Chino Yijima

Anodic oxidation of vinyl sulphides. A convenient synthesis of α-thiolated aldehydes

Anodic oxidation of vinyl sulphides in aqueous acetonitrile gives α-thiolated aldehydes in good yields.

Base promoted oxidative decarboxylation of ethyl phenylglycinate via oxaziridine

Abstract Base catalyzed decompositions of 2-(α-ethoxycarbonyl-benzyl)-3-phenyl-oxaziridines carried out in benzene in an atmosphere of oxygen yielded N-benzoyl benzamides along with ethyl phenylglyoxylate imine and benzaldehydes.

Reactions of N-(1-cyanoalkyl)alkylideneamine N-oxides with dipolarophiles and nucleophiles. Part I. A novel synthesis of 2,4(5)-dialkyl-5(4)-phenylthioimidazoles

Reactions of N-(1-cyanoalkyl)alkylideneamine N-oxides with thiols at room temperature yielded 2,4,5-trisub-stituted imidazoles (I). The reaction was accelerated by addition of a small amount of piperidine, and inhibited when carried out above the melting temperature of the nitrone in a solvent. The mechanism is discussed.

NN-di-(1-cyanoalkyl)hydroxylamines. Part IV. Isolation of acyclic nitrones and their reaction with hydrogen cyanide

α-Hydroxyamino-nitriles react with aldehydes to give the corresponding crystalline N-alkylidene-N-(1-cyanoalkyl)N-oxides. These acyclic nitrones are monomeric and fairly stable. The reaction of the nitrones with hydrogen cyanide gives NN-di-(1-cyanoalkyl)hydroxylamines almost quantitatively.

Kinetics of aliphatic nitrone formation on the addition of N-alkyl-hydroxylamines to aliphatic aldehydes in aqueous solution

The formation of aliphatic nitrones from N-cyclohexylhydroxylamine and aldehydes has been followed spectro-photometrically in aqueous buffer solution of pH 1·5–9·4. The reaction is second-order at constant pH, being dependent on the free hydroxylamine concentration and the free aldehyde concentration. The second-order rate constant shows a linear dependence on [H+] below pH 7, but is independent of it above pH 8. From the values of the reaction constant, ρ*, the activation parameters ΔS‡ and Ea, and the known mechanism of several carbonyl reactions, a reaction scheme is proposed. Intermediate diol formation is a specific-acid-catalysed reaction and is rate-determining in acidic media, but the dehydration of the intermediate diol is rate-determining in alkali.

Polarographic analysis of aliphatic aldehydes with N-alkylhydroxylamines

メチル,イソプロピル,第3ブチルヒドロキシルアミンおよびα-ヒドロキシアミノバレロニトリルの4種を選び,水溶液中の脂肪族飽和アルデヒドとニトロンを生成させ,これらアルデヒドのポーラログラフ法による間接的な分析を目的として検討を行なった.(i)メチルおよび第3ブチルヒドロキシルアミンは満足な結果は得られなかった.(ii)イソプロピルヒドロキシルアミンは1.5×10-1Mの濃度のとき,pH3.0～4.0でアルデヒドの濃度が約10-5～10-3Mの範囲で波高との間に直線関係を示し,共存ケトンは10-2M以下の濃度ではまったく影響がなかった.(iii)α-ヒドロキシアミノバレロニトリルは1.0×10-1Mの濃度のとき,pH5.0～6.0でアルデヒドの濃度が約10-4～10-3Mの範囲で波高との間に直線関係を示した.共存ケトンはアルデヒド濃度の数倍以上となると無視できなくなり,両者の識別は困難であった。