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| 1.
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論文
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Fujii, Tozo ; Yoshida, Kiyoshi ; Ohba, Masashi ; Yoshifuji, Shigeyuki
概要:
The mercuric acetate-(ethylenedinitrilo) tetraacetic acid oxidation of 1-(3,4-dimethoxyphenyl)-2-(3-substituted piperidino) ethanols (7c-f), which carry the n-butyl, isopropyl, benzyl, and phenyl group as the 3-substituent in
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the piperidine ring, has been found to produce the corresponding 2- (8c-f) and 6-piperidones (12c-f) in good yields in ratios of 41 : 59,29 : 71,26 : 74,and 15 : 85. It is suggested that the 3-substituents exert both steric and electronic effects. The structures of the lactam alcohols (8c-f, 12c-f) have been confirmed by the chemical correlation with the known pyridones (11c-f, 15c-f) through the lactams (10c-f, 14c-f). The starting piperidinoethanols (7c-f) have been synthesized from the 3-substituted pyridines (5c-f) by quaternization with 3,4-dimethoxyphenacyl bromide followed by catalytic and sodium borohydride reductions.
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| 2.
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論文
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Fujii, Tozo ; Ohba, Masashi ; Yoshifuji, Shigeyuki ; Kirihara, Makoto
概要:
In the alkaline ferricyanide oxidation at 32°of 3-substituted 1-(3,4-dimethoxyphenethyl) pyridinium bromides (type 3), t
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he hydroxymethyl, N, N-dimethylaminomethyl, carbamoyl, and 1,1-ethylenedithioethyl groups at the 3-position have been found to orient the oxidation to both the 2-(type 4) and the 6-position (type 5) in ratios of 70 : 30,26 : 74,50 : 50,and 4 : 96. The carboxyl or 1,1-ethylenedioxyethyl group at the 3-position has oriented the oxidation to the 6-position exclusively, and possible factors in determining the regioselectivity in the ferricyanide oxidation of the 1,3-disubstituted pyridinium salts are discussed. For preparation of additional pyridone derivatives, 1-(3,4-dimethoxyphenethyl)-5-carboxy-2(1H)-pyridone (5d) was esterified with methanolic hydrogen chloride to the methyl ester (5h), and 1-(3,4-dimethoxyphenethyl)-5-(1,1-ethylenedioxyethyl)-2 (1H)-pyridone (5e) was converted into the methyl ketone (5i) by acid hydrolysis. The structures of the pyridones (4a, b, c, f, 5a-i) thus prepared have assigned on the basis of their ultraviolet, infrared, and nuclear magnetic resonance spectra.
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| 3.
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論文
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Fujii, Tozo ; Yoshifuji, Shigeyuki ; Ohba, Masashi
概要:
3,4-Dimethoxy, 3-benzyloxy-4-methoxy, 3,4,5-trimethoxy, 2-hydroxy-3,4-dimethoxy, and 2-benzyloxy-3,4-dimethoxy derivatives (3a-e) of phenacyl bromide have been prepared in 44-84% yields from the corresponding acetophenones by bromination
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with bromine in a mixture of ether and chloroform.
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| 4.
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論文
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Fujii, Tozo ; Yoshida, Kiyoshi ; Ohba, Masashi ; Mitsukuchi, Morihiro ; Tanaka, Izumi ; Yoshifuji, Shigeyuki ; Kirisawa, Makoto
概要:
The alkaline ferricyanide oxidation at 32°of 1-(3,4-dimethoxyphenethyl) pyridinium bromides (3c-f) carrying the n-butyl,
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isopropyl, benzyl, and phenyl group at the 3-position has been found to produce the corresponding 2-(4c-f) and 6-pyridones (5c-f) in ratios of 74 : 26,71 : 29,69 : 31,and 13 : 87. In the case of the 3-benzyl derivative (3e), 1-(3,4-dimethoxyphenethyl)-5-benzoyl-2 (1H)-pyridone (5g) has also been obtained in 1% yield. On the basis of the present and earlier data, possible factors in determining the orientation in the ferricyanide oxidation of 1,3-disubstituted pyridinium salts are discussed.
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| 5.
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論文
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Fujii, Tozo ; Hiraga, Takashi ; Ohba, Masashi
概要:
In the oxidation of 3-substituted 1-methylpyridinium salts (type III) with potassium ferricyanide and KOH at 32℃, the is
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opropyl and the tert-butyl group at the 3-position were found to orient oxidation to both the 2-(type IV) and the 6-position (type V) in ratios of 71 : 29 and 14 : 86,respectively. In the oxidation of the 1-methyl-3-tert-butyl-pyridinium salt (IIIl), replacement of the 1-methyl group by an aralkyl group along the series benzyl, phenethyl, and 3,4-dimethoxyphenethyl decreased the extent of the 2-pyridone formation along the series.
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| 6.
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論文
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Fujii, Tozo ; Ohba, Masashi ; Kogen, Hiroshi ; Ueda, Yuko
概要:
The thermal decarboxylation of some unsaturated acids (1,5,6,8,and 9) incorporated into six-membered lactams was examine
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d. Although 8 and 9 did not undergo decarboxylation when heated neat at 175-180℃ and 240-245℃, respectively, for 2 h, 1,5,and 6 were decarboxylated in 1,1,2,2-tetrachloroethane at 135℃. The relative ease of the reaction was in the order of 1≥6≫5. In the case of 1,the rate-decreasing effects observed on dilution and on the addition of trichloroacetic acid suggest the reaction to be a dimeric intermolecular process.
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