Microwave-Assisted Synthesis of Ethyl 4-Hydroxy-3-ethoxycinnamate Through A Catalytic Pathway Utilizing Cationic Exchange Resin

摘要

Ethyl 4-hydroxy-3-methoxycinnamate was synthesized by reaction of ethanol and 4-hydroxy-3-methoxycinnamic acid using an efficient cation-exchange resin as catalyst under microwave irradiation. The catalyst activity was investigate by single factor experiments. The reaction conditions - amount of catalyst, microwave irradiation time, microwave power and alcohol/acid ratio - were investigate by single factor experiments and orthogonal experiments. The optimal reaction conditions are as follow: 4-hydroxy-3-methoxycinnamic acid 0.1mol; molar radio of ethanol to 4-hydroxy-3-methoxycinnamic acid 5:1; percentage weight of resin 30%; microwave power 300W; irradiation time 30 min. Yield of the reaction was 84.2% under the optimal conditions. The catalyst is recyclable and the yield remained over 78% after recycling the catalyst for 5 times.