In the reactions of reagents having C-Mg, N-Mg and O-Mg bonds with substrates having functional groups (NO₂, CO, CN), distribution of the normal (addition and condensation) and abnormal (radical) products is correlated with the values of difference between oxidation and reduction potentials of the reactants (ΔE=E_ox−E_red) which estimate the relative efficiency of single electron transfer (SET). The study is called ΔE-approach.
Mild reactivity of the N-Mg reagent derived from anilines is profitable for disclosure of factors governing all of the reactions of the reagent to allow all of those to be classified and characterized. It was found that the use of strongly coordinating ligands as additives led to disclosure of the implicit SET in large ΔE reaction, which was also useful for improvement of the yield of the normal products.
Two essential features (I and II) of the reactions are derived: I) Participation of SET and σ-complexation (e.g.>C=O…Mg<) is necessary for the formation of normal products from the reaction components; and II) an excess amount of reagent assists later step of the reaction (i.e., radical transfer leading to product formation). Feature II) implies that the later step proceeds in an assembly composed of the generated pair of radical species and excess reagent molecules (i.e., in a closed environment), this feature being considered to validate the ΔE-approach stating that the most basic one of initial conditions (i.e., potential difference) relates to the final distribution of products even in the multistep reactions. Basic guide lines for exact use of the magnesium reagents are thus given.

View full abstract

Photochemical reactions of N-(phenylalkyl, 2-pyridyl, or 2-pyridylmethyl)-o-sulfobenzoic imides 2-5 were examined in ethanol and benzene solutions. Irradiation in ethanol afforded benzamides 7, 9, 11, 14, and in benzene solution 2-phenylbenzamides 8, 10, 12, 15 were obtained. Irradiation of N-(2-pyridyl)-o-sulfobenzoic imide(5) generated benzo[c][1, 8]naphthyridin-6(5H)-one(13) as an additional product. This photocyclization was clarified to proceed via the S₁ state by the triplet quenching experiment. Those photochemical reactions were proposed to occur via a biradical formed by extrusion of SO₂. On ESR measurement of N-propyl-o-sulfobenzoic imide(1) irradiated in the methanol matrix at 15 K, the signals of a monoradical of g=2.0048 and a methyl radical were observed, but the existence of the biradical was not confirmed.

View full abstract

In order to study the characteristics of anion exchange resin that may effectively bound the dietary phosphate in digestive system, in vitro and in vivo studies in phosphate binding were carried out by comparing anion exchange resins, PAA-B, WA10, and Dowex 1×8, with calcium carbonate. In vitro phosphate binding experiments, the anion exchange resins used bound lesser phosphate than calcium carbonate at pH7. The binding equilibrium of resins, however, was reached within 1 hour and was more rapidly than that of calcium carbonate without pretreatment of acid solution. In vivo phosphate binding experiments, the fecal phosphorus excretions of rats with PAA-B, WA10, Dowex 1×8, or calcium carbonate were increased by 77.4, 38.4, 8.4, or 57.7%, respectively. While the uric phosphorus excretions were decreased by 73.9, 42.7, 20.5, or 66.9%, respectively. Famotidine, histamine H₂ receptor antagonist, significantly reduced phosphate binding of calcium carbonate (P<0.01) while it had no influence on anion exchange resins. These results suggest that anion exchange resin, especially in which the primary and secondary amino type anion exchange groups are maximally introduced, has a bright prospect of an effective drug for treating hyperphosphatemia in patients with chronic renal disease of end stage and with hemodialysis.

View full abstract

We synthesized novel formaldehyde acetals bearing long chain alkyl groups, which could be potential chain transfer agent for the polymerization of trioxane. We formerly reported the synthesis of a new poly(oxymethylene) with a long chain alkyl group using 1-octadecanol as a chain transfer agent. However, using 1-octadecanol, one of the end-groups of the obtained polymer is a thermally stable octadecyloxy group, and the other is thermally unstable hydroxy group, respectively. The polymer with thermally stable both end groups is desired. For this purpose, we synthesized formaldehyde methyl octadecyl acetal, formaldehyde bisoctadecyl acetal, starting from 1-octadecanol and formaldehyde dimethyl acetal as raw material using a cationic ion exchange resin as catalyst by acetal exchange reaction. Synthesized materials are confirmed with ¹H-NMR, mass spectra and elemental analysis. We also synthesized formaldehyde acetal with a longer chain alkyl group starting from an alcohol of carbon number of 38.

View full abstract

With the aim to develop a new type of UV-protective cosmetic material being less irritant to skin, the silica gels having chemically bonded ultraviolet absorbent were prepared by the modification of the surface of the silica gels with cinnamamido groups. The silica gel sample were evaluated by their visible and UV transmittance spectra and the samples made from non-porous fine particle of silica gels were found to be transparent to visible light and screen ultraviolet rays. The appearance of the chemically modified silica gels was clear and natural when applied to human skin.

View full abstract

To use brewer’s refuse as adsorbent adsorption of metal ions and acid dyes on them and their reaction products with 1, 3, 5-triacryloylhexahydro-1, 3, 5- triazine(TAF) were examined. The refuse samples used in the present study are protein rich fraction(Pr) and cellulosics rich fraction (Hr) obtained by sifting brewer’s refuse. Adsorptive experiments were conducted by a batchwise method at 303K.
Pr adsorbed more metal ions such as Cr⁶⁺, Ni²⁺, Co²⁺, especially Fe³⁺, Hg²⁺ and Cu²⁺ than Hr. But both refuses hardly adsorbed Ca²⁺. Also Pr adsorbed more acid dyes, especially more hydrophorbic C.I.Acid Red88 than C.I.Acid Orange7- than Hr at pH5. By crosslinking Pr and Hr using TAF adsorption of acid dyes increased markedly, but adsorption of metal ions decreased. Therefore Pr can be used as adsorbent for acid dyes and metal ions as it is. Moreover the crosslinked products are excellent adsorbents for acid dyes.

View full abstract

Sulfur isotope ratio(δ³⁴S) was measured for coals and oils used in northern China, eastern Russia and Japan. The δ³⁴S values of northern Chinese coals and Russian coals are 7.7±11.4‰(about 5‰ in median) and 4.5±4.8‰ in average, which are higher than those reported for coals in southern China. This suggests the difference of coal forming processes between northern China, eastern Russia and southern China. Oils(main fuel in Japan) show low δ³⁴S values that are very different from those of Chinese and Russian coals. These differences in sulfur isotope ratios are reflected to the seasonal variation of sulfur isotope ratios of rain and aerosol in the Japan Sea side of Japan.

View full abstract

The material balance of carbonization products (wood-gas, wood-vinegar, wood-tar and charcoal) prepared from the sapwood and the heartwood of Sugi (Cryptomerica japonica D. Don) at various temperatures was determined. The evolution of both carbon monoxide and carbon dioxide mainly occurred at the carbonization temperature below 600°C and that of hydrogen and methane at 600-800°C. Total yield of the wood-vinegar and the wood-tar was almost constant at 500-800°C. On the other hand, the yield of the charcoal decreased because of the evolution of the wood gas with an increase in carbonization temperature.
The wood-vinegars prepared at the temperature over 400°C were found to consist of carboxylic acids such as acetic acid and propionic acid, methanol, acetone, furans, alkylphenols, guaiacols, cyclotene and maltol by capillary gas chromatography. Since the constituent varieties and contents of the wood-vinegars prepared at both 400°C and 800°C were very similar each other, the wood-vinegar of Sugi wood chiefly produced below 400°C.
FT-IR spectra of the charcoals showed the generation of carbonyl and olefin groups at 300-400°C and then the formation of aromatic rings along with the disappearance of carbonyl groups over 600°C. The production of radical species in the charcoals carbonized at 300-600°C was observed by ESR, on the contrary, the charcoals carbonized over 700°C were inactive. The specific surface area and the pore volume of the charcoal of Sugi sapwood increased with an increase in carbonization temperature. The pH of charcoal-dispersed aqueous solution increased with an increase in carbonization temperature. The high adsorptive activity of the charcoal carbonized at 400°C for ammonia gas and that at 800°C for hydrogen sulfide gas seemed to be dependent on acidic and basic properties of the charcoals, respectively.

View full abstract

Large decrease in discharge capacity of hydrogen storage alloy negative electrodes was observed by assembling with nickel hydroxide positive electrodes containing cadmium. From the relationship between discharge rate and discharge capacity of the negative electrode, and analysis by potential step method, the mechanism of this phenomenon was presumed to be as follows:
1) Cadmium in the positive electrodes dissolves into an electrolyte, and then transfers on the surface of the hydrogen storage alloy particles.
2) Transferred cadmium impedes hydrogen diffusion between the inside of the alloy and the surface reaction sites where charge/discharge reaction takes place. Therefore, remarkable decrease in the discharge capacity of the negative electrode is observed.

View full abstract

Coumarin dimers generally show high reactivity in ring-opening polyaddition reaction with diamine to give a high-molecular-weight polyamide. However, the reaction of anti head-to-tail 4-styrylcoumarin dimer with hexamethylenediamine gave no polyamide at all. It was found that after the first ring-opening reaction by amine, styryl group on cyclobutane ring unexpectedly decreased electrophilicity of carbonyl group and disturbed the second ring opening reaction. After the first ring-opening, IR peaks of carbonyl group in the lactone ring and olefin group in the styryl group, remarkably shifted to the lower wavenumber. Based on the observed IR spectral shifts, unusual stabilization of the second lactone ring was shown.

View full abstract

The reaction of trimethylenemethane with various alkyl-substituted p-benzoquinones was investigated. The reaction of 2, 5-di-tert-butyl-p-benzoquinone with 2-(trimethylsilylmethyl)allyl acetate(1) was conducted with palladium(0) as a catalyst to afford 1:1-C=C-cycloadduct 2 in good yield. Similarly, 1:1-C=C-cycloadducts 3, 4, 5 and 6 were obtained with 2, 6-di-tert-butyl-p-benzoquinone, 2, 3, 5, 6-tetramethyl-p-benzoquinone, 2, 3, 5-trimethyl-p-benzoquinone and 2-methyl-1, 4-naphthoquinone, respectively. On the other hand, the reaction with methyl-p-benzoquinone afforded the complicated mixture. As is the case with Diels-Alder reactions, the cycloaddition of trimethylenemethane with p-benzoquiones occurred towards C-C double bond. So, the reaction of trimethylenemethane with substituted p-benzoquinones is effective in the synthesis of methylenecyclopentane-fused cyclohexenediones having various substituents.

View full abstract