芳香族力ルボン酸に関する研究(第1報) : メチルナフタリンの重クロム酸ナトリウム水溶液加圧酸化によるナフトエ酸の合成

概要

論文の詳細を見る
Oxidation of methylnaphthalenes with aqueous sodium bichromate under pressure was carried out to obtain naphthoic acids. β-naphthoic acid obtained from β-methylnaphthalene was extremely pure. The yield was about 900% and independent on the reaction temperatures between 230°c and 270deg;c when the reaction was carried out under 20 atm CO2 pressure. But without CO2 addition the yield was depressed to 70-80%. As the Oxidizing ability of bichromate is considerably lowered in strong alkaline solution, carbon dioxide was used to neutralize the sodium hydroxide produced during the reaction, thus keeping the reaction medium nearly neutral. Molar ratio of bichromate to methylnaphthalene above 1.2 was necessary to obtain the high yield. The concentration of bichromate above 25% gave poor result, especially when the reaction was carried out at low bichromate ratio without CO2. Oxidation of crude methylnaphthalene oil gave the mixture of naphthoic acids, and the molar ratio of β- to α-naphthoic acid was established as about 2 from the melting point curve.
社団法人有機合成化学協会の論文