Solid-liquid reaction catalyzed by a liquid containing rich phase-transfer catalyst—Synthesis of hexyl acetate

This work is for the purpose of evaluating the feasibility of synthesizing hexyl acetate (ROAc) from n-hexyl bromide (RBr) and sodium acetate (NaOAc) by a novel phase-transfer catalysis (PTC) technique. In this new technique, the solid-liquid reaction was catalyzed by a catalyst-rich liquid phase. Experimental results reveal that the use of this technique for synthesizing ROAc gives a far higher reaction rate than the solid-liquid-PTC does and a slightly faster rate than tri-liquid PTC. The amount of water added greatly influences the type of the reaction system and the reaction rate. The kind of catalyst affects the conversion of RBr and the fractional yield of ROAc significantly. The catalyst with a longer chain length gives a better performance. However, it will more easily dissolve in the organic phase and hence is more difficult to be recovered and reused after reaction. Tetra-n-butylammonium bromide is the best choice. As the experimental results of reusing catalyst phase show that the conversion decreases due to part of catalyst dissolving into the organic phase, an effort for improving this drawback should be made in the future.