ゲンチヂン酸の合成 (第1報)
ハイドロヒノン並びに其のモノメチルエーテルのカルボキシル化
1951 年 71 巻 9 号 p. 958-961
詳細
1951 年 71 巻 9 号 p. 958-961
In the high pressure carboxylation of hydroquinone in glycerol solution with potassium bicarbonate and carbon dioxide gas, not the increase of pressure but the prolongation of reaction time influences the yield of gentisic acid, although the yield is generally poor. The increase of reaction temperature, however, promotes the formation of by-product dicarboxylic acid, which was proved to be 2, 5-dihydroxyterephthalic acid by the comparison of its methylated product with an authentic specimen. The carboxylation by this process is assumed to be the rearrangement mechanism similar to Kolbe's reaction. The fact that the formation of dicarboxylic acid was not evidenced in the carboxylation of hydroquinone monomethyl ether endorses this assumption but the increase of reaction temperature rather decreases the yield of monocarboxylic acid.
