bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Acylation of 2,3-Dimethyl-bz-hydroxybenzofurans and the Syntheses of Di- and Tri-methylfuroisoflavones
Authors: Kawase Yoshiyuki , Nanbu Mutsumu , Miyoshi Fumihisa 
Published: July 2006

Abstract
The acylation of 2,3-dimethyl-4-hydroxybenzofuran (1) with acetic acid, phenylacetic acid, 2-methoxyphenylacetic acid or 2,4,5-trimethoxyphenylacetic acid, and polyphosphoric acid gave a mixture of the 5- and 7-acyl compounds (2a, b, c, d, and 3a, c, d respectively). Analogously, the isomeric 2,3-dimethyl-6-hydroxybenzofuran (6) gave the 5-acyl compounds (7a, b, c, d), two (7a, b) of which were also obtained by the Friedel-Crafts acylation of the methyl ether of 6 (9), followed by demethylation. On the other hand, the formation of a dimethylfuran ring on 2,4-dihydroxyphenyl ketones by the action of polyphosphoric acid on their 4-(α-acetylethoxy) derivatives (11a, b, c) also afforded mixtures of the ketones (7a, b, c) and isomeric ketones (2a, b, c). The benzofuranyl ketones (2 and 7) thus obtained were converted to the corresponding 4″,5″-dimethyl-furo[2″,3″:7,8]isoflavones (12b, c, d) and isomeric -furo[3″,2″:6,7]isoflavones (14b, c), and also their 2-methyl derivatives (13b, c, d and isomeric 15b, c), by the general method utilizing ethyl orthoformate, piperidine and pyridine, or acetic anhydride and sodium acetate. The furoisoflavones (12b, c and 13b, c) were also prepared by building up the dimethylfuran ring on 7-hydroxyisoflavones by the action of polyphosphoric acid or sulfuric acid on their 7-(α-acetylethoxy) derivatives (16b, c and 17b, c respectively). The alkaline degradation of these furoisoflavones (12 and 13) also gave the benzofuranyl ketones (2).
Spectroscopic Studies of Catalysis by Vanadium Pentoxide
Authors: Tarama Kimio , Yoshida Satohiro , Ishida Shingo , Kakioka Hideo 
Published: July 2006

Abstract
The role of the V=O bond in V2O5 in the adsorption of several gases was studied by measuring the electron spin resonance (ESR) and the infrared (IR) spectra. The ESR spectra of V2O5 supported on γ-Al2O3 were similar to those of VOSO4 on γ-Al2O3. When such electron-donating gases as CO, SO2 and C2H4 were adsorbed on this V2O5-γ-Al2O3, the signal intensity of ESR increased and the splitting of the h.f.s. became clear. Upon treatment with an electron-accepting gas such as O2, a reverse change was observed. In the case of V2O5 supported on SiO2, similar ESR spectra were observed by the adsorption of CO after a mild reduction. The IR spectra of V2O5 have a sharp absorption peak at 1023 cm−1 due to the stretching vibration of the (V=O)3+ bond; this peak became broader by adsorption of such gases as CO and SO2. Simultaneously, the center of the peak shifted to the red region and a weak hump appeared at 980–990 cm−1, probably due to (V=O)2+. These results of the ESR and IR measurements reveal that these electron-donating gases are adsorbed on the (V=O)3+ bonds on the surface of V2O5, and that the increase in electron densities in the adsorption sites results from adsorption of these gases. Furthermore, the role of this (V=O)3+ bond in oxidation reaction was also discussed.
Macro Rings. II. Synthesis of [2.1.1.1.1]Paracyclophane
Authors: Inazu Takahiko , Yoshino Tamotsu 
Published: July 2006

Abstract
A macrocyclic compound which incorporates five benzene rings and intervening methylene bridges as parts of a large ring structure, [2.1.1.1.1]paracyclophane I (n=2), was synthesized and then compared with a corresponding open-chain analog, X.
The Behavior of Radical Anion of Acridine as Revealed from ESR Studies
Authors: Niizuma Shigeya , Okuda Michio , Koizumi Masao 
Published: July 2006

Abstract
Nature of acridine anions produced by the addition of alkali metals to the tetrahydrofuran solutions of acridine has been studied by means of ESR and VU spectra. In excess of acridine (A), a green species G is produced. This has been identified as A−Na+ (or A−K+ etc.). A−Na+ gives under suitable conditions, ESR spectra with hfs consisting more than fifty lines. This species reverts to acridine upon addition of a small quantity of water or ethanol. With the fall of temperature, the intensity of ESR spectra of G decreases remarkably and accompanied with it, UV spectra of G also decline with no change of the spectral shape, logIvs. 1/T plots where I is either the intensity of UV absorption or of the ESR signal are satisfactorily linear; this has been interpreted to be due to a large equilibrium constant of the process, 2A− Na+\ightleftarrows(Na+A−)2 in which (Na+A−)2 is a colorless diamagnetic substance. This interpretation has led to the value of enthalpy of dissociation of (Na+A−)2 as ca. 14 kcal. When sodium is in excess, a diamagnetic violet species is produced. This has been assigned as Na+A2−Na+. The chemical processes pertaining to A−Na+ and Na+A2−Na+ can be summarized as follows:
(Remark: Graphics omitted.)
Structure and Reactivity of α,β-Unsaturated Ethers. IV. The Effects of Ring Substituents on the Acid-Catalyzed Hydrolysis Rate of Phenyl Vinyl Ether
Authors: Fueno Takayuki , Matsumura Itaru , Okuyama Tadashi , Furukawa Junji 
Published: July 2006

Abstract
The rates of hydrolysis of various ring-substituted phenyl vinyl ethers, CH2=CHOC6H4X, have been measured in 80 : 20 dioxane-water containing hydrochloric acid as catalyst. The ring substituents investigated include H, p-CH3O, m-CH3O, p-CH3, m-CH3, p-Cl and m-Cl. The reaction was first order with respect to both the acid and the ethers. It has been found that the effect of substituents on the hydrolysis rates obeys the Hammett ρσ relationship with the reaction constant ρ=−2.21 at 35°C. These results are compatible with the previous conclusion that the acid-catalyzed hydrolysis of alkenyl ethers involves the rate-determining protonation of the ethers at their β-carbon atom, to form intermediate oxycarbonium ions. It has been shown that the observed substituent effect can be rationalized from the π-electronic energy changes of the ethers on protonation, which have been calculated by an empirical molecular orbital method.
Metal Complexes with Amino Acid Amides. I. Preparations and Electronic Spectra of the Nickel(II) and Palladium(II) Complexes
Authors: Komorita Takashi , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Several planar bis(amino-acid-amidato) complexes of nickel(II) and palladium(II) have been newly synthesized and characterized mainly spectroscopically. The geometrical structures of these [M(N)4]-type complexes have been determined: palladium(II) produced both cis and trans complexes with l-alanine- and l-leucine-amidate ligands, while nickel(II) did only trans forms with glycine-, l-alanine- and l-leucine-amidates. Nickel(II) also produced cationic complexes, Ni(l-alanine-amide)2SO4 and its glycine amide analogue. The circular dichroism spectra and rotatory dispersion of the complexes containing optically active amino acid amide have been measured and discussed as for the assignments of the ligand field absorption bands of the diamagnetic planar complexes. A good correspondence was observed between the circular dichroism spectra of the nickel(II) and the palladium(II) complexes.
Solvent Effects on ρ Values of the Hammett Equation
Authors: Kondo Yasuhiko , Matsui Takeki , Tokura Niichiro 
Published: July 2006

Abstract
The effects of selvents on ρ values have been systematically treated as a two-variable problem within a linear free-energy relationship framework. It is assumed that the standard activation free energy is a continuous function of σ, a substituent variable, and ξ, a solvent variable. The applicability of the resultant equations is proved by a test of the dissociation constants (obtained from the literature) of benzoic acids in various solvents. As a result, it is proposed that these effects on ρ values can be explained in terms of the interaction or cross-term of σ and ξ. The application to the reaction rates of a typical Menschutkin reaction, obtained by experiments in ten nonaqueous solvents, suggests that the solvent dependence in these reactivities is much more complicated.
A Study of the Solvent Effect on the Polymerization of N-Phenylethyleneimine
Authors: Kagiya Tsutomu , Kondo Tomizo , Nakao Kozo , Fukui Kenichi 
Published: July 2006

Abstract
The effect of solvents on the cationic polymerization of N-phenylethyleneimine with formic acid catalyst has been studied quantitatively. The polymerization rates in the various solvents used increase in the following order: diethyl ether\simeqtetrahydrofuran&lt;toluene\simeqcarbon tetrachloride&lt;anisole&lt;methyl acetate&lt;ethylene dichloride&lt;N,N-dimethylacetamide&lt;dimethyl sulfoxide&lt;epichlorohydrin&lt;acetonitrile. In polar solvents with high dielectric constants, the rates are much larger than those in nonpolar solvents with low dielectric constants. However, in the solvents with similar dielectric constants, such as acetonitrile and N,N-dimethylacetarnide, ethylene dichloride, methyl acetate and tetrahydrofuran, and anisole and diethyl ether, the rates decreased with an increase in the nucleophilicity of the solvents, and the dependence of the polymerization rate on the nucleophilicity of the solvents is much larger in polar solvents than in nonpolar solvents. The propagation rate was markedly influenced by the nature of the solvent, whereas the initiation rate was only a little influenced.
Syntheses and Reactions of Functional Polymers. XLV. Synthesis and Properties of Poly(N-glycidyl-2-oxazolidone)
Authors: Endo Takeshi , Numazawa Ryozo , Okawara Makoto 
Published: July 2006

Abstract
N-Glycidyl-2-oxazolidone was synthesized by the reaction of N-sodium-2-oxazolidone with epichlorohydrin. N-Glycidyl-2-oxazolidone was polymerized with such Lewis acids as boron trifluoride etherate and aluminum chloride to give a white powder. These polymers adsorbed phenol and methyl bromide effectively. In addition, the copolymerization of N-glycidyl-2-oxazolidone with styrene was carried out, and the amount of the adsorption of methyl bromide on the copolymers was measured. The amount of the adsorption of methyl bromide increased in the copolymers as the content of 2-oxazolidone moiety increased. A 1 : 1 molar complex of stannic chloride with N-glycidyl-2-oxazolidone was isolated; when the complex was heated, poly(N-glycidyl-2-oxazolidone) was obtained quantitatively.
Studies of the Derivatives of Epichlorohydrin. III. A New Method of Preparing γ-Alkoxy-γ-butyrolactones
Authors: Kuwamura Tsunehiko , Takahashi Hideo 
Published: July 2006

Abstract
When alkyl glycidyl ethers derived from epichlorohydrin and alcohols were treated with sodium cyanide, the corresponding γ-alkoxy-β-hydroxybutyronitriles (I) were obtained. The hydrolysis of I with aqueous alkali metal hydroxide, followed by acidification and distillation, gave γ-alkoxy-γ-butyrolactones (II). The structure of II was confirmed by chemical and physical means. The reaction paths of I to II were also studied.
Effects of Substituents on the Chain-transfer Reactivities of Nuclear-substituted Benzaldehydes to Polymer Radicals
Authors: Yamamoto Tadahiro , Hasegawa Masaru , Otsu Takayuki 
Published: July 2006

Abstract
In order to study the effect of substituents on the chain-transfer reactivities of nuclear-substituted benzaldehydes toward polymethyl methacrylate (poly-MMA) and polystyryl (poly-St) radicals, the chain transfer constants (C) of six kinds of benzaldehydes in radical polymerizations of these monomers were determined at 60°C. The C values of all the substituted benzaldehydes toward the poly-MMA radical were larger than that of unsubstituted benzaldehyde, regardless of the electron-repelling or electron-attracting nature of the substituents, while those toward the poly-St radical increased with an increase in the electron-attracting nature of the substituents. The relative reactivities toward the poly-MMA radical could not be correlated with the ordinary Hammett equation, but they could be with this modified equation: log(k⁄k0)=ρσ+γER, with ρ=+0.2 and γ=0.7. On the other hand, the relative reactivities toward the poly-St radical also fit a modified Hammett equation with ρ=+1.4 and γ=0.65.
Studies on Telomerization of Vinyl Chloride with Carbon Tetrabromide
Authors: Asahara Teruzo , Chou M C 
Published: July 2006

Abstract
The radical telomerization of vinyl chloride with carbon tetrabromide was investigated. The telomers with n=1 and 2 in Br(CHClCH2)nCBr3 were isolated and identified. The molecular weight distribution of the telomers was determined by thin-layer chromatography (TLC), and it was found that the distribution varied a little with the variation of reaction conditions. From the results of the TLC, the chain transfer constants (Cn) of polylvinyl chloride radical to carbon tetrabromide were calculated, and a monotonous increase in Cn with the increasing n was found. The effects of initial ratio of vinyl chloride to carbon tetrabromide, reaction time and temperature on the conversion of vinyl chloride and the average molecular weight of the telomer were investigated. Bromoform was also used as a telogen instead of carbon tetrabromide, and the results were compared in both systems.
Molecular Orbital Treatment of Nitric Oxide Radicals. III. Spin Distributions and g Factors of Aromatic Nitric Oxide Radicals
Authors: Kikuchi Osamu 
Published: July 2006

Abstract
The spin distributions and g factors have been calculated for seveial aromatic nitric oxide radicals. The spin distributions calculated by the open-shell SGF method with configuration interaction, and by the unrestricted SCF method with the annihilation of the quartet component from the single determination wave function, agreed with the experimental values estimated from the ESR spectra. The contributions of the lone-pair orbital of the oxygen and of the N–O σ-bonding orbital to the g factor were calculated, the calculated g factors in solution being in the range of 2.005–2.006; these values were then discussed on the basis of the electronic structures of nitric oxide radicals.
The Reactions of a Mixture of Benzene and cis-2-Butene Photosensitized by Cadmium
Authors: Tsunashima Shigeru , Satoh Shin , Sato Shin 
Published: July 2006

Abstract
Using the cadmium-photosensitized cis-trans isomerization of cis-2-butene, the lifetime of triplet benzene has been estimated to be of the order of 10−5 sec for both benzene-d0 and -d6. This technique provides a new method for measuring the lifetime of the triplet state of some molecules.
Electrodeposition of Water-soluble Resin by a Constant Voltage or by Pulses
Authors: Nakamura Yoshio , Oki Fumio , Nozaki Hiroshi 
Published: July 2006

Abstract
The mechanism of deposition was investigated using maleic-linseed oil as a sample. The deposition was made by a constant voltage or by continuous pulses with high voltages, and the initial current-time relations were observed by means of a synchroscope. When we applied pulses with α⁄β values which were smaller than a value, the current decreased gradually after some time and a deposited film was found on the anode, but the decreases in the current was not found for a long time when the value of β was much larger than the value of α. The induction time was found from the current-time curve observed during a constant voltage deposition. These results were discussed from the standpoint that the deposited film is formed by coagulation resulted from ionic combination with hydrogen ions.
Reactions of Nickel(II), Copper(II) and Palladium(II) Complexes of Bis(acetylacetone)ethylenediimine with Nitric Oxide
Authors: Masuda Isao , Tamaki Motonori , Shinra Koichiro 
Published: July 2006

Abstract
Through reaction with nitric oxide, divalent Ni, Cu, and Pd complexes of bis(acetylacetone)-ethylenediimine have been shown to yield fine crystalline compounds of the general formula M(C12H17N3O3), where M=Ni or Cu, and of M(C12H16N4O4) where M=Ni, Cu or Pd, depending on experimental conditions. They are insoluble in water. The former compounds are rather soluble in common organic solvents, but the latter are sparingly soluble, except in pyridine. On the basis of analytical data and IR-spectral analyses, they are thought not to be nitrosyl metalcomplexes but oxime type complexes.
Ionic Equilibria in Mixed Solvents. IV. Solvent Effect on Dissociation Constants of Acids
Authors: Ohtaki Hitoshi 
Published: July 2006

Abstract
Equilibrium of hydronium ions with alkoxonium ions in water-alcohol mixtures being taken into account, solvent effects on dissociation constants of acids were quantitatively interpreted by the following: free energy changes on transferring ions from an aqueous solution to a mixed solvent and difference in standard states in different solvent compositions. Choosing suitable values for effective ionic radii for ions involved, satisfactory agreements were found between experimental and calculated values of ΔpK, the difference of pK in water and in an aqueous mixture, for positively charged acids (e.g., ammonium, anilinium, etc.) as well as neutral acids yielding a negatively charged conjugate base (e. g., acetic acid, benzoic acid, p-nitrophenol, etc.).
Spectroscopic Studies of the Structures of the Dimer of Diethylaluminum 2-Aminoethoxide (AlEt2OCH2CH2NH2)2 and Related Compounds
Authors: Sato Hideo , Tarao Ryokichi , Higashi Hiromi 
Published: July 2006

Abstract
The infrared and proton nuclear magnetic resonance spectra of the solutions of diethylaluminum 2-aminoethoxide (AlEt2OCH2CH2NH2)2 and related compounds were measured. The infrared frequencies and intensities of the NH2 stretching, scissors, and rocking vibration bands, and the NMR internal chemical shifts of the ethyl groups attached to the aluminum atom were compared with the corresponding data of suitable model compounds. It was concluded by taking the results of these experiments into consideration that (AlEt2OCH2CH2NH2)2 was represented by the structural formula I with two Al←NH2 coordination bonds. Similarly, most of the related compounds studied were reasonably represented by the formulas with two Al←NRR′ coordination bonds, while (AlEt2OCH2CH2N(C6H11)2)2 was assumed to be represented by formula III with two Al←O coordination bonds, exceptionally.
Synthesis of Adamantane Derivatives. III. Synthesis of Adamantane Heterocycles
Authors: Sasaki Tadashi , Eguchi Shoji , Toru Takeshi 
Published: July 2006

Abstract
Preparation of 1-adamantyl and adamantane-1-carbonyl derivatives having benzimidazole, 1,3,5-oxadiazole, oxazoline-2, quinoxaline, 2-aminothiazole, thiazolone, 2-methylthiazole, 1,2,3-thiadiazole, pyrazole or pyrazoline ring is described.
Reactions of α-Cyano-β-methoxy-β-alkylacrylic Esters with Hydrazine and Hydroxylamine
Authors: Baba Hideo , Hori Isaburo , Hayashi Toshio , Midorikawa Hiroshi 
Published: July 2006

Abstract
α-Cyano-β-methoxy-β-alkyl (Me, Et, n-Pr, n-Bu, n-Am, and i-Bu)-acrylic esters (I) react with hydrazine to give β-hydrazino intermediates. The hydrazino group of these intermediates is cyclized preferentially between its terminal NH2 and the cyano group in a neutral or acidic medium to give 5-aminopyrazole derivatives, and preferentially between the terminal NH2 and the ester group in the presence of a base to give 5-pyrazolone derivatives. When the β-alkyl of I is isopropyl, t-butyl], etc., I affords only the 5-pyrazolone derivatives in the reaction with hydrazine. The reactions of I with hydroxylamine gave 5-aminoisoxazole derivatives, but in the case of the β-t-butyl derivative of I they gave 5-aminoisoxazole accompanied by the 5-isoxazolone derivative.
Syntheses of Pterocarpans. III. Synthetic Analogues of Neodulin
Authors: Fukui Kenji , Nakayama Mitsuru , Harano Teruo 
Published: July 2006

Abstract
4′,5′-Dimethoxy-2′-hydroxyfurano[3″,2″:6,7]isoflavone was obtained from isoelliptol isoflavone by selective demethylation with boron tribromide. The treatment of the 2′-hydroxyisoflavone with sodium borohydride in absolute alcohol - tetrahydrofuran afforded 8,9-dimethoxyfurano[3′,2′:2,3]pterocarpan. 8,9-Dimethoxyfurano[2′,3′:3,4]pterocarpan was prepared from elliptol isoflavone by a similar procedure.
Photoreversible Photographic Systems. V. Reverse Photochromism of (Photospiran/Acid) System in Acetone
Authors: Shimizu Isamu , Kokado Hiroshi , Inoue Eiichi 
Published: July 2006

Abstract
1,3,3-Trimethylindolino-6′-nitro-benzopyrylspiran (1) exhibits a photoreversible color change which is called “photochromism”. However, it is transformed from a colorless form (A) into a colored form (C) which has a salt-like structure when acid such as malonic acid is added into acetone without irradiation with light. The color is bleached by irradiation with light. The color reappears thermally as the light source is removed. This photoreversible color change is termed “reverse photochromism”. Another colored form (B) of compound (1) which has a merocyanine dye-like structure is converted into (C) as acid is added into the solution (B). The quantum yield of the photoconversion from C to A by irradiation with visible light depends on the solvent polarity. The quantum yield of the photoconversion from A to B also depends on the solvent polarity.
Freezing of the Droplets of Aqueous Solution Aerosols
Authors: Uzu Yuhei , Sano Isamu 
Published: July 2006

Abstract
By atomizing aqueous solutions both of electrolytes and non-electrolytes, fog droplets of 8μ in diameter were prepared, and their freezing temperatures were measured in a thermostat-like cold chamber fitted with an electrically heated platinum wire. The results were compared with that obtained with fog droplets of pure water of the same size. It was found that non-electrolytes hardly influence the freezing, whereas electrolytes do a great deal. The freezing temperature rises in the presence of an electrolyte and varies with its concentration, the highest temperatures being observed at the concentrations around 1×10−4m for 1-1 type electrolytes and at lower concentrations for 1-2 and 1-3 type electrolytes. K+ is the most effective of the alkali metal cations having the same species of anion in common, and I− of the halide anions having the same species of cation in common. Applying the theory of nucleation, the sizes of the hydrated K+ and the critical nucleus developed from it for ice-nucleation were estimated to be about 6 and 21 Å in radius, respectively.
The Crystal Structure of 5,5-Dimethyl-2-oxo-2-hydroxy-1,3,2-dioxaphosphorinane Monohydrate
Authors: Murayama Wataru , Kainosho Masatsune 
Published: July 2006

Abstract
The crystal structure of 5,5-dimethyl-2-oxo-2-hydroxy-l,3,2-dioxaphosphorinane monohydrate (I) has been determined by the three dimensional X-ray diffraction method. The crystals belong to monoclinic system, with space group P21. The unit cell dimensions are; a=9.50, b=5.86, c=8.31 Å, β=106°8′, and two molecules per unit cell. The six-membered dioxaphosphorinane ring has a chair conformation, with P=O bond in equatorial position. The bond angles and distances of the phosphate group are similar to those found in the corresponding acyclic phosphates.
A Theory of the Gel-forming Polymerization of Polyvinyl Compounds
Authors: Fukui Kenichi , Yamabe Tokio 
Published: July 2006

Abstract
A theory of the molecular-size distribution of the cross-linked polymers to be formed from a mixture of vinyl monomers with a distribution of functionalities by radical polymerization is presented. It is assumed that all the unconverted vinyl groups are equireactive to the propagation, which proceeds without cyclization. The distribution is obtained by applying the statistical theory of gel formation with multifunctional interunit junctions, which are, in this case, equivalent to cross-linking chains. The general theory is applied to three practical cases; the curing reaction of unsaturated polyesters, the polymerization of polyvinyl compounds, and the copolymerization of vinyl and divinyl compounds.