bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phenanthro[4,5-bcd]furan Derivatives. I. A Synthesis of 5-Hydroxy-1-methoxyphenanthro[4,5-bcd]furan
Authors: Shimizu Takahachi , Horaguchi Takaaki , Watanabe Akio 
Published: July 2006

Abstract
5-Hydroxy-1-methoxyphenanthro[4,5-bcd]furan(I;R=MeO) was synthesized by dehydrogenation with 20% palladium on charcoal from 5,6,7,7a,8,9-hexahydro-1-methoxy-5-oxophenanthro[4,5-bcd]furan(XVII), which had itself been prepared via a naphthofuran derivative (XVI) starting from 5,8-dimethoxy-1-tetralone (VII).
Racemization Reactions of Cobalt(III) Complexes of Ethylenediaminetetraacetate and Trimethylenediaminetetraacetate
Authors: Ogino Hiroshi , Takahashi Masatake , Tanaka Nobuyuki 
Published: July 2006

Abstract
The kinetics of racemization reactions of ethylenediaminetetraacetatocobaltate(III), CoIIIedta−, and trimethylenediaminetetraacetatocobaltate(III), CoIIItrdta−, were investigated in acid solutions. The rate law for the racemization of (+)546CoIIIedta− is:
\fracd[(+)546CoIIIedta−]dt=−2\frackr1Ka+kr2[H+]Ka+[H+][(+)546CoIIIedta−]
where Ka is the equilibrium constant of the reaction:
(+)546CoIII(H2O)Hedta\ightleftarrows(+)546CoIIIedta−+H+
The values of kr1 and kr2 at 120°C and at an ionic strength of 0.53 are 2.0×10−5 sec−1 and 5.6×10−4 sec−1 respectively. The rate law for the racemization of (+)589CoIIItrdta− is:
\fracd[(+)589CoIIItrdta−]dt=−2k′r2[H+][(+)589CoIIItrdta−]
The value of k′r2 at 120°C and at an ionic strength of 0.53 is 1.9×10−5 l mol−1 sec−1. It is known that the rate of the racemization reaction of optically-active CoIIedta2− is accelerated by the presence of CoIIedta2− because of the electron-exchange reaction between these two species. In this paper, the electron-exchange reaction between CoIIItrdta− and CoIItrdta2− is also investigated by the utilization of the optical activity. This reaction proceeds faster than the reaction between CoIIIedta− and CoIIedta2−.
One-Electron Reduction of Carbonium Ions. IV. A Kinetic Study on the Reduction of the Substituted Tropylium Ions with Cr(II)
Authors: Okamoto Kunio , Komatsu Koichi , Murai Osamu , Sakaguchi Osamu , Matsui Yoshihisa 
Published: July 2006

Abstract
The one-electron reduction of the unsubstituted, methyl-, ethyl-, isopropyl-, t-butyl-, triphenylmethyl-, and phenyltropylium ions with Cr(II) in a 10% HCl solution gives, quantitatively, the dimer of the corresponding substituted tropyl radical. The measurements of the reaction rate at 25°C exhibit this order of reactivity: t-butyltropylium (k2=7.98 l/g·ion·sec), isopropyltropylium (8.22), ethyltropylium (10.3), methyltropylium (11.1), tropylium (74.0), phenyltropylium (144), and triphenylmethyltropylium (567) ions. The values of log k2 have a linear correlation with the transition energies of the charge-transfer bands observed for these carbonium ions with pyrene, and also with the polarographic half-wave potentials of the respective cations. These correlations indicate that the reactivity of the carbonium ion in the reduction with Cr(II) is determined mainly by the electron affinity inherent in the respective cations. The values of log k2 also have a good linear correlation with the pKR+ values, implying a parallelism between the electron affinity and the electrophilicity of these stable carbonium ions.
The Tautomeric Equilibria of 4-(Dialkylamino)azobenzene Derivatives
Authors: Yamamoto Shunzo , Nishimura Norio , Hasegawa Shigeo 
Published: July 2006

Abstract
The tautomeric equilibrium constants, Kt=[ammonium ion]/[azonium ion], of the first conjugate acids of 4-dialkylaminoazobenzene derivatives were estimated by the spectrophotometric method. The Kt values increase in this order: pyrrolidino- &lt;dimethylamino- &lt;diethylaminoazobenzenes. The effects of N-alkyl groups on the base strength of the amino and azo nitrogens were examined in order to explain the effects on the tautomeric equilibrium. The base strength of azo nitrogens is governed by the degree of the resonance interaction between the amino group and the rest of the molecule. For dimethylamino- and pyrrolidinoazobenzenes, the base strength of the amino nitrogen can also be explained in terms of the resonance effects, but the amino nitrogen of diethylaminoazobenzenes exhibits an anomalously high base strength, arising from the steric inhibition of the hydrogen bonding in the free base. The above order of Kt can be explained in terms of these cumulative resonance and steric effects.
Polyether-amides from the Condensation of ω-(p-Carboxyphenoxy)alkanoic Acids with Aliphatic Diamines
Authors: Kito Taketoshi , Fujimoto Tsutomu , Mikami Ryuzo , Hirao Ichiro 
Published: July 2006

Abstract
Polyether-amides were prepared by the polycondensation of ω-(p-carboxyphenoxy)alkanoic acids (CPAA) and such aliphatic diamines as ethylenediamine, hexamethylenediamine, and piperazine. The polymers with higher intrinsic viscosities and moderate melting temperatures (200–240°C) were obtained from CPAA and hexamethylenediamine. The polymers from both CPAA and ethylenediamine or piperazine generally have low intrinsic viscosities; the former melted at higher temperatures than did the polyether-amides with hexamethylenediamine, while the latter melted at lower ones.
Syntheses of Isoprenoids by Telomerizations. VIII. Anionic Telomerizations of Isoprene with Secondary Amines
Authors: Takabe Kunihiko , Katagiri Takao , Tanaka Juntaro 
Published: July 2006

Abstract
The anionic telomerizations of isoprene with secondary amines in the presence of alkali-metal catalysts were investigated under several conditions. The n=2 telomers were found to contain N,N-dialkyl(3,7-dimethyl-2,6-octadienyl)amine (2A) and N,N-dialkyl(2-isopropenyl-5-methyl-4-hexenyl)amine (2B) as the main components, n=1 and n=3 telomers were also identified. On the basis of these results, the mechanism of this anionic telomerization and the reactivity of the carbanions connected with this reaction were discussed.
Bond Distortions and Related Phenomena in Peri-Condensed Tetracyclic Nonbenzenoid Aromatic Hydrocarbons
Authors: Toyota Azumao , Nakajima Takeshi 
Published: July 2006

Abstract
On the basis of the second-order Jahn-Teller effect and SCF MO method, we have examined the geometrical structures with respect to bond length and the ground-state multiplicity and stability of peri-condensed tetracyclic nonbenzenoid aromatic hydrocarbons. It was found that of the molecules examined, dibenzo[cd, gh]pentalene (III) and its seven-membered analogue (IV) should have a triplet ground-state, exhibiting no appreciable double-bond fixation in the peripheral carbon skeleton. The other molecules were predicted to suffer the first-order or second-order bond distortions, showing a more or less marked double-bond fixation. The electronic spectra were calculated using the bond distances obtained on the basis of SCF MO method.
Photochemical Reactions of Aromatic Compounds. XI The Photochemical Cycloaddition of Vinyl Ethers to α-Naphthonitrile
Authors: Pac Chyongjin , Sugioka Taizo , Mizuno Kazuhiko , Sakurai Hiroshi 
Published: July 2006

Abstract
The photochemical reactions of α-naphthonitrile with vinyl ethers gave two stereo-isomeric (2+2) cycloadducts, trans-1-cyano-8-alkoxy-2,3-benzobicyclo[4.2.0]octa-2,4-diene 1 and the cis isomer, 2, in 80–90% yields. From the results of fluorescence measurements and kinetic analysis, the photocycloaddition was established to occur from the lowest excited singlet state of α-naphthonitrile.
The Liquid Membranes of the Thiocyanate Ion-Sensitive Electrode
Authors: Ishibashi Nobuhiko , Kina Kenyu 
Published: July 2006

Abstract
Ion-selective electrode membranes responsive to the thiocyanate ion were prepared by using ion-association extraction systems. A crystal violet or tetraphenylarsonium cation was used as an ion exchange-site in the liquid nitrobenzene membrane. The liquid membrane electrode exhibits an ideal Nernstian response to the thiocyanate ion down to 10−5 M. The selectivity of the liquid membrane largely depends on the extractability of the diverse anion into nitrobenzene. The order of the selectivity coefficients, Kj, is as follows:
ClO_4^-&gt;IO_4^-&gt;SCN^-&gt;I^-&gt;ClO_3^-&gt;NO_3^-&gt;Br^-&gt;BrO_3^-&gt;Cl^-
High selectivities for thiocyanate over SO42−, H2PO4−, Cl−, BrO3−, and Br were observed. The membrane potential is independent of the pH variation in the region from pH 2 to 12.
The Polymerization of Vinyl Monomers in the Presence of Surface Active Agents. III. The Rate of the Polymerization of Styrene
Authors: Asahara Teruzo , Sen\={o} Manabu , Shiraishi Shinsaku , Arita Yoshikazu 
Published: July 2006

Abstract
Styrene polymerized in the presence of sodium tetrapropylenebenzenesulfonate in an aqueous system without any ordinary initiators. The rate of the polymerization was dependent on the concentration of the surfactant and on the initial monomer concentration. The apparent activation energy of the polymerization was about 13.9 kcal/mol. The polymerization was inhibited by adding hydroquinone to the reaction system.
Studies on the Synthesis of Furan Compounds. XXX. Syntheses and Steric Configurations of 3-(5-Nitro-2-furyl)-2-(5-bromo-2-furyl)acrylic Acid and Its Related Compounds
Authors: Hirao Ichiro , Kato Yasuhiko , Kozakura Shiro 
Published: July 2006

Abstract
cis- and trans- 3-(5-Nitro-2-furyl)-2-(5-bromo-2-furyl)acrylic acids (II and III) and their functional derivatives have been synthesized in connection with the syntheses and steric configurations of 3-(5-nitro-2-furyl)-2-(5-bromo-2-furyl)acrylonitrile and its related compounds. The treatment of cis-3-(5-nitro-2-furyl)-2-(2-furyl)-acrylic acid (I) with bromine in refluxing carbon tetrachloride afforded a 1 : 1 mixture of II and III in quantitative yield. II and III afforded methyl (IV and VI) and ethyl (V and VII) esters, via each acid chloride (VIII or IX) by treatment with methanol and ethanol, respectively. Similarly, cis- and trans-3-(5-nitro-2-furyl)-2-(5-bromo-2-furyl)acrylamides (X and XI) were obtained by treatment of VIII and IX with dry ammonia in benzene. Isomerization was observed in the conversion of X into trans-3-(5-nitro-2-furyl)-2-(5-bromo-2-furyl)acrylonitrile (XII) upon treatment with phosphoryl chloride, while XI maintained its configuration under similar conditions to afford XII. On the other hand, cis-acid and esters (II, IV, and V) were converted into the corresponding trans isomers (III, VI, and VII) respectively, by treatment with hydrazine hydrate in refluxing methanol. II was confirmed to be isomerized to III by heating with hydrochloric acid or by irradiation with ultraviolet light (406 mμ). The structures and configurations of these compounds were discussed on the basis of their IR and NMR spectra.
Studies of the Molybdenum Catalysts. Part I. Changes in the State of the Hydrated Molybdenum Oxide Catalyst during a Reaction between Thiophene and Hydrogen
Authors: Sotani Noriyuki , Hasegawa Masatomo 
Published: July 2006

Abstract
The reaction between thiophene and hydrogen on hydrated molybdenum oxide was studied. Structural and compositional changes in the catalyst were found during the hydrodesulfurization of thiophene. The main products of the reaction were n-butane, butenes, and hydrogen sulfide. The conversion of thiophene increased with the progress of the reaction and reached a steady value after passing through a maximum. This reaction process was distinguished into two stages. One is the “aging stage,” and the other is the “stationary stage.” At the aging stage, three reactions, that is: i) dehydration, ii) reduction, and iii) sulfurization occur. The catalyst reacts with the reactants and changes in structure and composition. Hydrated molybdenum oxide was converted to MoO3 by liberating the structural water, and MoO3 was reduced to MoO2. A part of the MoO3 was also sulfurized directly with thiophene to MoS2 during the aging stage, but MoO2 could not easily be sulfurized. At the stationary stage, no further change in the catalyst was found, and only the catalytic hydrodesulfurization of thiophene occurred. The conversion at the stationary stage, when the aging temperature was low, was larger than the conversion at a high temperature. The difference between the conversions at different reaction temperatures was assumed to result from the structural and compositional changes in the catalyst caused by the different temperatures of the aging processes. In this reaction, the dehydration at the aging stage controls the activity of the catalyst.
Photochemical Reactions of Enamino Ketones
Authors: Yamada Kazutoshi , Konakahara Takeo , Iida Hirotada 
Published: July 2006

Abstract
Photochemical reactions of N-aryl enamino ketones including one enone system and one divinylamine system in the molecule were examined. Photochemical behaviours of N-aryl enamino ketones differed for the tertiary and secondary amines involved. While 5,5-dimethyl-3-(N-methylanilino)cyclohex-2-en-1-one gave an oxidative cyclization product, 3-anilino-5,5-dimethyl-cyclohex-2-en-1-one gave two major products and a minor one. One of the major products was characterized as 3,3-dimethyl-5-hydroxy-3,4-dihydro-1-benzazocines by their elemental analyses and spectroscopic properties. The compounds showed 6π system pseudo aromaticity in their NMR spectra. The temperature-dependent NMR signals for gem-dimethyl protons were due to the flapping of the 8-membered ring. The reduction product with diborane was identified as 1,2,3,4,5,6-hexahydro-1-benzazocine by comparison with an authentic sample. The other major product was a ketene adduct and the minor product, a lactone.
The Prins Reaction of Cyclooctene and Cyclododecene
Authors: Uchida Akira , Maeda Toyohiro , Matsuda Sumio 
Published: July 2006

Abstract
The reaction products of the sulfuric acid-catalyzed condensation of cyclooctene or cyclododecene with formaldehyde in acetic acid at 40 °C were investigated. The reaction of cyclooctene gave a mixture of 4,5-hexa-methylene-1,3-dioxane, 2-cyclooctenylmethyl acetate, and 1-acetoxy-2-acetoxymethylcyclooctane, while reaction of cyclododecene gave a mixture of cyclic ethers; one was identified as 3-oxabicyclo[10,3,0]-6-pentadecene, and the others were estimated to be 15-acetoxy-3-oxabicyclo[9,3,1]pentadecane and 12,17-dioxatricyclo[13,3, 0,010,14]-2-octadecene.
Effects of N-Acyl- and N-s-Triazinyl Groups on the Rearrangement of S-(s-Triazinyl)-2-aminothiophenols and O-(s-Triazinyl)-2-aminophenols
Authors: Shiojima Takeo , Kuroda Toshio , Ohkawa Sohei , Hasegawa Yasushi , Matsui Kohji 
Published: July 2006

Abstract
S-s-Triazinyl-2-aminothiophenols (I) containing methoxyl and/or dimethylamino groups in the S-triazine nucleus gave disulfides of N-s-triazinyl-2-aminothiophenols upon the S→N migration of the s-triazinyl group in the presence of acid; the rate of S→N migration was slow compared to that of the O→N migration of the corresponding O-s-triazinyl-2-aminophenol. On acylation or s-triazinylation, S-dimethoxy-s-triazinyl-2-aminothiophenol (I–1) and O-dimethoxy-s-triazinyl-2-aminophenol (II-1) gave N-acyl-N-s-triazinyl- or N,N-bis (s-triazinyl) derivatives upon the S→N or O→N migration of the s-triazinyl group. However, S-dimethylaminomethoxy-s-triazinyl-2-aminothiophenol (I–2), S-bis[(dimethylamino)-s-triazinyl]-2-aminothiophenol (I–3) and the corresponding derivatives of o-aminophenol gave N-acyl- or N-s-triazinyl derivatives, wihtout any migration of the s-triazinyl group, by acylation or s-triazinylation. The facility of the rearrangement of these N,S-bis-(s-triazinyl)-2-aminothiophenols and N,O-bis(s-triazinyl)-2-aminophenols depended not only upon the substituents in S- or O-s-triazine nucleus, but also upon the substituents in the N-s-triazine nucleus; the substituents in the N-s-triazine nucleus of strong electron-attracting and of strong electron-donating substances were not appropriate for the rearrangement in the presence of alkali to give disulfides of N-s-triazinyl-2-aminothiophenols (III–I) or N-s-triazinyl-2-aminophenols (III–II).
Chemical Evidence for the Existence of pπ-dπ Interaction between the Unsaturated Bond and the Sulfur Atom in Allyl and Vinyl Sulfide Systems
Authors: Ojima Iwao , Kondo Kiyosi 
Published: July 2006

Abstract
Chemical evidence for the activation of double bonds by the use of 3d orbitals of the sulfur atom was observed in the reaction of allyl benzyl sulfide and phenyl vinyl sulfide with diazomethane. Similar supporting evidence was also obtained in the reaction of acetophenone tosylhydrazone with allyl benzyl sulfide in the presence of sodium methoxide at 150 °C. It was found that there should not be any important role of the oxygen atom of allyl benzyl ether in directing the orientation of the 1,3-dipolarophile.
Intramolecular Interaction between the Hydroxyl Group and the Oxirane Ring
Authors: \={O}ki Michinori , Murayama Tetsuo 
Published: July 2006

Abstract
The intramolecular interaction between the hydroxyl group and the oxirane ring has been detected by means of studying the infrared spectra in the 3μ region of various hydroxyalkyloxiranes. The O–H stretching absorptions of several compounds which have limiting structures in the sence of the conformational preference have been closely examined. The results indicate that the intramolecular interaction takes place between the hydroxyl group and the electron orbitals involved in the formation of the C–O bond, while that involving the electrons of the C–C bond can be neglected.
Macro Rings. V. Syntheses of Tetraoxaparacyclophanes Containing Two Biphenyl Nuclei
Authors: Nishikido Joji , Inazu Takahiko , Yoshino Tamotsu 
Published: July 2006

Abstract
Three new tetraoxaparacyclophanes containing two biphenyl nuclei connected with oxypolymethyleneoxy bridges in the respective 4,4′-positions, such as 1,5,18,22-tetraoxa[5.0.5.0]paracyclophane I3, 1,6,19,24-tetraoxa-[6.0.6.0]paracyclophane I4, and 1,7,20,26-tetraoxa[7.0.7.0]paracyclophane I5, were synthesized. The UV, IR, and NMR spectra of these paracyclophanes were compared with those of the corresponding open-chain compound, IV3.
Syntheses of l-Threose and Methyl Di-O-acetyl-l-threuronate from dextro-Tartaric Acid
Authors: Nakaminami Gen , Edo Haruo , Nakagawa Masazumi 
Published: July 2006

Abstract
Reduction of methyl hydrogen di-O-acetyl-dextro-tartrate (I) with sodium borohydride in water afforded l-threono-γ-lactone (II). l-Threose (IV) was obtained on treatment of the γ-lactone (II) with an excess of disiamylborane. Reduction of ester chloride of di-O-acetyl-dextro-tartaric acid (VI) with tri-n-butyltin hydride yielded methyl di-O-acetyl-l-threuronate (VII). Attempts to reduce 2-deoxy-pentarate ester (X) derived from ester chloride (VI) via diazoketone (VIII) with sodium borohydride to give 2-deoxy-threo-pentono-γ-lactone (XI) gave unsatisfactory results. Formation of methyl l-threo-2,3-di-O-acetyl-5-chloro-5-deoxy-4-C-hydroxymethyl-4,4′-anhydropentonate (IX) in addition to diazoketone (VIII) was observed when ester chloride (VI) was treated with an excess of diazomethane. On the basis of the observed (−)-Cotton effect in the 290 nm region of ORD and CD spectra of l-threose (IV) and d-erythrose, possibility of the presence of an open chain non-hydrated alde-hyde-form of aldotetrose in water was discussed.
The Peracid-oxidation of Tetraphenylallene: The Formation of Hydroxyindanone and Its Oxidative Transformation
Authors: Oku Akira , Shimada Kojiro , Mashio Fujio 
Published: July 2006

Abstract
The oxidation of tetraphenylallene (1) with m-chloroperbenzoic acid has been reported. Under acidic conditions, 1-hydroxy-1,3,3-triphenyl-2-indanone (2) was isolated in 45% yield, along with benzophenone (3) and the m-chlorobenzoate of 2 as minor products. In the presence of sodium carbonate, the oxidation products were 2,2,4,4-tetraphenyloxetanone (6), 3, and 1,3,3-triphenyl-2,3-dihydro-5H-indene-2,5-dione (5). The prolonged oxidation of 2 with per ace tic acid yielded α,α-diphenylphthalide (9a). The alkaline hydrolysis of 2 induced ring cleavage to give o-benzhydrylbenzilic acid (15b), whereas acid hydrolysis in ethanol or methanol gave the corresponding ethers, 16a and 16b respectively.
Selective Homogeneous Hydrogenation of 3-Oxo-1,4-diene Steroids. II. Effects of Basic Additives and of para Substituents on the Hydrogenation with Dichlorotris(triphenylphosphine)ruthenium
Authors: Nishimura Shigeo , Ichino Tomio , Akimoto Akira , Tsuneda Kiyoshi 
Published: July 2006

Abstract
The catalytic homogeneous hydrogenation of 1,4-androstadiene-3,17-dione (I) with dichlorotris(triphenylphosphine) ruthenium has been investigated in the presence of basic additives. The rate of hydrogenation increased with respect to added amines in the order pyridine&lt;none&lt;butylamine&lt;aniline&lt;diethylamine≅triethylamine. The hydrogenation was also promoted by the addition of calcium carbonate, but slightly retarded by that of sodium carbonate. The amount of triethylamine required for obtaining the maximum rate of hydrogenation has been determined. Addition of triethylamine also reduced the formation of 5α-androstane-3,17-dione produced by a different pathway from that for the formation of 4-androstene-3,17-dione (II), resulting in an increased selectivity for the formation of II. I was also hydrogenated with the ruthenium complexes having p-methoxy-, p-methyl-, and p-fluoro-substituted triphenylphosphines as ligands. The catalytic activity of the ruthenium complex was greatly enhanced by p-methoxyl and p-methyl groups and reduced by p-fluoro group when the catalyst was used in the presence of triethylamine.
Studies of Enamines. II. The Reaction of 4-(1-Piperidyl)- and 4-(1-Pyrrolidinyl)-3-penten-2-ones with Aryl Isocyanates
Authors: Tsuge Otohiko , Inaba Akitaka 
Published: July 2006

Abstract
The reaction of aryl isocyanates with enamino ketones, derived from acetylacetone and secondary amines such as piperidine and pyrrolidine, has been investigated. At room temperature, enamino ketones react with phenyl, p-chlorophenyl and p-tolyl isocyanate to give 1:2 adducts, 3,5-diarylcarbamoyl derivative. In solution, these adducts exist in general as a mixture of two tautomers, 3-penten-2-one and 4-penten-2-one, the ratio depending on the solvent. Under reflux in benzene, the reaction of enamino ketones with phenyl isocyanate gives 4-amino-6-methyl-1-phenyl-5-phenylcarbamoylpyrid-2-one and its 3-phenylcarbamoyl derivative; the former is also obtained by heating the 1:2 adduct. On the other hand, 4-(1-pyrrolidinyl)-3-penten-2-one reacts with 1-naphthyl isocyanate to afford the 1:1 adduct, 5-(1-naphthylcarbamoyl)-4-penten-2-one.
Preparation of p-Nitrophenyl 2-O-Acetyl-β-d-glucopyranoside and N-Acetyl-β-d-glucosaminidase Activity toward It. (Essential Requirement of 2-Acetamide Group of Substrate for N-Acetyl-β-d-glucosaminidase Hydrolysis)
Authors: Yamamoto Kazuhiko 
Published: July 2006

Abstract
Paranitrophenyl 2-O-acetyl, and 2,3-di-O-acetyl-β-d-glucopyranoside (VI, VII) were synthesized in order to investigate the effect of the substitution of the amide-nitrogen of the substrate by oxygen on the N-acetyl-β-d-glucosaminidase hydrolysis. Paramethoxybenzylidene was used as an O-blocking group for the preparation, and it was found that this blocking group could be easilly removed without the destruction of p-nitrophenyl glycoside. The evidence that VI could not be hydrolysed with this enzyme indicated the essential requirement of the amide-nitrogen of the substrate for the enzyme action.