bluuebunny/crossref_metadata_2025 huggingface dataset:
The Crystal and Molecular Structure of dl-2-cis-4-trans-Abscisic Acid
Authors: Ueda Hideo , Tanaka Jiro
Published: July 2006

The crystal and molecular structure of dl-2-cis-4-trans-abscisic acid has been determined by the X-ray method. The crystal is monoclinic, P21/c, with lattice parameters a=6.316(1), b=33.575(3), c=7.607(1) Å, and β=118.42(1)°. The molecule has two independent conjugated systems forming respective planes which are orthogonal to each other. The molecules form a dimer by the hydrogen bonding and are connected by the other hydrogen bonding along the c-axis.
N-Alkylation of Nitrogen Heterocyclic Compounds with Dialkyl Phosphites
Authors: Hayashi Masahiro , Yamauchi Kiyoshi , Kinoshita Masayoshi
Published: July 2006

Dialkyl phosphites were found to be efficient alkylating agents for various nitrogen heterocyclic compounds, especially for imidazole analogs and pyridones, producing the corresponding N-alkyl derivatives.
Nucleoside Analogs. 4. Synthesis of 3′-Amino-3′-deoxyadenosine Analogs
Authors: Tadano Kin-ichi , Emori Yasufumi , Ayabe Mitsukuni , Suami Tetsuo
Published: July 2006

Three 9-(3-amino-2,4,5-trihydroxycyclopentyl)adenines and their N-acyl derivatives were prepared as carbocyclic analogs of 3′-amino and 3′-acetamido-3′-deoxyadenosine from the three diastereomers of diaminocyclopentanetriol and 4-amino-6-chloro-5-nitropyrimidine.
The Reactions of the Nitrogen Atom with Ethylene and Ethylene-d4
Authors: Takahashi Saku , Miyazaki Shozo
Published: July 2006

In the N–C2H4 system, the main final product was HCN, and the stoichiometry (ΔN/HCN) of the reaction was about 1.3. In the N–C2D4 system, CD2 and CD2N were found as the reactive intermediates. We suggested a mechanism different from that proposed by Herron.
Construction of a 3He Calorimeter and Heat Capacity Measurement of the 1965 Calorimetry Conference Copper Standard between 0.4 and 20 K
Authors: Arai Naoto , Sorai Michio , Suga Hiroshi , Seki Syûzô
Published: July 2006

Construction of an isoperibol-type calorimeter with a 3He cryostat is described. A system of charcoal-adsorption-pump is adopted. A Ge-thermometer used in the heat capacity measurements is calibrated in the temperature range from 0.4 to 1.5 K against the magnetic susceptibility of chromium potassium alum. The precision and the accuracy of the calorimeter is ascertained by the heat capacity measurement of the 1965 Calorimetry Conference Copper Standard (T-8.6) in the temperature range from 0.420 to 19.46 K. The deviation of the experimental points from the “copper reference equation” is within the experimental error of ±2.5% between 0.4 and 0.9 K, ±1.5% between 0.9 and 1.5 K, ±1.2% between 1.5 and 4 K, and ±0.6% between 4 and 20 K. The highest deviation of absolute value of the present heat capacity data of copper is 1.86% smaller than the “selected values (Furukawa et al.)” around 6 K. This difference may be primarily attributable to the NBS-65 temperature scale adopted in the present experiment.
Preparation and Stereochemistry of trans-Dianionocobalt(III) Complexes with (S)-2-(Methylaminomethyl)pyrrolidine
Authors: Kitamura Taku , Sato Yoshiko , Saburi Masahiko , Yoshikawa Sadao
Published: July 2006

trans-Dinitro and dichloro cobalt(III) complexes containing (S)-2-(methylaminomethyl)pyrrolidine (N-Me-ampr) were prepared. Their stereochemistry differs a great deal from that of other N-methylated 1,2-diamines. The N-Me-ampr complexes prefer the trans,cis instead of the trans,trans configuration, the axial N-methyl groups being fairly stabilized. In the case of the dinitro complex, only one isomer which has the axial N-methyl groups, was isolated, but in the case of the trans-dichloro complex two diastereomers (trans,cis(RR) and trans,cis(SS)) were obtained. These dichloro isomers were slowly converted into an equilibrium mixture in methanol. The CD spectral data of the equilibrium mixture show that the trans,cis(RR) is more stable than the trans,cis(SS) isomer (−ΔG=0.4 kcal/mol).
α,β-Unsaturated Carboxylic Acid Derivatives. XII. A Convenient Synthesis of Oxazole-4-carboxylic and 3,3-Dibromo-2,2-diamino Acids
Authors: Shin Chung-gi , Sato Yoshiaki , Sugiyama Hidetoshi , Nanjo Katsumi , Yoshimura Juji
Published: July 2006

Treatment of t-butyl 2-acetylamino-3-bromo-2-alkenoate with triethylamine gave t-butyl 5-alkyl-2-methyloxazole-4-carboxylate by dehydrobromination, but no reaction occurred with primary amines. While treatment of t-butyl 2-acetylimino-3,3-dibromoalkanoate with hydroxylamine or several aliphatic and aromatic primary amines gave addition products, t-butyl 2-acetylamino-3,3-dibromo-2-(hydroxyamino)- and 2-(substituted amino)alkanoate, respectively, in fairly good yields.
Oxidation of 2,6-Piperazinediones
Authors: Tanaka Tatsuo , Yamazaki Hiroaki , Ohta Masaki
Published: July 2006

1,4-Disubstituted 2,6-piperazinediones (1) are susceptible to oxidation at the methylene group in the piperazine ring, giving piperazinetetrone (4) on being treated with selenium dioxide in boiling dioxane. Treatment of 1,4-diphenyl-2,6-piperazinedione (1a) with either nitrobenzene or tosyl chloride and triethylamine in benzene gives cyclic dimer (9) of dehydrogenated 1a. Cycloadduct (10) is obtained in the presecne of N-phenylmaleimide. It seems that both 9 and 10 are formed via labile mesoionic intermediate (8). Piperazinedione (1a) reacted with tosyl chloride, pyridine, and benzoyl chloride to give mesoionic compound (11) having 3-benzoyl and 5-(p-tolylthio) groups.
Proton NMR Spectra and Conformations of N-Alkyl-N-benzyl-and N-Alkyl-N-(α-chlorobenzyl)carbamoyl Chlorides
Authors: Koyano Kinko , Suzuki Hiroshi , McArthur Colin R
Published: July 2006

Rotational isomerization about the amide C–N bond of twelve N-alkyl-N-benzylcarbamoyl chlorides (C6H5CHX–NR–COCl, 1: X=H, 2: X=Cl; R=CH3, C2H5, n- and i-C3H7, n- and t-C4H9) was studied by proton NMR spectroscopy. The values of ΔG\eweq for the isomerization are 15.8–17.3 kcal/mol for compounds 1 and 13.3–15.9 kcal/mol for compounds 2. Another kind of slow rotation was observed about the benzyl–nitrogen bond of 1(R=t-C4H9) and the α-chlorobenzyl–nitrogen bond of 2(R=CH3) at low temperature. The chiral centers of compounds 2 produce large nonequivalences for the geminal protons of the 2-methylene group of 2(R=n-C3H7) as well as 2(R=n-C4H9) and for the geminal methyl protons of 2(R=i-C3H7), reflecting some conformational preference of these compounds.
The σ-Bonded Palladium(II) Complex of 2-Pyridylferrocene
Authors: Kasahara Akira , Izumi Taeko , Maemura Mitsugi
Published: July 2006

2-Pyridylferrocene reacts with lithium tetrachloropalladate(II) in the presence of sodium acetate to give an ortho-palladated binuclear complex (4). The σ-bonded structure of 4 was confirmed by studies of the IR and NMR spectra and of the reactions of 4 with thallium (I) acetylacetonate and lithium aluminum deuteride. The reactions of 4 with carbon monoxide, butyllithium, and bromine were also examined.
The Titanium Trichloride-catalyzed Oxidation of Triphenylphosphine with Oxygen in Acetonitrile
Authors: Chimura Yasuo , Tarama Kimio
Published: July 2006

Titanium trichloride catalyzed very rapidly the oxidation of triphenylphosphine with oxygen in acetonitrile, yielding triphenylphosphine oxide and a yellow precipitate. The main catalytic cycle did not contain Cl3Ti–O–TiCl3 which was produced in the oxidation of TiCl3 alone, but the precursors of Cl3Ti–O–TiCl3 as intermediates. The yellow precipitate was a titanium(IV) complex with a discrete TiO group.
Polarographic Catalytic Currents Observed in Mixtures of Pb(II) and H2O2 in Neutral Solutions
Authors: Himeno Sadayuki
Published: July 2006

Normal pulse polarography has shown that the catalytic wave observed in neutral mixtures of Pb(II) and H2O2 is caused by Pb(OH)+ at the electrode surface, and that OH− ions are liberated in the vicinity of the electrode due to the catalytic reaction.
Spectroscopic and Kinetic Studies of the Photochromism of N-Salicylideneanilines and Related Compounds
Authors: Nakagaki Ryoichi , Kobayashi Takayoshi , Nakamura Junko , Nagakura Saburo
Published: July 2006

Photochromism of N-salicylideneanilines and related compounds was studied by measuring the electronic and vibrational spectra of the transient species. The rise time of the transient electronic spectra of the photochromic colored species was measured by picosecond time-resolved spectroscopy and was found to be dependent upon solvent viscosity. FT IR spectra showed that the photochromic colored species took the keto amine form. Picosecond kinetic analysis demonstrated that an intermediate existed in the transfer process from cis-keto amine to the photochromic species. These facts led us to the conclusion that the photochromic phenomenon of N-salicylideneanilines occurred through enol imine\oversethν→enol imine*→cis-keto amine*→the intermediate→trans-keto amine (photochromic species).
Reactivity of Excited Triplet Alkyl Ketones in Solution. I. Quenching and Hydrogen Abstraction of Triplet Acetone
Authors: Anpo Masakazu , Kubokawa Yutaka
Published: July 2006

The photolysis of acetone in various solutions has been investigated by analysis of reaction products as well as absorption spectroscopy. The rate of photolysis of acetone in aqueous solution decreases on addition of methanol or with increasing concentration of acetone, being much higher than that in methanol and heptane solutions. The results suggest that intermolecular hydrogen abstraction plays a significant role in quenching of triplet acetone. This is supported by spectroscopic studies which reveal formation of the enol form of acetone as an intermediate in the decay process of triplet acetone.
The Reactions of Sodium 1-Benzyl-1,4-dihydronicotinamide-4-sulfinate with Halogen Compounds
Authors: Inoue Hiroo , Inoguchi Nobuaki , Imoto Eiji
Published: July 2006

Sodium 1-benzyl-1,4-dihydronicotinamide-4-sulfinate (BNA-SO2Na) reacts with various halogen compounds, YZCHBr, through the cleavage of the carbon-sulfur bond to give sulfones, (YZCH)2SO2, in Y=Ph or PhCH=CH and Z=H; trans-stilbene in Y=Ph and Z=CH(Br)Ph or CH(OCH3)Ph; and the reduction products, YZCH2 and (YZCH)2, in Y=Ph, Z=Br, and Y=H, Z=PhCO. The BNA-SO2Na is converted to 1-benzylnicotinamide bromide, while sulfur dioxide or sulfite ions are formed.
Shock Tube Study on the Mechanism of Hydrogenation and Pyrolysis of Acetylene
Authors: Ogura Hiroo
Published: July 2006

Mixtures of acetylene and deuterium have been subjected to shock heating in a single-pulse shock tube in the temperature range 1000–1600 K. The reaction products were quite the same as those obtained from the pyrolysis of acetylene alone, with a considerable increase in the yields of the minor products. The predominance of 1-buten-3-yne formation and no appreciable dependence of its rate on the concentration of deuterium suggest that the initiation step is the same as that proposed in the pyrolysis of acetylene by itself, viz. 2C2H2→C4H3+H, the initiation step of the bimolecular reaction of C2H2 with D2 not being important. A complementary analysis of the isotopic distributions of 1-buten-3-yne, ethylene, and acetylene shows that hydrogenation also occurs by a free-radical chain mechanism, and the C4H3 radical and H atom generated by the initiation step are mainly responsible for the formation of 1-buten-3-yne and ethylene, respectively. The ethylene formation was of first-order in both acetylene and deuterium, and the second-order rate constant was obtained as

k(cm^3 mol^-1 s^-1)=(4.9±1.3)×10^11exp((-34900±600)/RT).
Synthesis of Corticotropin Peptides. XV. The Synthesis of an Undecapeptide and a Nonapeptide Derivatives Related to the Amino Acid Sequence 11–21 of Corticotropin
Authors: Inouye Ken , Watanabe Kunio
Published: July 2006

An undecapeptide derivative, Z–Lys(Mhoc)–Pro–Val–Gly–Lys(Mhoc)–Lys(Mhoc)–Arg–Arg–Pro–Val–Lys–(Mhoc)–NHNH2, corresponding to the amino acid sequence 11–21 of corticotropin (ACTH)is synthesized. In the course of the synthesis a key intermediate H–Arg(NO2)–Arg(NO2)–Pro–OH is derived from Z–Arg(NO2)–Arg–(NO2)–Pro–OBzl by the treatment with hydrogen bromide in acetic acid. This procedure eliminates the danger of racemization associated with the use of alkali for saponification. The synthesis is also described of a nonapeptide derivative, Z–Lys(Mhoc)–Pro–Val–Gly–Lys(Mhoc)–Lys(Mhoc)–Arg(NO2)–Arg(NO2)–Pro–OH (amino acid sequence 11–19 of ACTH), in which a new protecting group, 9-methyl-9-fluorenyloxycarbonyl (Mfoc), is utilized for the temporary protection of an α-amino function.
Substituent Effects on Dissociation Constants of trans-3-Hydroxy-6-styryl-4-pyrones
Authors: Besso Hiromichi , Imafuku Kimiaki , Matsumura Hisashi
Published: July 2006

The dissociation constants of 6-substituted 3-hydroxy-4-pyrones and trans-6-(substituted styryl)-3-hydroxy-4-pyrones were measured spectrophotometrically in 50% aqueous methanol at 25 °C. The results are correlated to the substituent constants σ, the following equations being obtained: pKa=8.57–1.53 σ and pKa=8.54–0.23 σ. The transmission coefficient through the styryl group was found to be 0.150 for the 3-hydroxy-6-styryl-4-pyrone system.
Stereochemistry of Cobalt(III) Complexes with Thioethers. I. Circular Dichroism Spectra of Complexes with Bi- or Terdentate Thioethers
Authors: Yamanari Kazuaki , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

Five (bidentate-N,S or -O,S)bis(ethylenediamine)cobalt(III) complexes have been optically resolved and their absolute configurations deduced from their circular dichroism (CD) spectra, where bidentate-N,S or -O,S are NH2(CH2)2S−, NH2(CH2)2SR (R=CH3 and C2H5), and CH3S(CH2)nCO2− (n=1 and 2). The chromatographic, CD, and NMR behaviors suggest that the thioether donor atoms are coordinated stereoselectively producing the Δ-(S) or Λ-(R) complexes. Three (terdentate-N,S,O)[1,1,1-tris(aminomethyl) ethane] cobalt(III) complexes of NH2(CH2)2SCH2CO2−, NH2(CH2)2S(CH2)2CO2−, and l-CH3SCH2CH(NH2)CO2− have been prepared and the complexes of the former two ligands optically resolved; the absolute configurations have been discussed on the basis of the CD spectra.
Circular Dichroism Spectra of Cobalt(III)–Ammine Complexes Containing Optically Active 1,3-Diphenyl-1,3-propanediamine or 1,2-Diphenyl-1,2-ethanediamine
Authors: Arakawa Sumio , Kashiwabara Kazuo , Fujita Junnosuke , Saito Kazuo
Published: July 2006

A series of optically active cobalt(III) ammine complexes containing (S,S)-1,3-diphenyl-1,3-propanediamine (dppn) or (S,S)-1,2-diphenyl-1,2-ethanediamine (stien) were prepared. The sign of circular dichroism (CD) of [Co(NH3)4(S,S-dppn)]Br3 depends on solvents in the first absorption band region. The CD magnitude of trans-[Co(NH3)2(S,S-dppn)2]3+ varies significantly with solvent variations in the same energy region. The CD curve of the vicinal effect of (S,S)-dppn derived from the two diastereomers of cis-[Co(NH3)2(S,S-dppn)2]3+ is different from the CD spectra of both [Co(NH3)4(S,S-dppn)]3+ and trans-[Co(NH3)2(S,S-dppn)2]3+. The CD spectra of the (S,S) -stien complexes are insensitive to solvent variations and the vicinal contributions of the (S,S)-stien calculated from a variety of the (S,S)-stien complexes are similar to one another.
Photolytic Oxidation of Alkylbenzenesulfonic Acids by Aqueous Sodium Hypochlorite
Authors: Nakamura Masao , Ogata Yoshiro
Published: July 2006

Photolyses of alkylbenzenesulfonic acids, such as benzene-, p-toluene-, and p-ethylbenzenesulfonic acids, in aqueous solution by sodium hypochlorite have been studied. In the presence of a large excess of hypochlorite, benzenesulfonic acid is completely photolyzed to give carbon dioxide and sulfuric acid. Irradiation of an equimolar mixture of substrate and hypochlorite in an aqueous solution yields the corresponding alkylbenzene, alkylphenol, arylalkyl alcohol and arylalkylaldehyde, some of which may be produced by an attack of the oxidant on alkyl chain. In some cases, small amounts of diaryl sulfones and chlorinated compounds are also detected.
Variations in the Vibrational Structures of Fluorescence Spectra of Naphthalene and Pyrene in Water and in Aqueous Surfactant Solutions
Authors: Nakajima Akira
Published: July 2006

Variations in the vibrational structures of the fluorescence spectra of naphthalene and pyrene in water and in aqueous solutions of sodium dodecyl sulfate (SDS) have been studied by comparison with those in various organic solvents. The results were applied to the determination of the critical micelle concentration of SDS.
Formations and Reactions of Cation Radicals from Compounds Possessing a p-Dimethylaminophenyl Group by Reactions with o-Sulfobenzoic Anhydride
Authors: Nagai Toshikazu , Shingaki Tadao , Yamada Hirokazu
Published: July 2006

It was found that cation radicals were formed from a number of substrates bearing a p-dimethylaminophenyl group, such as N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) and N,N,N′,N′-tetramethylbenzidine (TMB), by reactions with o-sulfobenzoic anhydride (o-AH). The systems, bis(p-dimethylaminophenyl)methane (BMM) and tris (p-dimethylaminophenyl) methane (TMM) with o-AH, gave their cations in the presence of oxygen, showing that the oxygen eliminates the hydrogen atoms of the cation radicals derived from BMM and TMM. The reactions of N,N-dimethylaniline (DMA) with o-AH gave rise to isolations of BMM and N-methylaniline, along with the formations of the cation radical of TMB and the crystal violet cation (TMM+). The mechanisms of the reactions are proposed.
Conversion of Cobalt(II) and Nickel(II) Fixed on the Ion Exchange Resin into Their Trifluoroacetylacetonates and Gas Chromatography of the Chelates
Authors: Tamura Tooru , Ohzeki Kunio , Kambara Tomihito
Published: July 2006

The conversion of cobalt(II) and nickel(II) ions collected on the ion exchange resin into the chelate compounds with trifluoroacetylacetone (Htfa) has been studied in various solvents. In the presence of pyridine, cobalt and nickel ions were quantitatively extracted from the resin into organic phase in the form of the base adducts [Co(tfa)2(py)2] and [Ni(tfa)2(py)2], respectively. The thermogravimetric and gas chromatographic behaviors of these compounds have been investigated. A gas chromatographic separation of [Ni(tfa)2] from [Co(tfa)2] was successfully performed.
1,3-Dipolar Cycloadditions to Bicyclic Olefins. I. 1,3-Dipolar Cycloadditions to Norbornadienes
Authors: Taniguchi Hisaji , Ikeda Toshikazu , Yoshida Yoshihiro , Imoto Eiji
Published: July 2006

The 1,3-dipolar cycloadditions of phenylglyoxylonitrile oxide, benzonitrile-N-phenylimine, or N-phenyl-C-p-nitrophenylnitrone to norbornadiene, 2,3-dicyanonorbornadiene, and 2,3-bis(methoxycarbonyl)norbornadiene give the endo-adducts, together with the exo-adducts. These findings show that the 1,3-dipolar cycloadditions to norbornadienes do not follow the “exo rule.” It is suggested that the present 1,3-dipolar cycloadditions are kinetically controlled reactions. The endo-side of norbornadienes is found to be homoconjugated by their NMR spectra. The homoconjugation must be responsible for the observed phenomenon.
Copper-initiated Decomposition of N,N-Dichloromethanesulfonamide
Authors: Torimoto Noboru , Shingaki Tadao , Nagai Toshikazu
Published: July 2006

The reactions of N,N-dichloromethanesulfonamide (I) with substrates such as hydrocarbons and ethers gave the N-substituted methanesulfonamide (II) and methanesulfonamide (III) in the presence of copper. The reaction with 2-methylbutane gave the product only with a tertiary C–H bond, though the singlet nitrene which was generated from methanesulfonyl azide reacted with the primary, secondary, and tertiary C–H bonds in the ratio of 1 : 4.2 : 9.6. The reactions with the tertiary C–H bonds of cis- and trans-1,4-dimethylcyclohexanes proceeded non-stereospecifically, in contrast to those of the nitrene with them. The addition of a radical inhibitor, hydroquinone, reduced the yield of II, while it increased the yield of III. The reaction with alcohols led to a quantitative yield of III, accompanied by the corresponding aldehydes. These results suggest that the reaction proceeds not by a nitrene mechanism, but by a metal-radical mechanism.
Carbon-13 NMR Spectra of 4-Chromanone, 4H-1-Benzothiopyran-4-one, 4H-1-Benzothiopyran-4-one 1,1-Dioxide, and Their Substituted Homologs
Authors: Senda Yasuhisa , Kasahara Akira , Izumi Taeko , Takeda Toru
Published: July 2006

The 13C NMR spectra of 4-chromanone, 4H-1-benzothiopyran-4-one, 4H-1-benzothiopyran-4-one 1,1-dioxide, and their methyl and phenyl substituted homologs were examined. The salient effect depending on the kinds of the hetero atoms or the group at the 1-position has been observed on the chemical shifts, especially for C-2, C-3, C-8, C-4a, and C-8a.
Micelle Formation of Purified Dinohylnaphthalenesulfonates in Benzene
Authors: Inoue Kiyoshi , Nose Yoshiharu , Watanabe Harumichi
Published: July 2006

The removal of trace amounts of unsulfonated dinonylnaphthalene contained in sulfonates by rubber membrane dialysis in pentane increased the apparent aggregation number of the micelles of dinonylnaphthalenesulfonate measured using vapor-pressure osmometry. The interaction between the cation and sulfonate ion was a factor affecting the aggregation, in addition to the steric factor of the hydrocarbon group and the solute-solvent interaction.
The ESR and ENDOR Spectra of the [2.2](2,7)Pyrenophane Anion Radical
Authors: Ishizu Kazuhiko , Sugimoto Yoshinori , Umemoto Teruo , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

The ESR and ENDOR spectra of the [2.2](2,7)-pyrenophane anion, which was prepared by reduction with alkali metal in ethereal solvents, were observed. From a comparison of the spin densities for the anion with those for the pyrene anion, the delocalization of the unpaired electron between the stacked aromatic rings was demonstrated.
The Preparation of Mixed Carbonate Complexes of Cobalt(III) with 2-Pyridinecarboxylic Acid
Authors: Ida Yayoi , Sakai Masaharu , Sakai Shigeru , Shibata Muraji
Published: July 2006

By the successive replacement of CO32− ions in the [Co(CO3)3]3− complex with 2-pyridinecarboxylic acid (Hpicol), the [Co (CO3)2(picol)]2− complex and two geometrical isomers of the [CoCO3(picol)2]− complex have been prepared. By the reaction of the cis-[Co(CO3)2(NH3)2]− complex and picol, three geometrical isomers of the [CoCO3(picol)(NH3)2] have been prepared.
The Radical Addition of Toluene to Fluorocyclobutenes
Authors: Kimoto Hiroshi , Muramatsu Hiroshige , Inukai Kan
Published: July 2006

Fluorine-containing cyclobutane derivatives, 1-benzyl-1,2,2,3,3,4,-hexafluorocyclobutane (1) and 1,5,6,6,7,7-hexafluorobenzo[2,3]bicyclo[3.2.0]hept-2-ene (2), were synthesized in one step by the radical reaction of toluene and hexafluorocyclobutene. On the other hand, a similar reaction of toluene and 1,2-dichlorotetrafluorocyclobutene gave no adduct, but a substituted product, 1-benzyl-2-chlorotetrafluorocyclobutene (4).
Studies of the Aqueous Solutions of Guanidinium Salts. VI. Complexes of Guanidinium Halides and Symmetrical Tetraalkylammonium Halides
Authors: Miyajima Koichiro , Yoshida Hiromitsu , Nakagaki Masayuki
Published: July 2006

Guanidinium halides (bromide and chloride) form crystalline complexes with symmetrical tetraalkylammonium bromides (tetraethyl-, tetrapropyl-, and tetrabutylammonium bromides and tetrabutylammonium chloride) in aqueous solutions at room temperature. These complexes were analyzed and found to be either binary complexes of two kinds of salts or ternary complexes with water as a third component. Each complex showed complicated peaks in the DSC measurements, which indicated the phase transition in the solid state. The solubility of each salt in ternary systems was measured, and phase diagrams were constructed for some of the ternary systems. A mutual salting- in effect was observed in all the ternary systems, and this effect was discussed in terms of complex formation and the structual change of water.
Magnetic Cross-over in Hexa-coordinate Iron(II) Complexes of Several Schiff Bases
Authors: Maeda Yonezo , Shite Shunji , Takashima Yoshimasa , Nishida Yuzo
Published: July 2006

Iron(II) complexes with the Schiff bases of 6-methyl-2-pyridinecarbaldehyde and 2-quinolinecarbaldehyde, and with α,α′-diimine were prepared. The M\ddotossbauer spectra and magnetic susceptibilities of the complexes, Fe(cbi)2(NCS)2·2/3CHCl3, Fe(tbi)2(NCS)2·CHCl3, Fe(mpmea)2(ClO4)2, and Fe(mepma)3(ClO4)2, were studied in the range of 80–298 K. It was found that these complexes show a 5T2-1A1 spin transition in the solid state.
Calculation of Directly-Bonded Nuclear Spin-Spin Coupling Constants with Localized Orbitals
Authors: Hirao Kimihiko , Kato Hiroshi
Published: July 2006

The directly-bonded nuclear spin-spin coupling constants were calculated by a perturbation method involving the summing over singly-excited states using localized orbitals. It is shown that a localized representation of orbitals in the perturbation expansion can be of considerable value both for interpretative purposes and for assessing the rate at which the pertubation expansion converges.
The Effects of Sodium Chloride on the Ultrasonic Properties of an Aqueous Solution of Isopropyl Alcohol
Authors: Nishikawa Sadakatsu , Mashima Mitsuo , Yasunaga Tatsuya
Published: July 2006

The ultrasonic absorptions in an aqueous solution of isopropyl alcohol with sodium chloride (NaCl) were measured in the frequency range from 2.5 to 220 MHz at 25 °C. The ultrasonic properties were remarkably affected by the addition of NaCl, and a new absorption was found around 7 MHz in addition to that observed in the solution without NaCl. The results were discussed in terms of the forming effects of NaCl on the water structure.
Formation of Indan and 2,3-Dihydrobenzofuran via Intramolecular Insertion of Phenylcarbene
Authors: Sekiguchi Akira , Ando Wataru
Published: July 2006

Pyrolysis of p-t-butyl- and p-trimethylsilylbenzaldehyde tosylhydrazone sodium salts gave indans via intramolecular C-H insertions of o-substituted phenylcarbenes through carbene-carbene rearrangements. Pyrolysis of o- and p-alkoxybenzaldehyde tosylhydrazone sodium salts afforded 2,3-dihydrobenzofurans.
The Formation and Properties of Solid Solutions in the PbTiO3-Pb(Ni1⁄2W1⁄2)O3 System
Authors: Torii Yasuyoshi
Published: July 2006

By usual and high-pressure techniques, a series of PbTiO3–Pb(Ni1⁄2W1⁄2)O3 solid solution was formed with a perovskite structure. With an increase in the Pb(Ni1⁄2W1⁄2)O3 content, the Curie point shifted to lower temperatures and the degree of tetragonality decreased. The thermal-expansions were also measured, showing anomalies at the Curie point.
Photochemistry in the Adsorbed Layer. VIII. Lifetimes of Excited Alkyl Ketones and Alkyl Radicals Adsorbed on Porous Vycor Glass
Authors: Anpo Masakazu , Wada Toshiaki , Kubokawa Yutaka
Published: July 2006

The photolyses as well as the absorption spectra of adsorbed 3-methyl-2-butanone and 3-methyl-2-pentanone have been investigated in the presence and absence of nitrogen monoxide. The Stern-Volmer relationship was applied to the decrease in the rate of photolysis caused by addition of nitrogen monoxide. From the results together with those for acetone, 2-butanone, and 2-pentanone, it has been concluded that in the adsorbed layer the more blue shifted, i.e., the more strongly hydrogen bonded to the surface OH groups a ketone molecule, the shorter the lifetime of its excited state. It has been found that the lifetime of the alkyl radical on the surface increases with the decrease in its ionization potential, leading to the decrease in the strength of its interaction with the surface. Special features of the photolysis in the adsorbed layer have been described for 3-methyl-2-butanone photolysis.
A Convenient Two-Step Synthesis of Bis(polyalkylphenyl) Disulfides from Polyalkylbenzenes
Authors: Suzuki Hitomi , Shinoda Misao
Published: July 2006

Heating of polyalkyliodobenzenes with copper(I) thiocyanate in phosphoric tris-dimethylamide at 180–190 °C for a short period of time gives the corresponding bis(polyalkylphenyl) disulfides in high yields.
Preparation and Stereochemistry of Cobalt(III) Complexes Containing N-Methylbis(2-aminoethyl)amine
Authors: Kojima Masaaki , Iwagaki Masaru , Yoshikawa Yuzo , Fujita Junnosuke
Published: July 2006

Seven new cobalt(III) complexes containing N-methylbis(2-aminoethyl)amine (4-methyldiethylenetriamine, abbreviated as dema) were prepared and their structures were determined by electronic, circular dichroism, and PMR spectroscopy. For the mixed [Co(dien) (dema)]3+ complex (dien=diethylenetriamine), three geometric isomers, s-fac, u-fac, and mer were isolated. The [Co(dema)2]3+ complex formed only s-fac isomer. A conformational analysis was carried out to compare the stability of these geometric isomers.
Various Acceleration Conditions of Pummerer Reaction Observed in the Total Synthesis of Illudins
Authors: Matsumoto Takeshi , Shirahama Haruhisa , Sakan Fujio , Takigawa Kazuko
Published: July 2006

Pummerer reaction of highly functionalized sulfoxides were examined under various modified conditions. The results indicated that added base and/or neighboring acetoxyl group accelerated the reaction.
Sydnones. Synthesis and Photochromic Behavior of 3-(3-Pyridyl)sydnone Derivatives and a 4-Alkenyl-3-phenylsydnone
Authors: Inoue Shinichi , Asai Nobuyoshi , Yasuda Gorou , Hori Takuya
Published: July 2006

Six new-sydnones [3-(3-pyridyl)-4-(p-chlorophenyl)sydnone (1), 3-(3-pyridyl)-4-(p-tolyl)sydnone (2), 3-(3-pyridyl)-4-(p-nitrophenyl)sydnone (3), 3-(3-pyridyl)-4-(p-aminophenyl)sydnone (4), 3-(3-pyridyl)-4-(p-acetamidophenyl)sydnone (5), and 3-phenyl-4-(α-phenylstyryl)sydnone (6)] were synthesized and examined for photochromic behavior. Sydnone 2 exhibited photochromism in the solid state upon UV irradiation (230–580 nm).
Reactions of Perfluoro-2,5-dimethyl-3,4-hexanedione with Amines
Authors: Shin-ya Seiji , Ishikawa Nobuo
Published: July 2006

Perfluoro-2,5-dimethyl-3,4-hexanedione and aromatic or aliphatic amines gave the respective 1:1 adducts in good yields. With excess amounts of aliphatic amines or basic aromatic amines such as p-anisidine, the perfluorodiketone gave oxamides. With o-phenylenediamine, it gave 2,3-dihydroxyquinoxaline.
Phenanthro[4,5-bcd]furan Derivatives. IV. A Synthesis of Phenanthro[4,5-bcd]furan
Authors: Horaguchi Takaaki
Published: July 2006

Phenanthro[4,5-bcd]furan was synthesized from 1,2,3,8,9,9a-hexahydrophenanthro[4,5-bcd]furan-3-ol by dehydrogenation with palladium-charcoal. Some chemical reactivities and spectral properties of phenan thro [4,5-bcd]furan were investigated and compared with those of phenantherene and dibenzofuran. The results suggest that phenanthro[4,5-bcd]furan has the chemical properties of both phenanthrene and dibenzofuran, and does not have a large strain in the fused-ring system. Also, the reactivities of 1,2,3,8,9,9a-hexahydrophenanthro[4,5-bcd]furan-3-one were explored.
Proton Spin Lattice Relaxation in Blends of Natural Rubber and Polyterpene
Authors: Ito Masayoshi , Tanaka Koji
Published: July 2006

NMR measurements were carried out on blends of natural rubber (NR) and polyterpene (PT). The blends of NR and PT are perfectly mixed. The motion of NR chains play a dominant role in the glass transition of the blends. The mobility of NR segments in the blends are constrained by the presence of PT.
The Preparation and Stereochemistry of Optically Active Cobalt(III) Complexes with 3,3′-Dimethyl-2,2′-bipyridine and Bis(diamines) or Tetramines
Authors: Suzuki Toshishige M , Kimura Tetsuo
Published: July 2006

Bis(en), trien, tren and bis(R,R-chxn) cobalt(III) complexes of 3,3′-dimethyl-2,2′-bipyridine (dmbpy) have been prepared and resolved. The dissymmetric conformation of dmbpy arising from the non-coplanarity of the two pyridine rings is maintained in the inert complexes. 3,3′-Dimethyl-2,2′-bipyridine coordinates to the cobalt(III) ion with a stereospecific conformation depending on the configuration. The absorption and circular dichroism (CD) spectra of the dmbpy complexes were compared with those of the corresponding 2,2′-bipyridine (bpy) complexes.
Spectral Studies on the Interaction between Oxovanadium(IV) β-Diketonates and Organic Solvents
Authors: Adachi Natumi , Fukuda Yutaka , Sone Kozo
Published: July 2006

The effect of temperature on the visible absorption spectra of oxovanadium(IV) β-diketonates [VO (β-dik)2] (β-dik=aca, bza, tfa, and dpm*) were studied in organic solvents. The results together with the spectral and thermogravimetric data of the pyridine and dioxane adducts of these chelates lead to the conclusion that the ease of taking up a solvent molecule to form a six-coordinate solvated chelate in solution increases in the order: VO(tfa)2>VO(bza)2≈VO(aca)2>VO(dpm)2. Various proofs for the existence of a polymeric structure of VO(tfa)2, which was formerly indicated on the basis of its IR spectrum, were found.
12,13-Epoxy-C-nor-D-homosteroids. III. The Synthesis and Stereochemistry of 17-Oxygenated 12,13-Epoxyetiojervanes
Authors: Murai Akio , Iwasa Noriaki , Takeda Masami , Sasamori Hiroshi , Masamune Tadashi
Published: July 2006

The synthesis of several 17-oxygenated 12,13-epoxyetiojervanes is described. Jervine (1) was degraded by a known procedure into trienone (10), which on hydride reduction afforded 11α- and 11β- alcohols (11 and 12). The respective alcohols were submitted to the Lemieux-Johnson oxidation to give Δ12-17-oxo-11-alcohols (13 and 14), which were reduced under the Birch conditions to yield Δ12-17-ketone (15). Epoxidation of these alcohols and ketone produced the aimed epoxides (18–24). The structure and configuration of these epoxides and the synthetic intermediates were determined on the basis of the chemical and spectral evidence.
Fluorination with Substituted (Difluoroiodo)arenes
Authors: Gregorcic Ana , Zupan Marko
Published: July 2006

The reaction of substituted (difluoroiodo)arenes with 1-phenyl-1-(m-chlorophenyl)ethylene results in 1,1-difluoro-1-(m-chlorophenyl)2-phenylethane, with 1-phenyl-1-(p-methoxyphenyl)ethylene in 1,1-difluoro-1-phenyl-2-(p-methoxyphenyl) ethane, and with 1-phenylcyclopentene and 1-phenylcyclohexene in rearranged gem-difluoro compounds. The reaction with norbornene results in three products: fluoronortricyclane (9–12%), 2-exo-7-syn-difluoronorbornane (75–86%), and 2-exo-7-anti-difluoronorbornane (5–15%) depending upon the substituent on the phenyl ring in (difluoroiodo)arenes.
The Reactions of β-Amino Enones with Hydroxylamine
Authors: Kashima Choji , Yamamoto Yasuhiro , Omote Yoshimori , Tsuda Yoshihiko
Published: July 2006

The reactions of N-substituted β-amino enones with hydroxylamine give two isoxazole isomers. The ratio of these isomers changes with the electron-withdrawing effect of the N-substituents.
The Palladium-catalyzed Phenylation of Enol Esters with Iodobenzene
Authors: Kasahara Akira , Izumi Taeko , Fukuda Naoki
Published: July 2006

The palladium-catalyzed phenylation of olefins with iodobenzene has been extended to enol esters. In the presence of triethylamine and a catalytic amount of palladium acetate, vinyl acetate is phenylated with iodobenzene to produce, mainly, stilbene, accopanied by small amounts of (E)- and (Z)-styryl acetates.
Magnetic Properties of Oxovanadium(IV) Complexes with Bidentate ON Donor Schiff Bases
Authors: Syamal A
Published: July 2006

The magnetic properties of oxovanadium(IV) complexes of Schiff bases(I) are reported. Contrary to an earlier report that these complexes are involved in magnetic exchange, the complexes are found to be magnetically dilute. The complexes display μeff in the range 1.68–1.71 B. M. at 78–297 K with θ=2–4 K, and exhibit 8 line ESR spectra.
Statistical Thermodynamic Theory of Liquid Water
Authors: Arakawa Kiyoshi , Tokiwano Kazuo , Kojima Kazumitsu
Published: July 2006

A new statistical thermodynamic theory is presented for a model of liquid water, which consists of two components, i.e., tetrahedrally-coordinated pentamers and non-hydrogen-bonded monomers. In the model the two components are assumed to be immersed in a uniform background potential which results from electrostatic, induction, and dispersion forces between water molecules. A partition function is given without assuming any specified lattice. A translational partition function is written into a simple and explicit expression which is derived from the Lebowitz solution of the Percus-Yevick equation for hard sphere mixtures. The mole fraction of each component and the density are determined by solving two equations, i.e., the condition of free energy minimization and the equation of state derived from the partition function, simultaneously. Various thermodynamic quantities are calculated and the values determined are compared with those observed. Some discussions are carried out, together with the criticism of the earlier theories.
The Liquid-phase Oxidation of Acetaldehyde with Metal Polyphthalocyanines. Solvent Effect
Authors: Ohkatsu Yasukazu , Hara Takao , Osa Tetsuo
Published: July 2006

Acetaldehyde was oxidized using metal polyphthalocyanines as catalysts. Metal polyphthalocyanines, especially Fe,Cu–polyphthalocyanine, were found to be useful oxidation catalysts for the selective formation of peracetic acid from acetaldehyde. The rate of oxidation was much affected by the nature of the solvents. The solvent is considered to take part in the initiation oxidation reaction in two ways: one is based on the prevention of the oxygen molecule from coordination with a metal polyphthalocyanine and subsequent activation, and the other is due to the solvation with the activated oxygen molecules on the catalyst. Preferable solvents were ethyl acetate, bromobenzene, benzene, and acetone.
The Reaction of 4-Thiazoline-2-thione with Methyl Iodide. Solvent Effects and Pressure Effects
Authors: Kondo Yasuhiko , Shinzawa Masayuki , Tokura Niichiro
Published: July 2006

Rate constants for the reaction of 3-isopropyl-4-methyl-4-thiazoline-2-thione with methyl iodide have been determined in several solvents at 1 atm. In acetonitrile and propylene carbonate, the reaction was studied at pressures up to 1500 atm by a conductivity method. A comparison of the activation volume and overall volume change of reaction, obtained from density measurements, suggests that the charge development at the transition state is only fractional. The results of CNDO/2 calculations support the argument.
Photoelectrochemical Behavior of n-Type TiO2 and Other Semiconductor Electrodes in Acetonitrile Solutions Containing Various Aromatic Amines
Authors: Nakatani Kenji , Tsubomura Hiroshi
Published: July 2006

The electrode behavior of n-type TiO2 in acetonitrile solutions containing one of a variety of aromatic amines under illumination has been investigated. The onset potential of the anodic photocurrent leading to the oxidation of the amines changed from the most negative −0.51 V vs. SCE for N,N,N′,N′-tetramethyl-p-phenylenediamine to the least negative −0.27 V for aniline. These values parallel the change of the flat band potential by the amine and become more negative as the ionization potential of the amine decreases. The influence of the amine on the flat band potentials of ZnO, CdS, and GaP was also studied and found to be much less than in the case of TiO2. From these results, the reason for the change of the flat band potential in the case of TiO2 is attributed to a specific charge transfer interaction between the semiconductor and the amine.
The Distribution of Higher Alcohols in Aqueous Micellar Solutions
Authors: Hayase Kohji , Hayano Shigeo
Published: July 2006

The distribution coefficients, K, for 1-butanol, 1-pentanol, 1-hexanol, and 1-heptanol between the sodium dodecyl sulfate (SDS) micellar and aqueous phases were measured directly, with the gas chromatographic technique was used to measure the vapor pressure of the alcohols. The standard free energy change of penetration, ΔGp°, of the alcohol from the aqueous to the micellar phase was obtained using the equation: ΔGp°=−RTlnK. There is a linear relation between ΔGp° and the carbon number of the alcohol.
Intersystem Crossing Processes of Acridine
Authors: Kikuchi Koichi , Uji-ie Koji , Miyashita Yoshikatsu , Kokubun Hiroshi
Published: July 2006

The T1(π, π*)→T3(π, π*) absorption of acridine has first been observed at about 985 nm in ethanol. Temperature dependences of the fluorescence lifetime and the triplet yield of acridine were investigated in poly(vinyl alcohol) film, and it was found that the intersystem crossing from the first excited singlet state S1(π, π*) to T1(π, π*) occurs through both temperature dependent and independent processes. The activation energy of the temperature dependent process corresponds substantially to the energy difference between T3(π, π*) and S1(π, π*). The intersystem crossing from S1(π, π*) to T2(n, π*) followed by the internal conversion to T1(π, π*) was assigned to the temperature independent process.
Thermal Analysis and NMR Observation of 66-Nylon
Authors: Ito Masayoshi , Kanamoto Tetsuo , Tanaka Koji
Published: July 2006

The effects of morphology on γ-relaxation in 66-Nylon is investigated. The morphology of the samples was characterized mainly by thermal analysis. Information about the molecular motion of 66-Nylon is obtained from the temperature dependence of the spin-lattice relaxation times (T1). In order to compare the relaxation behavior of 66-Nylon with that of other semicrystalline polymers, the T1 of polyoxymethylene (POM) was also measured as a function of temperature. It was found that in 66-Nylon, both solution-grown crystals and bulk samples are composed of folded chain lamellae with fairly large amounts of less perfect crystalline regions. Both the magnitude and the temperature of the T1 minimum at about 30 °C (γ-region) for 66-Nylon are not sensitive to the sample history, in contrast to those for POM. In addition, the T1-temperature curve in the γ-region for 66-Nylon is much broader than that for POM. These NMR results for 66-Nylon are interpreted in terms of a rather wide variety of structural heterogeneities from the usual amorphous regions to fairly restricted regions, such as the less-perfect crystalline regions at the lamellar surface.
The Molecular-Symmetry Reduction in Open-Shell Conjugated Hydrocarbons
Authors: Toyota Azumao , Nakajima Takeshi
Published: July 2006

On the basis of the second-order Jahn-Teller theorem, we propose a criterion for predicting the stable groundstate geometrical structures of open-shell conjugated hydrocarbons. It is found that in contrast with the cases of the parent closed-shell hydrocarbons no molecular symmetry reduction occurs in the ion radicals of the CmHm–2 catacondensed nonalternant hydrocarbons, such as pentalene and heptalene. On the other hand, it is revealed that the ion radicals of fulvalene systems suffer the molecular symmetry reduction from D2h to C2v. In addition, the electronic spectra were calculated using the stable geometrical structures obtained by use of the semiempirical open-shell SCF MO method.
Reaction of Carbon Dioxide with Tetraphenylporphinatoaluminium Ethyl in Visible Light
Authors: Inoue Shohei , Takeda Norikazu
Published: July 2006

Tetraphenylporphinatoaluminium ethyl reacts with carbon dioxide in the presence of 1-methylimidazole to produce tetraphenylporphinatoaluminium propionate in the presence of visible light but not in the dark.
A Molecular Orbital Calculation of Chemically Interacting Systems. Interaction between Two Radicals
Authors: Minato Tsutomu , Yamabe Shinichi , Fujimoto Hiroshi , Fukui Kenichi
Published: July 2006

The reaction path of radical-radical recombination and disproportionation has been studied by means of a perturbational method with a clear orbital interaction concept, and the mechanism of these reactions has been elucidated theoretically. It has been confirmed that these termination reactions do not have a common transition state. The recombination is found to take the path which gives the maximum interaction between the singly occupied molecular orbitals (SOMO’s) of two radical species, whereas the disproportionation is shown to take the route which gives the significant charge transfer interaction from the particular doubly occupied (DO) MO of one radical to the SOMO of the other radical. The DOMO localized at the C–H bond donates electrons to the SOMO to cause the hydrogen abstraction. In the process of disproportionation, one radical which abstracts a hydrogen atom acts as an electron-acceptor and the other radical with the hydrogen atom to be abstracted as an electron-donor. The difference between the mechanism of the recombination and that of the disproportionation is clarified in terms of the mode of the orbital interaction.
Structural Studies of the Interaction between Indole Derivatives and Biologically Important Aromatic Compounds. II. The Crystal and Molecular Structure of the Tryptamine–Phenylacetic Acid (1:1) Complex
Authors: Inoue Masatoshi , Sakaki Toshimasa , Fujiwara Takaji , Tomita Ken-ichi
Published: July 2006

The title complex crystallizes in the monoclinic space group of P21/c. The unit-cell dimensions are a=6.673(4), b=19.017(8), c=13.394(7) Å, and β=110.54(2)°. The crystal structure was solved by a direct method. By block-diagonal least-squares refinements, the R-value converged to 0.062. In this complex, a salt bridge is found between the anionic carboxyl group of phenylacetic acid (PAA) and the cationic amino group of tryptamine (TPA). All the hydrogen atoms attached to the nitrogen atoms participate in the hydrogen bonding. The two complex molecules are hydrogen-bonded around a center of symmetry to form one unit, which is held together by van der Waals contacts in the b- and c-directions. Each unit is also stabilized by forming a hydrogen bond with the unit of the neighboring cell translated in the a-direction.
Oxidation of 2-Aryl-4H-1-benzopyrans with Potassium Permanganate
Authors: Kurosawa Kazu , Ashihara Yoshihiro
Published: July 2006

The oxidation of twelve 2-aryl-4H-1-benzopyrans with potassium permanganate in acetone gave the corresponding flavones in excellent yields.
Vibrational Spectra of Dimethylaminosulfonyl Chloride and Its C-Deuterated Derivative
Authors: Tanaka Yukiko , Tanaka Yoshimasa , Saito Yutaka , Machida Katsunosuke
Published: July 2006

The infrared and Raman spectra of dimethylaminosulfonyl chloride and its C-deuterated derivative have been recorded in the liquid state. The fundamental frequencies have been assigned by referring to the band intensities, Raman depolarization ratios and isotopic frequency shifts. A normal coordinate analysis based on a planar Cs molecular model has been carried out by using a simple Urey-Bradley force field for stretching and bending coordinates and a valence force field for torsional coordinates. The calculated frequencies based on a refined set of force constants agree well with the observed ones.
The Crystal Structure of Monoaquabis(1,10-phenanthroline)copper(II) Tetrafluoroborate [Cu(H2O)(phen)2](BF4)2
Authors: Nakai Hisayoshi , Noda Yukinao
Published: July 2006

The crystal of the title compound is monoclinic, with a=19.099(6), b=8.100(3), c=16.177(5) Å, β=100.54(5)°, the space group of C2/c, and Z=4. The structure was determined from the counter data and was refined to R=0.083 for 1736 non-zero reflections. The coordination geometry of the copper atom is best described as a distorted trigonal bipyramid, in which the equatorial plane is composed of Cu, two N, and water O atoms, and the axial positions are occupied by two N atoms. The complex has a crystallographically imposed twofold axis which passes through the copper and the water oxygen atoms at the equatorial plane. The two phenanthroline ligands are related with each other by this axis.
Heterofulvalenes. I. 5-Aza- and 6-Aza-1,4-dithiafulvalenes
Authors: Nakayama Jyuzo , Watabe Yukie , Hoshino Masamatsu
Published: July 2006

5-Aza, 2,3-benzo-5-aza-, 6-aza-, and 2,3-benzo-6-aza-1,4-dithiafulvalenes were synthesized and their spectroscopic properties are described. For example, the reaction of 2-methylthio-1,3-dithiolylium iodide with pyrrole gave 2-(2-pyrrolyl)-1,3-dithiolylium iodide in a 92% yield, which was treated with DBU, giving rise to 5-aza-1,4-dithiafulvalene as thermally-stable orange crystals in an 82% yield. Several reactions found during the course of these synthetic studies are also reported.