarboxylate (DAG) produced the corresponding rearrangement compounds (3, 4, 7, 8, and 10). On the other hand, the similar reaction of 11 with DAC in acetonitrile gave 12, accompanied with a Sommelet-type rearrangement compound, 13. The structural elucidation of these products was accomplished by spectral inspections.
Stereochemical Studies of Monoterpene Compounds. XVIII. A Conformational Study of Monoterpene α,β-Unsaturated Ketones by Means of the Temperature-dependent Circular Dichroism
Authors: Suga Takayuki , Imamura Kiyoshi 
Published: July 2006

Abstract
The conformations of flexible, cyclic α,β-unsaturated ketones, (−)-p-menth-3-en-5-one (1), (+)-carvone (2), (−)-piperitone (3), (−)-carvenone (4), and (+)-pulegone (5), were examined by means of the temperature-dependent circular dichroism (CD) in the region of the n-π* transition. In polar solvents, the simultaneous occurrence of the conformational equilibrium and the asymmetric solvation was observed markedly for the compound 1 of these compounds, along with a change in the large rotational strength at lower temperatures.
The Diffusion of Gases at High Pressures. IV. The Diffusion of CTH3 in the CH4-CO2 System
Authors: Takahashi Shinji 
Published: July 2006

Abstract
The diffusion coefficients of radioactive methane (CTH3) in normal methane, in carbon dioxide, and in a mixture of normal methane with carbon dioxide (0.522 mol fraction of methane) were measured at the temperatures of 25, 50, and 75°C in the 15–250 atm pressure range. The measurements were made through a plug of porous bronze in the diffusion cell, using the radioactive tracer technique. The diffusion coefficient-density products, Dρ, for the CTH3–normal methane system and the CTH3- the binary mixture system increased slightly with an increase in the density in the lower-density region at 25 and 50°C, but they were nearly constant at 75°C. The Dρ for the CTH3–carbon dioxide system decreased with an increase in the density at each temperature. The Dρ-values at 1 atm, obtained by extrapolation, agreed fairly well with those reported in the literature. The density dependence of the Dρ values at high densities could not be predicted by Enskog-Thorne’s theory.
Catalytic Properties of BF3-treated Aluminas. IV. The Effect of BF3 Adsorption on the Acidic Properties of Aluminum Oxides
Authors: Matsuura Kanjiro , Suzuki Akira , Itoh Mitsuomi 
Published: July 2006

Abstract
An account was given of the surface acidic properties of a series of BF3-treated aluminum oxides, ranging in their precalcination temperature up to 1000°C. It was concluded that all aluminum oxides dehydrated over 300°C were converted to solid acids with new strong acid centers of H0≤−8.2 by adsorption with BF3. This new acid centers would be certainly of the Brönsted type. Their catalytic activities in some carbonium ion type reactions are well correlated with the n-butylamine acidity in the presence of Hammett’s indicators, and the maximum number of acid centers was observed in catalyst samples precalcined at 450 and 800°C respectively. The present study also suggests that the acid centers developed on the surface of aluminum oxides are somewhat different in nature depending upon their precalcination temperatures. Since there was a good correlation between the amount of the remaining hydroxyl groups and that of the absorbed BF3, the surface hydroxyl groups, in addition to the aluminum atoms serving as the Lewis centers, which are not fully coordinated, were discussed as the most important factors in the formation of such acid centers.
Studies of the Synthesis of Furan Compounds. XXVI. The Reaction of 5-Nitro-2-furimidoylhydrazine with Acid Anhydrides
Authors: Hirao Ichiro , Kato Yasuhiko , Tateishi Hiromichi 
Published: July 2006

Abstract
Reactions between 5-nitro-2-furimidoylhydrazine (I) and acetic or propionic anhydride (or the corresponding acids) under various conditions afforded 5-methyl- (II) and 5-ethyl-2-(5-nitro-2-furyl)-1,3,4-oxadiazole (IV) and 5-methyl- (III), 5-ethyl- (IX), 1 -acetyl-5-methyl- (VII), 1-propionyl-5-ethyl- (VIII), 1-propionyl-5-methyl- (X), and 1-acetyl-5-ethyl-3-(5-nitro-2-furyl)-1,2,4-triazole (XI) respectively. The treatment of I with acetic and propionic anhydride in refluxing benzene or tetrahydrofuran gave 1-acetyl- (V) and 1-propionyl-2-(5-nitro-2-furimidoyl)-hydrazine (VI) respectively. Compounds, VII, VIII, X, and XI were also prepared by the cyclization of V with propionic anhydride and by that of VI with acetic anhydride in dioxane. The structures of the products were discussed on the basis of the spectral data.
Ultrasonic Absorption in Solutions of Propionic Acid
Authors: Tatsumoto Nobuhide , Sano Takayuki , Matsunaga Norihiko , Tochigi Eiso , Yasunaga Tatsuya 
Published: July 2006

Abstract
The effect of a solvent on the ultrasonic relaxation of propionic acid has been studied. The relaxation frequency is affected a little in hydrophilic solvents, while in non-hydrophilic solvents it shifts to a higher-frequency side. The activation enthalpy in a reaction from open to cyclic dimers decreases with dilution in the non-hydrophilic solvents; the magnitude of the change in the hydrophilic solvents is less than in the non-hydrophilic solvents. This means that the open dimer is destabilized by non-hydrophilic solvents. The sequence of the magnitude of the solvent effect on the relaxation frequency is consistent not with that estimated from the magnitude of the dielectric constant of the solvent, but with that estimated from the magnitude of the non-hydrophilic strength of the solvent. The stability of an open dimer in a hydrophilic or polar solvent is attributed to the interaction of the free OH group on the open dimer with the solvent.
An Isothermal Displacement Calorimeter for Measuring Enthalpies of Mixing
Authors: Tanaka Reiji , Murakami Sachio , Fujishiro Ryoichi 
Published: July 2006

Abstract
An isothermal displacement calorimeter of the Van Ness type has been constructed. The calorimeter was tested on three systems, benzene+cyclohexane, cyclohexane+n-hexane, and benzene+dichloromethane, at 25°C, and the performance of the calorimeter was discussed in connection with the literature values. The precision of the new calorimeter was within 0.5%; this was equal to, or better than, that of calorimeters of a similar type which have been constructed by several investigators.
The Reaction of Mono-, Di-, and Trisodium Orthophosphate in a Mixed Solution of Acetic Acid and Acetic Anhydride
Authors: Watanabe Makoto , Senda Tetsushi 
Published: July 2006

Abstract
Mono-, di-, or trisodium orthophosphate was heated at 100°C in an equivolume mixture of acetic acid and its anhydride. By X-ray diffractometry and paper chromatography, the products from these three sodium salts of orthophosphate were found to be sodium trimetaphosphate. At the end of the 30-hr reaction period, the purity of the trimetaphosphate was higher than 90%. The ease of formation of the trimetaphosphate ring under various conditions was shown, and the stability of the ring was discussed on the basis of the strain of the bonding angle.
Syntheses of 1,2-Dithiole Derivatives
Authors: Chinone Akiko , Inouye Kozo , Ohta Masaki 
Published: July 2006

Abstract
Sulfurization of 1,3-diarylpropanetrione (1) with hydrogen sulfide and hydrogen chloride afforded a mixture of 4-hydroxy-3,5-diaryl-1,2-dithiolium chlorides (3) and 3,5-diaryl-1,2-dithiolium chlorides (4). Treatment of a mixture of 3a and 4a with triethylamine in alcohol gave anhydro-4-hydroxy-3,5-diphenyl-1,2-dithiolium hydroxide (5a) and the 4-substituted product (6). Sulfurization of dibenzoyldibromomethane yielded 3,5-diphenyl-1,2-dithiolium bromide. Reactions of 5a with picric acid and acetic anhydride in the presence of perchloric acid were carried out.
Synthesis and Properties of Metal Complexes with a New Multidentate Schiff Base Containing Ethereal Oxygen Atoms
Authors: Murase Ichiro , Yamanouchi Kuniko , Yamada Shoichiro 
Published: July 2006

Abstract
A new multidentate Schiff base, 1,4-bis(o-salicylideneaminophenyl)-1,4-dioxabutane having six atoms which may be available for bonding with a metal ion was prepared. With this ligand several metal complexes have been synthesized. From their magnetic properties, electronic absorption spectra and X-ray powder diagrams, it has been concluded that the cobalt(II), nickel(II), and zinc(II) complexes are isomorphous, having a five coordinated configuration, in which one of the ethereal oxygen atoms of the ligand is bound with the metal ion. The copper(II) complex with a similar composition has a different configuration.
Six-coordinate Chromium(III) Complexes with N,N′-Ethylene-bis(acetylacetoneiminate) as a Ligand
Authors: Yamanouchi(Formerly Iwasaki) Katsumoto , Yamada Shoichiro 
Published: July 2006

Abstract
Numerous six-coordinate chromium(III) complexes with N,N′-ethylene-bis(acetylacetoneiminate) (abbreviated as Acen) have been synthesized. The complexes obtained are of the type [Cr(Acen)X2]Y, where X=H2O, NH3, CH3NH2, n-C3H7NH2, and n-C4H9NH2 for Y=Cl and X=CN, NCS, and NO2 for Y=K. The complex [Cr(Acen)(H2O)2]Cl has been obtained by a reaction of anhydrous chromium(III) chloride with N,N′-ethylene-bis(acetylacetoneimine) in tetrahydrofuran. The other complexes have been derived from the diaquo-complex. Infrared spectra show that the nitrite ions in [Cr(NO2)2(Acen)]− and the thiocyanate ions in [Cr(NCS)2(Acen)]− are bound with the chromium(III) ion through oxygen and nitrogen atoms, respectively. Electronic absorption bands of all these complexes, which arise from internal transitions within the ligand Acen, differ greatly from those of the free ligand, suggesting that the electronic states of the ligand in the complexes differ from those of the free ligand.
Cobalt(I) Tetraphenylporphin
Authors: Kobayashi Hiroshi , Hara Tetsuo , Kaizu Youkoh 
Published: July 2006

Abstract
Cobalt(I) tetraphenylporphin was prepared by reduction of tetraphenylporphinatocobalt(II) with sodium benzophenone ketyl in tetrahydrofuran (THF) and was purely isolated. The compound was identified as Na-[Co(I)TPP]·5THF (tetraphenylporphin is abbreviated to TPP). On the basis of electronic absorption spectrum, magnetic circular dichroism, magnetic susceptibility and NMR spectrum, the complex formed was concluded to be a complex of cobalt(I). Although some part of cobalt electron is migrated into the conjugated system of porphin, an electron furnished by the reducing reagent is mainly trapped by the central cobalt. The compound should be named sodium tetraphenylporphinatocobaltate(I).
Electronic Absorption Spectra of Tris(2,2′-bipyridine)- and Tris(1,10-phenanthroline) Complexes of Vanadium(II) and Chromium(II)
Authors: Fujita Ichiro , Yazaki Takanori , Torii Yasuo , Kobayashi Hiroshi 
Published: July 2006

Abstract
Electronic absorption spectra of tris(2,2′-bipyridine) complexes of vanadium(II) and chromium(II) were measured. When methyl groups are introduced into the coordinating bipyridine, (d, d*) transitions in the central metal, (π, π*) transitions in the coordinating ligand, and “metal to ligand” charge-transfer transitions show their respective characteristic shifts. Thus the visible and near-infrared bands of tris(2,2′-bipyridine) complexes of vanadium(II) and chromium(II) are assigned to “metal to ligand” charge-transfer transitions as well as the visible bands of tris(2,2′-bipyridine)iron(II). A comparison between the corresponding bands of tris(2,2′-bipyridine) complexes and tris (1,10-phenathroline) complexes also verifies the assignment.
Polarographic Study of the Rates of the Dissociation Reactions of the Nickel(II)-, Zinc(II)-, and Cadmium(II)-2,2′-Ethylenedioxybis[ethyliminodi(acetate)] (GEDTA) Complexes
Authors: Kodama Mutsuo , Oyama Noboru 
Published: July 2006

Abstract
In GEDTA solutions with pH’s lower than 7.00, the nickel(II), zinc(II), and cadmium(II) ions were found to yield the one-step, two-step, and three-step polarographic waves respectively. The polarographic wave of the nickel(II) ion, the first step of the zinc(II) ion, and the first and second steps of the cadmium(II) ion showed a kinetic-controlled nature. In this study, the polarographic wave of the nickel(II) ion, the first step of the zinc(II) ion, and the second step of cadmium (II) ion were studied systematically. From an experimental examination of the nature of the kinetic currents of these complexes, the mechanisms for the above polarographic steps were determined as:
(Remark: Graphics omitted.)
where CdHY−* is the electroactive cadmium(II)-GEDTA complex. By comparing the dissociation rate constant of the nickel(II)-GEDTA complex with that of the nickel(II)-aspartate complex, the detailed dissociation mechanism was determined. The rates and mechanisms of the dissociations of zinc(II) and cadmium(II)-GEDTA complexes were also discussed in detail.
Phytosterols and Triterpenes in the Roots of the “Kidney Bean” (Phaseolus vulgaris L.)
Authors: Katsui Nobukatsu , Matsue Hajime , Hirata Tomohiko , Masamune Tadashi 
Published: July 2006

Abstract
In connection with the studies of hatching substances for soybean cyst nematodes, the neutral fraction of the roots of the “kidney bean” (Phaseolus vulgaris L.) has been examined. It was found that phytosterols and triterpenes exist in the roots of plants.
The Bromine Nuclear Quadrupole Resonance of the Molecular Complex of Aluminum Tribromide with Benzene
Authors: Okuda Tsutomu , Furukawa Yoshihiro , Negita Hisao 
Published: July 2006

Abstract
The bromine nuclear quadrupole resonance (NQR) and its Zeeman effect have been observed in the molecular complex of aluminum tribromide with benzene at room temperature. The resonance frequencies are 79.99, 90.10, and 91.18 MHz for 81Br at 301°K. The asymmetry parameters of the field gradient are 28.9±1.1, 8.6±1.0, and 6.0±0.9% for the bromine atoms in the order of increasing resonance frequency. Aluminum tribromide forms the dimer in the complex crystal as well as in the pure state. The bond angle between a pair of terminal bromine atoms and the interbond angle at the bridging bromine atom are found to be 117.3±0.5° and 95.5±0.2° respectively; these values correspond to those of 122±2° and 87±2° obtained from the X-ray analysis. Furthermore, the charge-transfer from the benzene ring to the bromine atom is discussed on the basis of the NQR parameters.
On the Emission Spectra of the Unimolecular Reaction of Methylamine by Electron Impact
Authors: Fukui Kiyoshi , Fujita Iwao , Kuwata Keiji 
Published: July 2006

Abstract
The emission spectra of the following excited species produced from methylamine by electron impact (the energy of 150 eV) at a low pressure were observed: NH(A3Π–X3Σ), CN(B2Σ–X2Σ), CH(A2Δ–X2Π), and H(Balmer series). It was confirmed that the excited species are produced by a unimolecular reaction of methylamine. The replacement by deuterium decreases the production of the excited hydrogen atom from methylamine by about 40%, this supports the idea that the excited hydrogen atom is produced through a superexcited state of methylamine. It was also determined that the production of the excited hydrogen atom of the methyl group was less than that of the amino group by about 20%. This is in contrast to the findings on the mass spectrum of CD3NH2, where the peak of CD2NH2+ was much higher than that of CD3NH+. The NH radical in the A3Π state was produced from methylamine and dimethylamine, while the NH radicals in the A3Π and the c1Π states were produced from ammonia.
Kinetic Study of the Formation and Decomposition of Amylose-iodine-iodide Complex
Authors: Yamagishi Akihiko , Imamura Taira , Fujimoto Masatoshi 
Published: July 2006

Abstract
The complex formation reaction among amylose, iodine and iodide ion in aqueous solution was investigated with a stopped-flow apparatus. The forward reaction rate was found to be expressed as v=k[Amylose]([I3−]–θ) for [I3−]&gt;θ, where θ is a critical value determining the mechanism. For [I3−]&gt;θ, the rate was considered to be determined by the process between a free amylose unit and free I3−. For [I3−]&lt;θ, the rate-determining step is considered to be intramolecular conversion from an intermediate to a final product. The rate of the reaction between amylose units and I3− is close to that of a diffusion-controlled process (7×108 m−1 sec−1). These conclusions are supported by the study of the decomposition reaction of complex, using Na2S2O3 or Ce(SO4)2.
Energy Transfer in the γ-Irradiated Benzene Solutions of Carbonyl Sulfide, Nitrous Oxide, and Carbon Dioxide
Authors: Sato Shin , Hosoya Kiyoshi , Shishido Seishi , Hirokami Shun-ichi 
Published: July 2006

Abstract
The γ-radiolysis of benzene solutions containing carbonyl sulfide, nitrous oxide, and carbon dioxide has been investigated at room temperature and at 0°C. Carbonyl sulfide was shown to be an effective electron scavenger and to give carbon monoxide as the product. By comparing the solute concentration dependences of G(N2) and G(CO), it was concluded that the collision of secondary electrons with benzene does not efficiently produce the first excited singlet state, the G-value of which is less than 0.2 if it is produced at all. The concentration dependences of the G(CO) and G(phenol) from the benzene solution of carbon dioxide also suggested that the superexcited state or the highly-excited state of benzene is too short-lived to transfer its energy to the solute.