- 期刊
苯甲酸酯及桂皮酸酯之試製
Preparation of Benzoic Acid Esters and Cinnamic Acid Esters
摘要
桂皮酸脂及苯甲酸酯均有特別悅人之香味及溫和之殺菌、防黴、殺蟲等特性，廣用於香料工業，防腐劑及驅蟲劑等方面。本試驗係用純硫酸爲接觸劑使醇與酸行酯化試製數種酸之酯。取200公撮純甲酵，60公克苯甲酸公撮純硫酸，廻流反應7小時，苯甲酸甲酯之產率可述92.7%。250公撮無水酒精，50公克苯甲酸和6公撮純硫酸，廻流4小特，苯甲酸乙脂之產率可並88.6%，160公撮之90%酒精，60公克苯甲酸，160公攝苯和公撮純硫酸，脫水與酯化同時進行，廻流27.5小時，苯甲酸乙醋之產率可達96.6%。100公撮純甲醇，30公克桂皮酸，與5公撮純酸廻流12小時，粗桂皮酸甲酯之產率可遠99.6%。160公撮無水酒精，40公克桂皮酸和5公撮純硫酸，廻流12小時，桂皮酸乙酯之生產率可達87%。苯甲酸芐脂，可由氯化苄與苯甲酸鈉藉三乙胺之觸媒作用而合成，其最適反應條件爲：氯化芐0.7克分子，苯甲酸鈉0.5克分子，三乙胺1.7公撮，反應溫度及時間分爲三級（95 ℃；2小時。120-135℃；2小時。小於140℃；半小時）。其產率可達96.9%；是法用三乙胺爲觸媒，尚屬一新頴之方法。依本實驗結果知：用工業酒精與苯甲酸行酯化，然後用苯脫水以製甲酸乙酯法，和用三乙胺為接觸劑以製苯甲酸芐醋法，最適工業上之應用。
關鍵字
無資料並列摘要
Cinnamic acid esters and benzoic esters possess distinctive agreeable odors and mild antiseptic, germicidal. mould-preventing properties, which make them valuable as ingredients of perfume, antiseptics and insecticides. In this experiment the authors, using pure sulfuric acid as catalyst, investigated the optimum conditions for preparing several esters of these two acids. The following are some pertinent data: 1. Poured 200 cc of pure methyl alcohol to 60 gr. of benzoic acid and 8 cc of pure suIfuric acid, let the mixture reflux for seven hours. the yield of methyl benzoate reached 92.7% ; 2. To 250 cc of absolute alcohol added 50 gr. of benzoic acid and 6 cc of pure sulfuric acid. the mixture was refluxed for four hours, the yield of ethyl benzoate was 88.6%; 3. Poured 160 cc of 90% ethyl alcohol to 60 gr. of benzoic acid, added to the mixture 160 cc of benzene and 3 cc of pure sulfuric acid, so as to let dehydration and esterifiction proceed simultaneously, after refluxing the mixture for 27.5 hours. the yield of ethyl benzoate reached 98% ; 4. Added roo cc of pure methyl alcohol to 30 gr of cinnamic acid, then added to the mixture 5 cc of pure sulfuricacid let the mixture reflux for 12 hours, the yield of crude methyl cinnamate was 99.6%; 5. Poured 160 cc of absolute ethanol to 40 gr. of cinnamic acid, added to the mixture 5 gr. of pure sulfuric acid, after refluxing the mixture for 12 hours the yield of ethyl cinnamate was 87%, Benzyl benzoate was also prepared by allowing benzyl chloride to contact with sodium benzoate using triethylamine as catalyst. The preferential conditions were found to be: benzyl chloride. 0.7 gram molecular weight; sodium benzoate 0.5 gram molecular weight; triethylamine. 1.7 cc ; the reaction temperature was to be maintained at 95℃ for two hours. between 120℃ and I35℃ for two hours, at 140°C for one half hour. From this experiment, we can conclude that Ethyl benzoate could be successfully prepared by allowing commercial grade ethanol to react with benzoic acid, using benzene as a dehydrating agent ; Triethylamine as a catalyst for preparing benzyl benzoic is recommended as industrially feasible.