bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Polarized Absorption Spectra of Some β-Substituted Anthraquinones
Authors: Inoue Hiroyasu , Hoshi Toshihiko , Yoshino Junko , Tanizaki Yoshie 
Published: July 2006

Abstract
The polarized absorption spectra of 2-hydroxy-, 2-amino-, and 2,3-diaminoanthraquinones were measured in stretched PVA sheets below 47 kK, and semiempirical ASMO-SCF-CI calculations, including the variable β method, were carried out for these compounds. By a comparison of the observed and the calculated results, the π–π* bands of these compounds were assigned. Each of these compounds has six bands in the observed wave number region, four of which correspond to those of anthraquinone; the other two bands can be assigned to the intramolecular charge-transfer transitions.
Synthesis of Anomeric Methyl 6-O-(l-Mycarosyl)-β-d-glucosaminides and 4-O-(l-Mycarosyl)-β-d-mycaminosides
Authors: Koto Shinkiti , Yago Kazuo , Zen Shonosuke , Omura Satoshi 
Published: July 2006

Abstract
Condensation of 3,4-O-carbonyl-2,6-dideoxy-3-C-methyl-l-ribohexopyranosyl chloride (III) with methyl 2-deoxy-2-(2,4-dinitroanilino)-β-d-glucopyranoside and the subsequent removal of blocking groups gave the anomeric isomers of methyl 6-O-(2,6-dideoxy-3-C-methyl-l-ribohexopyranosyl)-2-amino-2-deoxy-β-d-glucopy-ranoside (VIIa, VIIb). On the other hand, the condensation of III with methyl 3,6-dideoxy-3-(N-methylcarboethoxyamino)-2-O-p-phenylazobenzoyl-β-d-glucopyranoside (XI) followed by removal of the acyl groups and N-methylation afforded the anomeric forms of methyl 4-O-(2,6-dideoxy-3-C-methyl-l-ribohexopyranosyl)-3,6-dideoxy-3-dimethylamino-β-d-glucopyranoside (XVa, XVb).
Photochemical Rearrangement of 2-Nitrophenyl Phenyl Sulfoxide to 2-Nitrosophenyl Phenyl Sulfone
Authors: Tanikaga Rikuhei , Kaji Aritsune 
Published: July 2006

Abstract
Irradiation of 2-nitrophenyl phenyl sulfoxide (I) gave 2-nitrosophenyl phenyl sulfone (II) as the sole product. The rearrangement was not affected by a quencher, but took a different course in the presence of a sensitizer or a halogen-containing solvent. When I with an electron-donating substituent at a 4′-position or electron-withdrawing one at a 4-position was irradiated, the corresponding II was obtained in a lower yield. 2-Nitrophenyl phenyl sulfide was photochemically stable. From the results, it is proposed that in the excited singlet state of I the oxyanion of a nitro group attacks the positive sulfur atom, and oxygen transfer takes place.
Behavior of 2-Pyrazolin-5-ones toward Activated Double Bond Systems: Cyanoethylation of 2-Pyrazolin-5-ones
Authors: Elnagdi Mohamed Helmi , Ohta Masaki 
Published: July 2006

Abstract
3-Methyl-2-pyrazolin-5-one(Ia) reacts with acrylonitrile to yield either 4,4-di(β-cyanoethyl)-5-hydroxy-3-methylpyrazole(IV) or 1,4,4-tri(β-cyanoethyl)-3-methyl-2-pyrazolin-5-one(V) depending on the amount of reagent and the reaction conditions. Ia reacts with ethyl acrylate or crotononitrile to yield the 4-alkylated derivatives VIII and IX respectively. 3-Methyl-l-phenyl-2-pyrazolin-5-one(Ib) reacts with acrylonitrile to yield only 4,4-di(β-cyanoethyl) derivative XII which on hydrolysis affords the corresponding dicarboxylic acid (XIII). 3-Amino-1-phenyl-2-pyrazolin-5-one(Ic) adds to two molecules of ethyl acrylate or acrylonitrile to yield the 4,4-disubstituted derivatives XIV and XV, but only to one molecule of benzalacetophenone to yield the 4-substituted 3-amino-2-pyrazolin-5-one derivative XVIII. The pyrazolopiperidine derivative(XVI) was obtained on treatment of Ic with ethyl crotonate in the presence of sodium ethoxide.
Synthetic Studies of Bacitracin. IX. Synthesis of Peptide Fragments for Bacitracins of Cycloheptapeptide Formula
Authors: Munekata Eisuke , Shiba Tetsuo , Kaneko Takeo 
Published: July 2006

Abstract
In the synthetic study of bacitracins, peptide fragments corresponding to a branched part of bacitracin F, i.e., (S)-2-(2-methylbutyryl)thiazole-4-carboxylic acid 1-succinimidyl ester (III) and l-leucyl-γ-t-butyl-d-glutamyl-l-isoleucine (IV), were prepared. As a macrocyclic part of bacitracin A and F of cycloheptapeptide formula, cyclo- (Nα-benzyloxycarbonyl-l-lysyl-Nδ-cyclopentyloxycarbonyl-d-ornithyl-l-isoleucyl-d-phenylalanyl-l-histidyl-β-benzyl-d-aspartyl-l-asparaginyl) (V) was synthesized through cyanomethyl ester method.
The Reaction of β-Lactones with Acid Chlorides Catalyzed by Aluminum Chloride
Authors: Nakabayashi Tadaaki , Tanaka Yumo , Ito Suketaka 
Published: July 2006

Abstract
Aluminum chloride-catalyzed reactions of β-lactones with acid chlorides were studied. 3-Propanolide and 3-methyl- and 2-methyl-3-propanolide all undergo predominantly the O-alkyl bond fission to give mixed anhydrides of β-chloropropionic acid. The reaction was postulated to proceed via dichloraluminum β-chloropropionate.
Effect of Pressure on the Rate of Solvolysis. Formolysis and Methanolysis of Secondary Alkyl Tosylates
Authors: Sera Akira , Yamagami Chisako , Maruyama Kazuhiro 
Published: July 2006

Abstract
The effect of pressure on the formolysis and methanolysis rates of representative secondary alkyl tosylates was investigated, and the activation volumes, ΔV0\eweq, were estimated. The values of activation volume for formolysis were found to correlate excellently with σ*. This conformity of ΔV0\eweq to the Hammett-type correlation is interpreted as a consequence of the kc-character of the reaction. The values of activation volume for methanolysis, however, converged to more negative values. The ks-character of methanolysis is thought to be responsible for this behavior. The kc-ks-hybrid nature of the reaction is also discussed.
Photochemical Reduction of Thiobenzophenone. Reduction by Dihydroaromatic and Related Compounds
Authors: Ohnishi Yutaka , Ohno Atsuyoshi 
Published: July 2006

Abstract
Photochemical reduction of thiobenzophenone by 1,4-dihydrobenzene, 1,4-dihydronaphthalene, 9,10-dihydroanthracene, 1,3,5-cycloheptatriene, and acridane was studied. Relative reactivities and product analyses have revealed that the reaction is initiated by hydrogen-abstraction (one-electron-transfer followed by a proton migration) with thiobenzophenone in the n,π* triplet state. Inability of diphenylmethane to undergo the reaction can be interpreted by means of this mechanism.
The Distribution of 2-Thenoyltrifluoroacetone between Several Organic Solvents and an Aqueous Solution and Its Extraction of Sodium (I) into Methyl Isobutyl Ketone
Authors: Sekine Tatsuya , Takahashi Yoshihiro , Ihara Naohiko 
Published: July 2006

Abstract
Aqueous solutions containing sodium hydroxide and sodium perchlorate at various mixing ratios, 1 m Na-(OH, ClO4), were equilibrated with several organic solvents containing 2-thenoyltrifluoroacetone (TTA) at 25°. From the measurements of the hydrogen-ion concentration of the aqueous phase, the (KD+l)Ka−1 values, where KD is the distribution constant and Ka is the acid dissociation constant of TTA, were obtained; they were, 107.17(hexane), 107.74 (CCl4), 108.01 (C6H6) and 108.17 (CHCl3). From the values of KD obtained in another study, the value of Ka was determined to be 10−6.28. However, a much lower value than that expected was obtained for the MIBK system; this was due to the extraction of sodium (I) with TTA. The extraction was also confirmed by the distribution experiments of sodium (I). The extraction constant, Kex=[NaA]org/[Na+] [A−] (where A− is the TTA anion), was found from these results to be 100.86 in 1 M NaClO4 and 100.79 at an infinite dilution.
The Isomerization of Propylene Oxide on Metal Oxides and Silica-Magnesia Catalysts
Authors: Okamoto Yasuaki , Imanaka Toshinobu , Teranishi Shiichiro 
Published: July 2006

Abstract
The isomerization of propylene oxide was carried out over silica-magnesia catalysts and metal oxides at 260–270°C using a pulse reactor. The main products of the reaction were propionaldehyde, acetone, allyl alcohol, 1-propanol, and acrolein. Propionaldehyde and acetone are produced on acidic and basic sites respectively. Allyl alcohol is formed over acid-base bifunctional catalysts. 1-Propanol and acrolein are mainly produced through hydrogen-transfer reactions between allyl alcohol and propionaldehyde and propylene oxide. As regards these reactions, acid-base bifunctional catalysts are favorable and the reaction rate depends on the electron-donating power of the hydrogen acceptor and the basic strength of the catalyst. The acid sites on silica-magnesia catalysts are attributed to the forsterite produced by the reaction of magnesium oxide and silica gel, and the basic sites, to the magnesium oxide remaining. The metal oxides, such as magnesium and calcium oxides, are considered to have very weak acid sites.
Diffusion Coefficients of Bolaform Electrolytes in Aqueous Solution
Authors: Uedaira Hisashi 
Published: July 2006

Abstract
The diffusion coefficients of sodium salts of m-benzene disulfonate, 1,5-naphthalenedisulfonate, 1,2-ethanedisulfonate, and 1,4-butanedisulfonate in aqueous solutions were measured at 25°. The concentration dependence of the diffusion coefficients for sulfonates decreased with increasing charge distance and was smaller than that of the corresponding ordinary 2 : 1 electrolytes. The concentration dependence of diffusion coefficient for sodium m-benzenedisulfonate was the largest. It is shown that bolaform electrolytes behave like normal 1 : 1 electrolytes in the concentration range where the ion atmosphere around each charged group is independent.
The Electronic Absorption Spectra and Electronic Structures of Aromatic Azides, Nitrenes, and Diazonium Ions
Authors: Kashiwagi Hiroshi , Iwata Suehiro , Yamaoka Tsuguo , Nagakura Saburo 
Published: July 2006

Abstract
Electronic spectra were measured for azidobenzene, 1-azidopyrene, benzenediazonium ion, and 1-pyrenediazonium ion at room temperature, and also for nitrenobenzene and 1-nitrenopyrene at liquid nitrogen temperature. The π-electron structures of these compounds were calculated by the Pariser-Parr-Pople LCAO SCF MO CI method for the closed-shell systems and by the restricted open-shell SCF MO CI method for the open-shell systems. The calculated transition energies and oscillator strengths could satisfactorily explain the observed spectra. It was shown that the π-electron structures of azidobenzene and nitrenobenzene are similar to those of dimethylaniline and the benzyl or anilino radical, respectively.
The Electronic States of Tetracyanoethylene and Its Anion Radical as Studied by Their Infrared Spectra
Authors: Iida Yôichi 
Published: July 2006

Abstract
The infrared spectra of tetracyanoethylene (TCNE) and its anion radical in the rock-salt region were examined in order to observe any appreciable frequency differences between their corresponding bands. The vibrational assignments were made, and the basic Urey-Bradley force field was determined for the TCNE anion radical. By comparing them with those of the neutral TCNE, we discussed the difference in the electronic states between the neutral TCNE and its anion radical. The half-occupied molecular orbital of the TCNE anion radical was found to belong to the B2g irreducible representation.
Anodic Oxidation of Benzoic Acid in Nitriles
Authors: Matsuda Yoshiharu , Kimura Kazuo , Iwakura Chiaki , Tamura Hideo 
Published: July 2006

Abstract
The anodic oxidation of benzoic acid in acetonitrile and propionitrile was studied. Electrolysis was employed under a controlled potential or current. Benzoic acid was changed into an intermediate benzoyloxy radical through de-electronation in acetonitrile, and the resulting radical was reacted with acetonitrile to give N-acetylanthranilic acid in a 38% yield under constant potential electrolysis. In propionitrile, the anodic oxidation gave N-propionylanthranilic acid, N-propionylbenzamide, and dipropionylamine. No Kolbe-type reaction was observed.
The Molecular and Crystal Structure of the p-Bromobenzoate of an Unusual Birch Reduction Product
Authors: Furusaki Akio , Hamanaka Nobuyuki , Matsumoto Takeshi 
Published: July 2006

Abstract
It has already been found that the Birch reduction of 1,1,4aα-trimethyl-2α-hydroxy-8-methoxy-1,2,3,4,4a,9-hexahydrophenanthrene affords a tetrahydro derivative, contrary to expectations. The present paper will describe the details of the molecular structure of the unexpected reduction product, as revealed by an X-ray crystal analysis of its p-bromobenzoate (racemate). The crystals are triclinic, with two molecules in a unit cell of the dimensions: a=11.155, b=18.123, c=5.912 Å, α=94°39′, β=111°35′, and y=90°42′. The space group is P\bar1. The intensity measurement was made on an automatic four-circle diffractometer with CuKα radiation. The structure was solved by the heavy-atom method, and was refined by the block-diagonal-matrix least-squares method, anisotropic thermal motions being assumed for all the non-hydrogen atoms. From a difference map, twenty-six of the thirty-one hydrogen atoms were also found. The final R factor was 6.5%. As a result of the present study, it has been found that the C ring of cyclohexene-type shows an unusual behavior. The length of the C–C single bond opposite to the double bond in this ring is found to be only about 1.34 Å. This remarkable shortening seems to be due to special vibrations of the two atoms concerned. The whole cyclohexene ring takes a considerably flattened, half-chair form.
The Coordination Bonding and Stability of the 1 : 1 Complexes of Copper(II) with Various Bidentate Ligands in Aqueous-methanolic Solutions
Authors: Yokoi Hiroshi , Otagiri Masaki , Isobe Taro 
Published: July 2006

Abstract
ESR and spectrophotometric studies have been made of a number of 1 : 1 complexes of copper (II) with ethylenediamine, its analogues, and amino acids in aqueous-methanolic solutions. It has been shown that the complexes in the solutions are characteristic of copper(II) ions with a normal tetragonal environment and that their metal-ligand bondings are intermediate in the degree of covalency between those of hydrated cupric ions and the corresponding 1 : 2 complexes. The disproportionation constants and their temperature dependences, determined for the 1 : 1 complexes by the ESR and spectrophotometric methods, have been discussed, with particular empahsis on the fact that those values are in fair agreement with those derived from the step-by-step formation constants and the thermodynamic data obtained in aqueous solutions in the literature.
ESR Studies of Dimer Formation by the β-Diketone Chelate Complexes of Copper(II) in Toluene
Authors: Yokoi Hiroshi , Isobe Taro 
Published: July 2006

Abstract
A study of the ESR spectra of several β-diketone chelate complexes of copper(II) in the frozen solution of toluene has revealed that triplet-state dimers are formed at high concentrations in the solution and that these dimers are in equilibrium with only the monomers. The approximate equilibrium constants have been determined by a careful analysis of the ESR spectra observed in various concentrations. Structures for the dimers have been suggested from magnetic parameters properly determined using a point dipole model.
Rocker-type DTA Apparatus for Fluid Samples
Authors: Tanaka Satohiro 
Published: July 2006

Abstract
A Rocker-type DTA apparatus, with agitation by rocking, has been developed for use in the thermal analysis of various fluid mixture systems. The heater block, with its assembled cells, is continuously rocked at 20 r.p.m. with a rocking of 180° angle. The glass cell has a volume of about 8 ml and is sealed by means of a burner with a sample of about 5 ml. Distilled water is used as the inert reference in the reference holder. Two thermocouples are inserted in each cell, one to determine the temperature difference and the other for sample temperature measurements. The double thermocouple gives a constant transition temperature of the sample over a wide range of heating rates. The apparatus is applied to solid-liquid and starch-water systems. Variables affecting the DTA thermogram of the K2Cr2O7–H2O system are investigated, and a method is established to correlate the DTA curve with the solubility curve for the system.
Nickel(II), Cobalt(II), Palladium(II) and Beryllium(II) Chelates of 2,4,6-Heptanetrione
Authors: Sagara Fumio , Kobayashi Hiroshi , Ueno Keihei 
Published: July 2006

Abstract
Divalent metal chelates of heptane-2,4,6-trione (H2daa) were synthesized and their structures were discussed. Nickel(II), cobalt(II) and palladium(II) ions gave Ni(Hdaa)2·2H2O, Ni2(daa)2·4H2O, Ni2(daa)2·4Py, Co(Hdaa)2·2H2O, Co2(daa)2·4H2O, Co2(daa)2·4Py, Pd(Hdaa)2 and Pd(Hdaa)2·2H2O respectively, while beryllium (II) ion unexpectedly gave bis (2-amino-2-heptene-4,6-dionato) beryllium (II) which resulted from an amino-derivative of the original ligand. Spectroscopic results suggested that the coordination structure of nickel(II) and cobalt(II) ions was octahedral hexacoordinate, that of palladium(II) ion square planar tetracoordinate and that of beryllium(II) ion tetrahedral tetracoordinate. NMR study of the palladium(II) chelate suggested partial enolization of an uncoordinated carbonyl group. It was also found that nickel, cobalt and platinum ions promoted catalytically the bimolecular-condensation of heptane-2,4,6-trione.
Calmagite: The Formation Constants of Zinc(II) Chelates and Its Use as a Metal Indicator
Authors: Nakagawa Genkichi , Wada Hiroko , Fujita Yoshio 
Published: July 2006

Abstract
The acid dissociation constants of Calmagite [1-(2-hydroxy-5-methylphenylazo)-2-naphthol-4-sulfonic acid] and the formation constants of zinc(II) chelates have been determined spectrophotometrically at 25°C and at the ionic strengths of 0.1 and 1.0. In an ammoniacal medium zinc forms mixed-ligand complexes with Calmagite (I3−) and ammonia (X); ZnIXn−. The formation constants of the zinc(II)-Calmagite chelates are logKZnI=11.75, logKZnI2=7.82, logKZnIXx=2.09, and logKZnIX2x=1.70 (μ=1.0). Calmagite is recommended as an indicator for the titration of zinc(II) with EDTA. The color transition of Calmagite is clearer and sharper, and the aqueous solution of the indicator is more stable, than in the case of Eriochrome Black T.
Selective Activation of Methylene or Methine Groups in Coordinated Dipeptide Schiff Bases
Authors: Uyama Osamu , Nakao Yasuo , Nakahara Akitsugu 
Published: July 2006

Abstract
Nickel(II) and cobalt(III) chelates of the Schiff bases derived from salicylaldehyde and dipeptides such as glycylglycine, glycylalanine and alanylglycine have newly been prepared. The reactivity of methylene or methine groups in the dipeptide moieties of those Schiff base chelates has been investigated on the basis of their PMR spectra in D2O. It has been confirmed that the methylene or methine protons of the N-terminal amino acid residue are more easily activated than those of the C-terminal amino acid residue.
On the Mechanism of the Acid Catalysis and New Activating Agents in the Fusion Reaction of an Acylated Sugar with a Purine Derivative
Authors: Sekiya Masao , Yoshino Teruo , Tanaka Hisayuki , Ishido Yoshiharu 
Published: July 2006

Abstract
An examination of the site where the acidic catalysts might strongly interact in the fusion reaction of a purine derivative with a fully-acylated sugar led to the conclusion that a purine derivative was activated by the interaction with the catalysts, and, moreover, resulted in the discovery of a new type of activating agent other than the acidic catalysts which had previously been known in the fusion method. In the presence of an excess amount of activating agents, e.g., p-nitrophenol, the condensation reaction of theophylline with 1,2,3,4,6-penta-O-acetyl-β-d-glucopyranose proceeded, even in the absence of p-toluenesulfonic acid, to give the corresponding nucleoside. Some of the activating agents were found to form molecular compounds with theophylline, and a few of the latter to afford the corresponding nucleoside similarly. A possible mechanism for the activation process of theophylline by the above agents was discussed.
The Reversible Acylation of β-Diketone with Acyl Chloride in the Presence of Aluminum Chloride
Authors: Matsui Kiyotada , Motoi Masatoshi , Nojiri Tetsuro 
Published: July 2006

Abstract
The treatment of acetylacetone (I) with n-butyryl chloride in the presence of aluminum chloride in nitrobenzene gave n-butyrylacetone and di-n-butyrylmethane at 45°C. The same products were obtained, along with n-butyric acid, when n-butyrylacetone or di-n-butyrylmethane was treated with acetyl chloride under analogous conditions. The reactions between I and benzoyl chloride and between benzoylacetone or dibenzoylmethane and acetyl chloride gave products consisting of I, benzoylacetone, dibenzoyl-, diacetylbenzoyl-, acetyldibenzoyl-, tribenzoyl-methane, and benzoic acid. These findings show that β-diketone can reversibly react with acyl chloride to form new β-diketones by way of the mixed triacylmethanes. The acylation mechanism is discussed.
The Transacylation between β-Diketone and Ester in the Presence of Aluminum Chloride
Authors: Matsui Kiyotada , Motoi Masatoshi 
Published: July 2006

Abstract
The reaction of acetylacetone with an equivalent of phenyl benzoate in the presence of 2 equivalents of aluminum chloride in nitrobenzene afforded benzoylacetone (26% yield), dibenzoylmethane (4%), and phenyl acetate (37%), together with small amounts of phenolic ketones at 45°C. The total yield, based on the acyl groups introduced into the β-diketones, is similar to the yield of the ester newly formed. Such a similarity, suggestive of a transacylation, was also observed both on the use of p-nitrophenyl benzoate and on the treatment of benzoylacetone with phenyl benzoate or on that of dibenzoylmethane with p-nitrophenyl acetate. The non-formation of triacylmethanes is a strong evidence for the transacylation reaction, in which β-diketones and some esters exchange acyl groups directly. The analogous treatment of acetylacetone with α-naphthyl benzoate produced phenolic ketones, such as 2-acetyl- and 4-acetyl-1-naphthol, and the same benzoylated ketones as above in yields of 30 and 32% respectively. The considerably higher ratio of the 2-acetyl to the 4-acetyl isomer than that from the Fries rearrangement of α-naphthyl acetate indicates that another transacylation is accompanied by a rearrangement proceeding through complexes different from those in the Fries rearrangement.
The Crystal Structures of Methylene Dibromide and Methylene Diiodide
Authors: Kawaguchi Takemi , Wakabayashi Akira , Matsumoto Mitsuhiro , Takeuchi Toru , Watanabe Tokunosuke 
Published: July 2006

Abstract
The crystal structures of methylene dibromide and methylene diiodide (Form II) have been determined by the X-ray diffraction method at about −90°C and about −20°C respectively. Both the crystals are isomorphous, with monoclinic space group C2h6–C2/c. Unit cells containing eight molecules have these dimensions: a=12.239(12), b=4.459(15), c=15.212(16) Å, and β=113.54(7)° for methylene dibromide, and a=13.346(3), b=4.720(90), c=16.479(5) Å, and β=114.48(8)° for methylene diiodide. The orientations of the methylene groups have been obtained by lattice-energy calculations.
Syntheses of New Arginine Derivatives as a Substrate for Trypsin or Papain
Authors: Nishi Norio , Noguchi Junzo 
Published: July 2006

Abstract
Two new enzymic substrates, tosyl-l(d or Dl)-arginine-p-nitroanilide (l-TAPA, d-TAPA, and Dl-TAPA) and acetyl-l(d or Dl)-arginine-p-nitroanilide (l-AAPA, d-AAPA, and Dl-AAPA) were synthesized by the route for benzoyl-l-arginine-p-nitroanilide (l-BAPA) reported previously. The previous method for synthesis of l-BAPA was then improved by the direct benzoylation of l-arginine-p-nitroanilide dihydrochloride (l-APA), into which Nα-benzyloxycarbonyl-Nω-nitro-l-arginine-p-nitroanilide was converted by the simultaneous removal of benzyloxycarbonyl and nitro groups with hydrogen fluoride. This route has the advantages of shorter reaction steps and a better over-all yield than in the case of the previous method. The method is also applicable to the synthesis of l(d or Dl)-AAPA, but it is hard to prepare l(d or Dl)-TAPA by the method.