bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iodination Reactions of Ketones in the Reversed Micellar Systems of Dodecylammonium Propionate in Hexane
Authors: Sen\={o} Manabu , Araki Koji , Shiraishi Shinsaku 
Published: July 2006

Abstract
The iodination reactions of ketones in the reversed micellar systems of dodecylammonium propionate (DAP) in hexane were studied at 25.0 °C in relation to the enzymatic function of aldolase or enolase. The reaction rate in the DAP reversed micellar system is 106–107 times greater than that in the system without DAP, 100 times greater even in comparison with that in DAP aqueous system at pH 6.8. As in the ammonium ion catalyzed reaction in aqueous media, the reaction in the presence of DAP proceeds via ketimine formation between ammonium groups of DAP and acetone and subsequent enolization of ketimine to enamine, which reacts very rapidly with iodine. The catalytic effect of DAP reversed micellar system in each reaction step was discussed. Further, this reversed micellar system shows a marked selectivity for acetone as compared with higher analogs.
α,β-Unsaturated Carboxylic Acid Derivatives. XI. Convenient Synthesis of tert-Butyl 2-Alkoxy- and Hydroxy-2-acetylamino-3-mono- or 3,3-dihaloalkanoates
Authors: Shin Chung-gi , Sato Yoshiaki , Yoshimura Juji 
Published: July 2006

Abstract
It was found that the halogenation of t-butyl 2-acetylamino-3-bromo-2-alkenoate (3) by NBS or NCS gave t-butyl 2-acetylimino-3,3-dihaloalkanoate (6 and 7). The addition of water or several saturated, unsaturated and polyhydric alcohols to the carbon-nitrogen double bond of 6 or 7 was accomplished to give t-butyl 2-acetylamino-2-alkoxy- and hydroxy-3,3-dihaloalkanoate. Similarly, the treatment of t-butyl 2-bromoacetylamino-2-alkenoate in alcohol gave t-butyl 2-acetylamino-2-alkoxy-3-bromoalkanoate, via the addition of alcohol to the imino intermediate (2). The formation mechanism and the structural assignment are discussed.
The Reactions of Polychloroethanes with Phenolate and Benzenethiolate Ions in Dipolar Aprotic Solvents
Authors: Tanimoto Shigeo , Taniyasu Ryôzô , Takahashi Tôru , Miyake Takatoshi , Okano Masaya 
Published: July 2006

Abstract
The reactions of several gem- and vic-polychloroethanes containing 3–5 Cl atoms with PhONa in dimethyl sulfoxide and with PhSNa in N,N-dimethylformamide were examined. Either the mono-, di-, or tetra-substituted compounds of polychloroethylenes were obtained as the main products, depending on the kinds of substrates as well as on the amounts of the bases. The reaction products from polychloroethylenes with 2–4 Cl atoms were also examined under similar conditions for the sake of comparison. Reasonable reaction paths leading to these products were given.
Acid-catalyzed Rearrangements of Tetrahydroasatone and Tetrahydroisoasatone
Authors: Yamamura Shosuke , Terada Yukimasa 
Published: July 2006

Abstract
Tetrahydroasatone (3) and tetrahydroisoasatone (4) both are pretty unstable to various kinds of acid. Action of 6M·HCl–AcOH on the former converted it to the naphthalene-type compound (5) in high yield, whose structure was determined on the basis of its spectral data. In the case of tetrahydroisoasatone, twofold Wagner-Meerwein rearrangements take place, leading to the formation of the isomer-A (9), further rearrangements of which give rise to the bisnordiadamantane-type isomer-B (10a).
The Structures of Two Novel Neolignans, Asatone and Isoasatone
Authors: Yamamura Shosuke , Terada Yukimasa , Chen Yuh-Pan , Hong Mina , Hsu Hong-Yen , Sasaki Kyoyu , Hirata Yoshimasa 
Published: July 2006

Abstract
Isolation and structures of two novel neolignans, asatone (1) and isoasatone (2), are described. The structure of the latter, established by means of an X-ray crystallographic analysis of its dihydroxy derivative, is in full agreement with its chemical and spectral data. From a biogenetic point of view, furthermore, thermal and photochemical reactions of these neolignans and their derivatives were carried out. In particular,asatone was photochemically converted into isoasatone.
Equilibrium and 31P Chemical Shifts of the Adducts of Trialkylphosphines and Isothiocyanates, and Reactions of Triethylphosphine and Benzoyl Isothiocyanate
Authors: Akiba Kin-ya , Yoneyama Toshio , Hamada Hideaki , Inamoto Naoki 
Published: July 2006

Abstract
The adducts (3) of triethylphosphine (1) and several isothiocyanates (2) were prepared. Equilibrium constants of the adducts (5) from tributylphosphine (4) and phenyl (2b), benzoyl (2e), and p-toluenesulfonyl isothiocyanates (2f) were determined in some solvents. The 31P chemical shifts of 5 were measured in DMF, and correlated with Hammett σp constants. Reactions of 3e with 1 and 2e gave phosphonium thiocyanates of 6 and 7, and of 11, respectively. Methylation of 3e gave S-methyl N-benzoylmonothiocarbamate (16).
Studies of Heterocyclic Compounds. VIII. Synthesis and Tautomerism of 2-Hydroxypyrazolo[1,5-a]pyridine
Authors: Ochi Hisao , Miyasaka Tadashi , Kanada Kiyoshi , Arakawa Kiichi 
Published: July 2006

Abstract
2-Hydroxypyrazolo[1,5-a]pyridine (I) was synthesized by reaction of ethyl 2-pyridylacetate (IV) with hydroxylamine-O-sulfonic acid. I was shown to undergo nitrosation, nitration and bromination at C-3 position. Methylation of I with diazomethane gave 2-methoxypyrazolo[1,5-a]pyridine (V), while methylation of I with dimethyl sulfate gave a mixture of V and 1-methyl-1,2-dihydropyrazolo[1,5-a]pyridin-2-one (VI). The enol form was found to be predominant tautomeric species of I in solution. Treatment of I with acetic anhydride afforded 2-acetoxypyrazolo[1,5-a]pyridine (XIII) exclusively. 1-Acetyl-1,2-dihydropyrazolo[1,5-a]pyridin-2-one (XIV) dose not seem to intervene in the formation of thermally stable O-acetylated product (XIII).
A Novel Synthesis of 2-Trialkylphosphonio-1,3-dithiole-4-carboxylates
Authors: Pittman Charles U , Narita Mitsuaki 
Published: July 2006

Abstract
Acetylene carboxylic acids reacted with trialkylphosphine-carbon disulfide ylides to produce fair to good yields of 2-trialkylphosphonio-1,3-dithiole-4-carboxylates (4) at temperatures as low as −20 to −30 °C. The formation of these zwitterionic products, by a prototropic shift in the ylide 3, differs fron the known reaction of acetylenes, such as ethyl propiolate, with carbon disulfide and tributylphosphine to give tetrathiafuvalene derivatives. The structure of these zwitterionic products was confirmed by alkaline hydrolysis, reaction with benzaldehyde, and their IR and NMR spectra. Alkaline hydrolysis of 4 gave the corresponding carboxyl-substituted 1,3-dithioles 7. Treatment of 2-tributylphosphonio-1,3-dithiole-4-carboxylate (4e) with benzaldehyde in the presence of triethylamine resulted in the formation of 2-benzylidene-1,3-dithiole-4-carboxylic acid 8. The methine proton of the 1,3-dithiole ring of 4 in DMSO-d6, appeared at δ 5.41–6.24 as a singlet peak. These methine protons were readily exchanged by deuterium in the presence of methanol-d4, and disappeared from NMR spectra.
The Franck-Condon Factor of the \ ildeA–\ ildeX System of Ammonia
Authors: Kanesaka Isao , Usui Mami , Kawai Kiyoyasu 
Published: July 2006

Abstract
The relative intensity of the \ ildeA–\ ildeX system of ammonia was calculated by using the harmonic and devised harmonic wave functions. The calculated relative intensities do not agree completely with the observed ones. The relative intensity of the vibronic transition was also calculated. However further improvement was not obtained.
Applicability of a Viscosity Formula of Liquid Mixtures to Gaseous Mixtures
Authors: Ishikawa Tetsuya 
Published: July 2006

Abstract
Since 1929, the writer has carried out an elaborate calculation on the viscosity of binary liquid mixtures, using for an ideal mixture the formula
η=\fracη_11+\cfrack_2a_2k_1a_1\cfracz_m1-z_m+\fracη_21+\cfrack_1a_1k_2a_2\cfrac1-z_mz_m
or that in hyperbolic form
\frac(η-η_1)(1-z_m)(η_2-η_1)·z_m=\frack_2a_2k_1a_1=K(a constant)
where a is the degree of association, k the molecular field constant and zm the formal mol fraction of component 2. However, if there occurs a maximum in (η–zm) diagram, we can not evaluate K from the formula, since negative values result in the neighborhood of the maximum. In this case the formula K=η1M2a2⁄η2M1a1 may be preferable provided that the equality K=k2⁄k1=η1M2⁄η2M1 holds for gaseous mixtures where a1=a2=1. The applicability of the formulas is discussed.
Esterification of Alcohols with 1-Acylimidazole Assisted by N-Bromosuccinimide
Authors: Katsuki Tsutomu 
Published: July 2006

Abstract
Treatment of 1-acylimidazoles with alcohols in the presence of N-bromosuccinimide led to the rapid formation of the corresponding esters. The carboxylic acids with less than two hydrogen atoms at their α-positions generally gave good results. Even such a hindered ester as t-butyl pivalate could be prepared by this procedure.
The Nucleophilic Substitution of Dicarboxylic Imides on the Chelate Ring of Tris(3-bromo-2,4-pentanedionato)iron(III)
Authors: Yamamoto Yasuo , Kasuga Kuninobu , Sumita Akira 
Published: July 2006

Abstract
Succinimide and phthalimide were found to be capable of acting as a nucleophilic substituent on the chelate ring of tris(3-bromo-2,4-pentanedionato)iron(III) complex. No analogous reaction has been found between this complex and the other dicarboxylic imides, nor between other metal complexes and dicarboxylic imides including these two imides.
Reaction of Triethylphosphine with Dimethyl Acetylenedicarboxylate in the Presence of p-Chlorobenzaldehyde
Authors: Akiba Kin-ya , Yoneyama Toshio , Inamoto Naoki 
Published: July 2006

Abstract
Reaction of triethylphosphine (1) with dimethyl acetylenedicarboxylate (2) in the presence of p-chlorobenzaldehyde gave dimethyl α-(p-chlorobenzoyl)fumarate (5) and a bicyclic lactone (6). In the presence of water, reaction of 1 with 2 afforded dimethyl fumarate and triethylphosphine oxide.
Effect of Water on the Conductance of Hydrogen Halides in Diethylene Glycol
Authors: Srinivas Rao V , Kalidas C 
Published: July 2006

Abstract
The effect of addition of small amounts of water on the conductance of hydrogen chloride and hydrogen bromide in diethylene glycol at 25 °C was investigated. The Λ0 of both acids sharply decreases with the addition of water, passes through a minimum at about 1.23 wt% of water and then increases. This was explained on the basis of the changes in the proton jump mechanism due to shift of the proton transfer equilibrium, ROH2++H2O\ightleftarrowsROH+H3O+. The role of water in this equilibrium was shown to be similar to the protonation of a Hammett indicator base in acid solutions.
Ion Cyclotron Resonance Study of Ion-molecule Reactions in Benzene: Mechanism of C3H3+ Formation
Authors: Aoyagi Katsuyuki , Hasuda Yoshinori , Irie Masahiro , Hayashi Koichiro , Sohma Junkichi 
Published: July 2006

Abstract
Ion-molecule reactions in gaseous benzene, benzene-d6, and their mixtures, particularly the formation process of C3H3+, have been investigated using ion cyclotron single- and double-resonance techniques. Double-resonance experiments demonstrated that C3H3+ is formed by the ion-molecule reaction: C6H7++C6H6→C3H3++neutral product. In C6H6–C6D6 mixtures, not only C3H3+ but also deuterium substituted ions, such as C3H2D+ and C3HD2+, are formed from C6H7+. Quantitative analysis of the double-resonance intensity revealed that C3H3+ is formed by the decomposition of the intermediate complex of [C6H7+–C6D6], which is a σ-type complex.
CNDO/2 Calculations of Ionization Potentials of Some Fluorosubstituted Conjugated Hydrocarbons
Authors: Hayashi Toshio , Nakajima Takeshi 
Published: July 2006

Abstract
The ionization potentials of the fluorosubstituted derivatives of ethylene, trans-1,3-butadiene, and benzene were calculated by using the modified CNDO/2 method. In agreement with the available experimental facts, the ionization potentials due to the π-electron were predicted to change little on fluorination, while those due to the σ-electron were predicted to suffer a more or less large change on fluorination. An explanation for this fact, called the perfluoro effect, can be given by a simple perturbational treatment.
MO-theoretische Untersuchung der Nucleophilen Substitution Einiger Silacycloalkane
Authors: Frenking Gernot , Kato Hiroshi , Fukui Kenichi 
Published: July 2006

Abstract
CNDO/2 calculations have been carried out for (CH2)n−1SiMeH and (CH2)n−1CMeH with n=3, 4, 5, and 6. It is found that the electronic structure of the two classes of compounds shows principal differences in the ringsize dependence. It is suggested that this is the reason for the different ring dependence of the reactivity in the nucleophilic substitution reaction.
The Synergistic Extraction of Cobalt Ion Fixed on the Ion Exchange Resin with a Mixture of 2-Thenoyltrifluoroacetone and Pyridine Bases
Authors: Tamura Tooru , Ohzeki Kunio , Kambara Tomihito 
Published: July 2006

Abstract
The extraction of cobalt(II) on the ion exchange resin into a mixture of 2-thenoyltrifluoroacetone(Htta) with pyridine bases in various organic solvents has been studied. In the presence of pyridine bases(B), cobalt ions were extracted from the resin into the organic phase in the form of base adducts, Co(tta)2Bn. The synergistic effect decreased in the order: pyridine&gt;β-picoline&gt;γ-picoline&gt;α-picoline&gt;γ-collidine\simeqisoquinoline\simeqpiperidine&gt;4-benzoylpyridine. This trend was related to its structure, particularly the steric effect of the ortho-substituent.
Impurity Metal-Activated Crystal Growth of Niobium Monophosphide from Gas Phase
Authors: Motojima Seiji , Izushi Toyohiko , Sugiyama Kohzo , Takahashi Yasutaka 
Published: July 2006

Abstract
Niobium monophosphide single crystals were obtained by chemical vapor deposition from a gas mixture of NbCl5, PCl3, H2, and Ar on a quartz substrate using metallic impurity. The existence of Au, Pt, Pd, and Ni resulted in the growth of whiskers or pillar crystals. Maximum whisker length of 5 mm and thickness of 30 μm were obtained at 1150 °C for an hour with the use of Pt impurity. Platelet crystals (400×1000×20 μm, max.) were obtained with the use of Pt at 1240 °C. The growth directions of the whiskers and some platelet crystals were assigned to 〈001〉 and a direction in (001) plane, respectively. The optimum growth conditions for the pillar crystals in the case of Ni impurity: substrate temperature 1000–1020 °C, gas flow ratio PCl3/(NbCl5+PCl3) of 0.7–0.75. From observation of the tip and base of pillar crystals grown with Ni, the growth mechanism seems to be base VLS followed by VS.
The Extraction Spectrophotometric Determination of Palladium with Monothiodibenzoylmethane
Authors: Prabhu B N , Khopkar S M 
Published: July 2006

Abstract
Monothiodibenzoylmethane (HSDBM) was used for the quantitative extraction of palladium. It was extracted at pH 3.5–6.5, with 0.001 M HSDBM in benzene, as an orange-red colored complex and measured spectrophotometrically at 470 nm. Beer’s law was valid in the concentration range of 0.6 to 3.6 μg of palladium per ml. The complex was stable for at least 144 h. Ten milliliters of 0.001 M HSDBM in benzene was adequate for quantitative extraction of palladium. The optimum period of equilibration was 10 min. It was possible to extract palladium in the presence of a large number of elements.
Melting and Solid–Solid Transition Temperatures at High Pressures for NH4SCN, RbSCN, T1SCN, and CsSCN
Authors: Klement William 
Published: July 2006

Abstract
Differential thermal analyses at high pressures have yielded the following trajectories for melting and solid–solid transitions in the several thiocyanates: (substance, transition, 1-bar transition temperature in °C, initial slope (dT/dp) in deg kbar−1, initial curvature (–d2T/dp2) in deg kbar−2, approximate maximum pressure in kbar) NH4SCN, melting, ≈146, ∼20 (tentative), –, ∼3.5; NH4SCN, (upper) solid–solid, 120±4, 12.6±1.5, –, 7.5; RbSCN, melting, 184±2, 15.7±0.3, 0.32±0.05, 36; RbSCN, solid–solid, 166±3, 13.5±1.0, 0.3±0.1, 30; TlSCN, melting, ≥234, ≥10 (tentative) &gt;0, 34; TlSCN, solid-solid, 99±2, 9.6±1.0, ≈0.17, 34; CsSCN, melting, ≥206, ≈14±1.5, ∼0.2–0.4, 33; CsSCN, solid-solid, ≥197, ≈11.8±1.0, ∼0.2, 33. The solid–solid transitions investigated here for NH4SCN, RbSCN and T1SCN appear to be closely-related, structurally, to the well-investigated transition in KSCN. The thermodynamics of the KSCN transition at 1-bar is discussed anew so as to be consistent with high pressure data. The transitions in these other thiocyanates are probably thermodynamically similar to the KSCN transition but the necessary data to establish the similarities are lacking. Lattice parameters for NH4SCN and RbSCN show rapid variations with temperature below the solid–solid transition, as for KSCN. DSC and DTA results are presented for the 1-bar transition temperatures and entropy changes for NH4SCN, RbSCN, TlSCN, CsSCN and also AgSCN. The entropy changes apparently associated with the structurally similar solid–solid transitions decrease with increasing cation polarizability.
The Electronic Spectra of Some Phenylthiophenes. A Molecular Orbital Treatment
Authors: Abu-Eittah R , Hilal R 
Published: July 2006

Abstract
The electronic absorption spectra of the thiophene derivatives: mono, di-, and poly-phenylthiophenes are studied in both polar and non-polar solvents. The interaction between thienyl and phenyl chromophores is investigated both experimentally and theoretically. Assuming planar and perpendicular conformers, molecular orbital calculations are carried out on 2-phenylthiophene and on 3-phenylthiophene using the Localized-Orbital Model. The results show: (i) the planar conformer is more adquate than the perpendicular one, (ii) the near UV spectra of the two isomers are similar though their degree of conjugation is different, and (iii) excited states arise from substantial configuration interaction. There is a good agreement between the observed and calculated spectra of the two isomers.
Proton Magnetic Resonance Study of Poly(p-chlorostyrene) of Low Molecular Weight
Authors: Hirai Yoshiyuki , Nunomura Yoshio , Imamura Yoshio 
Published: July 2006

Abstract
Poly(p-chlorostyrne) samples of relatively low molecular weight (average degrees of polymerization (‾DP): 15, 24, and 46) were prepared by radical polymerization and their PMR spectra were observed in the temperature range 5–88 °C. When the temperature was elevated, the absorption of the methyne proton moved to lower field and the half height width for the absorption of the ortho proton decreased more remarkably than that of the meta proton. The absorption of the ortho proton of one polymer sample (‾DP: 15) showed an anomalous broadening. These features of the observed spectra were interpreted in terms of ring current shielding by aromatic side groups, and the conformations of the polymer are discussed.
Studies on 1,2,4-Thiadiazolidine Derivatives. I. The Synthesis and Structural Determination of 2,4-Disubstituted 3,5-Disubstituted Imino-1,2,4-thiadiazolidines
Authors: Kinoshita Takeshi , Sato Sadao , Tamura Chihiro 
Published: July 2006

Abstract
The reaction of symmetrical thiourea derivatives, RNHCSNHR, with benzoyl peroxide (BPO) gave only one isomer of 2,4-disubstituted 3,5-disubstituted imino-1,2,4-thiadiazolidines, and that of nonsymmetrical thiourea derivatives, RNHCSNHR′, with BPO yielded a mixture of some of the possible isomeric derivatives. The structures of these compounds were determined by means of NMR, mass spectra, and X-ray analyses. The steric effects of peripheral groups around the thiadiazolidine ring and some reaction mechanism are discussed.
Studies of Sulfonyl Radicals. III. Solvent Effects on the Thermal Decomposition of Benzyl Phenylazo Sulfone
Authors: Iino Masashi , Yanagisawa Tateo , Takahashi Yozo , Matsuda Minoru 
Published: July 2006

Abstract
The first-order rate constants for thermal decomposition of benzyl phenylazo sulfone (BPA, 1) have been determined spectrophotometrically in six solvents using the free radical scavenging technique with a stable Koelsch free radical. Activation parameters in the non-polar solvents such as benzene, toluene, anisole and chlorobenzene were almost the same, but in the two polar solvents, pyridine and nitrobenzene, activation entropies decreased significantly as compared with those in the non-polar solvents. This can be explained by the solvation of the polar solvent in the transition state leading to a phenyldiazenyl and α-toluenesulfonyl radical pair.
The Reaction of Organoboranes with d-Carvone and l-Perillaldehyde in the Presence of Oxygen. Evidence for a Coordination between Organoboranes and α, β-Unsaturated Carbonyl Oxygens in Their Oxygen-Induced Free Radical Reaction Process
Authors: Arase Akira , Masuda Yuzuru , Suzuki Akira 
Published: July 2006

Abstract
Oxygen-induced 1,4-addition reactions of trialkylboranes with cyclic α, β-unsaturated carbonyl compounds were studied. Stereoselective 1,4-additions of the alkyl groups of trialkylboranes were observed in the reactions of d-carvone and l-perillaldehyde. Namely, it was shown that the alkyl group adds to d-carvone from the trans side with respect to isopropenyl group to give the corresponding saturated ketones. The same type of one side attack of the alkyl group to l-perillaldehyde was also observed. The evidence seems to strongly support the hypothesis that coordination of boron atoms of trialkylboranes to carbonyl oxygens plays an important role, even in the oxygen-induced free radical chain reaction of organoboranes with α, β-unsaturated carbonyl compounds.
A Synthesis of Diosphenols
Authors: Ohashi Masao , Inoue Seiichi , Sato Kikumasa 
Published: July 2006

Abstract
A new synthesis of diosphenols (1 and 2) is described. The oxidation of 2-isopropylcyclohexanone with copper(II) chloride gave the corresponding α-diketone (8), which was then methylated to afford diosphenol (1) together with a considerable amount of isodiosphenol (2). In particular, pure 2 has been isolated and the characteristics of 2 are also presented.
The Abnormal Wallach Rearrangements of 4,4′-Dialkylazoxybenzenes
Authors: Shimao Ichiro , Matsumura Shigenori 
Published: July 2006

Abstract
The reactions of 4,4′-dialkylazoxybenzenes (1) with sulfuric acid afforded 2-alkyl-5-(p-alkylphenylazo)phenols (2) and 2-alkyl-4-(p-alkylphenylazo)phenols (3) as novel rearrangement products; in certain cases 4-(p-alkylphenylazo)phenols (4) were also obtained. The ratios of these azophenols were greatly affected by the alkyl group type. In addition, the reactions gave a very small amount of 5-alkyl-2-(p-alkylphenylazo)phenols (5), which were considered as normal Wallach rearrangement products.
The Facile Synthesis of N-Substituted Piperidines from Glutaraldehyde and Primary Amines with Tetracarbonylhydridoferrate
Authors: Watanabe Yoshihisa , Shim Sang Chul , Mitsudo Take-aki , Yamashita Masakazu , Takegami Yoshinobu 
Published: July 2006

Abstract
Ethanolic tetracarbonylhydridoferrate solution combined with glutaraldehyde is very efficient for the selective transformation of an amino group into a piperidine ring. A large variety of both aliphatic and aromatic amines react with the ferrate-glutaraldehyde at room temperature under carbon monoxide to give the corresponding N-alkyl- and N-arylpiperidines in good to excellent yields.
Dehydroannulenes. V. Synthesis and Properties of 1,6,12,17-Tetra-t-butyl-2,4,13,15-tetrakisdehydro[22]annulene
Authors: Iyoda Masahiko , Miyazaki Hideaki , Nakagawa Masazumi 
Published: July 2006

Abstract
The synthesis of 1,6,12,17-tetra-t-butyl-2,4-13,15-tetrakisdehydro[22]annulene has been performed. The tetrakisdehydro[22]annulene was found to be strongly diatropic having high conformational stability.