Synthesis of 2-Phenoxyisobutyric Acid Ethyl Ester by Tri-liquid-Phase Catalysis. 2. Analysis of Factors Affecting the Reactions in a Batch Reactor

以三液相催化技術合成2-苯氣基異丁酸乙酯 2.影響批式反應的變因分析

蕭旭欽(Hsu-Chin Hsiao) ； 翁鴻山(Hung-Shan Weng)

《Journal of the Chinese Institute of Chemical Engineers》 31卷6期 (2000/11) Pp. 573-583

https://doi.org/10.6967/JCICE.200011.0573

摘要

本文為以三液相催化技術合成2-苯氣基異丁酸乙酯（ROPh）之研究系列的第二部份，主要在探討各變因對以溴化正四丁基銨（QBr）為相間轉移觸媒，催化2-溴異丁酸乙酯（RBr，有機相受質）與酚化鈉（NaOPh，水相親核試劑）反應的影響。批式反應溫度範圍為40～80℃，攪拌速率固定在1000rpm，反應進行150分鐘。實驗結果發現，NaOPh及QBr總添加量對反應結果的影響較小，但NaOPh與QBr莫耳分率的效應較大。當QBr莫耳分率為0.3時，所得的轉化率及生產物生分率最高。此外，在系統中添加少量的碳酸鈉可得較高的轉化率及主產物主成分率。而提高反應溫度雖可提高轉化率及主產物生成分率，但為避免觸媒分解及有機溶劑揮發，溫度也不宜過高，以70℃左右為最適宜。若與等觸媒用量的液-液型相間轉移催化的反應結果比較，三液相催化所得的主產物主成分率雖略低，但反應速率較快且觸媒容易回收再使用。

並列摘要

As the second part of a series of studies on the synthesis of 2-phenoxyisobutyric acid ethyl ester (ROPh) by tri-liquid-phase catalysis, this work examines the factors affecting the reaction between 2-bromoisobutyric acid ethyl ester (RBr, organic substrate) and sodium phenolate (NaOPh, aqueous nucleophile) with tetra-n-butylammonium bromide (QBr) as a phasetransfer catalyst. The reaction is performed in a batch reactor at 40-80℃ for 150 minutes while the agitation speed is fixed at 1000 rpm. Experimental results indicate that the total amount of NaOPh and QBr only slightly affects the reaction, while the individual mole fractions of these components exert significant influence. When the mole fraction of QBr is 0.3, both the conversion of RBr and the fractional yield of the desired product (ROPh) are maximal. The addition of a small amount of Na2CO3 will result in a higher conversion and fractional yield. Furthermore, a high reaction temperature enhances the conversion and the fractional yield; as long as the temperature is not so high as to cause thermal decomposition of the catalyst and vaporization of the organic solvent. The optimal temperature is about 70℃. Although the fractional yield by tri-liquid-phase catalysis is slightly lower than that observed with the same amount of catalyst in convention liquid-liquid phase-transfer catalysis, the reaction rate is higher and the catalyst can be easily re-used in the fanner case.

並列關鍵字

2-Bromoisobutyric Acid Ethyl Ester ； Sodium Phenolate ； Tetra-n-butylanunonium Bromide ； Phase-transfer Catalyst ； Third Liquid Phase ； Tri –liquid-phase Catalysis