Kiichiro Sugino

Mechanism of Hydrocarbon Formation in the Electrolytic Reduction of Acetone in Aqueous Sulfuric Acid

A tentative mechanism or hydrocarbon formation is proposed which, by combining the usual mechanism of pinacol and isopropanol formation, will contribute to one clarification of the over‐all electrode process of acetone reduction (see PDF for formula). The main point lies in the fact that the radical is further reduced with dehydration of propane through the isopropyl radical which is combined with the cathode metal. In certain cases (mercury and lead, etc.) the reaction products with metal (organometallic compound) can be isolated in a relatively stable form. Generally speaking, cathode material having a negative standard electrode potential tends to follow this hydrocarbon formation process.

Anodic Processes of Acetate Ion in Methanol and in Glacial Acetic Acid at Various Anode Materials

The anodes used in this study were platinum, gold, palladium, lead dioxide, and graphite. The normal Kolbe process, the formation of ethane (and methane) and carbon dioxide, can be realized at a potential higher than 2.0v (vs. SCE) in both methanol and glacial acetic acid. In methanol, only platinum and gold seem to be suitable for realizing the process. In glacial acetic acid, however, all of the anodes except graphite can be used successfully for the same process. Another process, the formation of methyl acetate, occurs in both solvents at graphite in the potential range 1.4–2.0v. A side reaction observed in methanol at palladium, graphite, and lead dioxide was the formation of formaldehyde (and methyl formate in case of lead dioxide) which occurs at potentials as low as 1.2v.

Cathodic crossed hydrocoupling of acetone with acrylonitrile and maleic acid

Abstract The cathodic crossed hydrocoupling of acetone with acrylonitrile, which occurs at about −1·20 V(sce) in aqueous sulphuric acid, has been investigated. At mercury the yield ana the current efficiency for the hydrocoupling product were both over 70 per cent based on acrylonitrile. However, at lead and at cadmium, both decreased, with increasing hydrocarbon formation. It was also observed that benzophenone could hardly be hydrocoup led with acrylonitrile under the same conditions. The results support a tentative mechanism of this process, in which the reaction of a hydroacetone anion with an acrylonitrile molecule was proposed. This reaction was found to be applicable to methylethylketone and diethylketone with 60 and 30 per cent current efficiency respectively. In aqueous quaternary ammonium salt solution, the same reaction may be obtained at −1·90 V though the yield of the product is not as good. This may be the reaction of a hydroacrylonitrile anion with an acetone molecule. The formation at the cathode of terebic acid from a mixture of acetone and maleic acid is also reported.

Electrolytic Reduction of 2‐Amino‐4‐chloropyrimidine, 2‐Amino‐4‐choro‐6‐methylpyrimidine, and 2‐Aminopyrimidine

2‐Amino‐4‐chloropyrimidine and its 6‐methyl derivative give two polarographic waves in the pH region of 7.4–8.9; 2‐aminopyrimidine and 2‐amino‐6‐methylpyrimidine yield but a single wave in this region. Macroscale electrolysis at lead or mercury cathodes in ammoniacal medium shows that the first wave of the chlorocompounds arises from reductive dehalogenation. The second wave of the chlorocompounds coincides with the single wave of their parent compounds, the 2‐aminopyrimidines, and is ascribed to reduction of the pyrimidine nucleus in both cases. The macroreduction of 2‐aminopyrimidine takes place easily at lead or mercury cathodes in ammoniacal medium to yield 2 ‐aminodihydropyrimidine. The mechanism of reduction is tentatively identified as pure electrolytic reduction.The reduction of 2‐amino‐4‐chloropyrimidine to 2‐aminopyrimidine at cathodes of lead and mercury in aqueous methanolic ammonium sulfate was found to be impractical on a preparative scale. On the other hand at spongy cadmium the reduction takes place in 90% yield. At spongy zinc the yield is poorer due to further reduction of the pyrimidine nucleus. However, for the reduction of 2‐amino‐4‐chloro‐6‐methylpyrimidine zinc is superior to cadmium as a cathode.

Cathodic crossed hydrocoupling XIII. Synthetic aspect of the cathodic crossed hydrocoupling reaction of aliphatic carbonyl compounds with electrophiles in aqueous sulfuric acid

Abstract For the purpose of organic electrosynthesis, the cathodic crossed hydrocoupling of aliphatic carbonyl compounds with some electrophiles was investigated. When mixtures of carbonyl compounds (such as ketone and aldehyde) and electrophiles (such as activated olefin, pyridine, and cyanamino compound) were electrolysed with various kinds of cathodes in aqueous sulfuric acid, these compounds were coupled reductively to give many useful products in the field of synthetic organic chemistry. In most of the couples of carbonyl compounds and electrophiles, the reduction potentials of the formers were more positive than those of the latters under the electrolysis condition. The yield, current efficiency, and selectivity of products depended on electrolytic conditions, especially cathode material.

Segregate Carbon in Calcium Cyanamide

石灰窒素誘導体工業の進展に伴ない, 窒素分浸出残留物の利用は一つの重要な工業的課題となった。そこでまずその中に含まれている遊離炭素の性状を明らかにして,その有効適切な利用に資そうとして研究を行った。亀山博士はすでに大正10年にこの石灰窒素中の炭素について報告し,この炭素が黒鉛質であることを明かにした。その後これについての研究は余り見あたらないようであり, 他方, 近年黒鉛性状の研究の進展および測定法の進歩など著しいので, この問題をとり上げて再検討を行ったものである。残留物を塩酸および15%程度のフッ酸液で処理して得られた石灰窒素中の炭素は灰分が1.1～1.2wt%である。不純物はβ-SiCのほかに発光分光分析によりカルシウム,バナジウム,ホウ素,鉄,マグネシウム,アルミニウムである。X線結晶解析によれば,六方晶系同素体が主である。格子定数はa0=2.45Å,c0/2=3.36Åであり,graphitic炭素とは少し異なり,黒鉛化度p=0.32程度とみられる。常温の電気伝導性は人造黒鉛電解板に劣るが,土状黒鉛よりはよい。これより石灰窒素中炭素の性状は鱗状天然黒鉛と土状黒鉛との中間的なもので,人造黒鉛電解板に近く,やや劣る程度とみて差支えなかろう。