Abstract:In this study, 4-hydroxy-3-methoxycinnamic acid and benzoyl chloride was reacted through the nucleophilic acyl substitution mechanism by using pyridine and triethylamine (TEA) as catalysts.This study aims to discern whether the 4-benzoyloxy-3-methoxycinnamic acid compound can be synthesized from 4-hydroxy-3-methoxycinnamic acid and benzoyl chloride by using pyridine and triethylamine (TEA) catalysts through microwave irradiation method. Also, this study is to discover which catalyst gives the most significant percentage of results in synthesizing 4-benzoyloxy-3-methoxycinnamic acid.This study was an experimental study, which synthesized 4-benzoyloxy-3-methoxycinnamic acid through microwave irradiation method at 180, 360, and 540 watts of power to determine the selected conditions of synthesis with pyridine catalyst.The results indicated that triethylamine (TEA) catalyst significantly gave a higher percentage of results (71.8%) than pyridine catalyst did (65.3%). The results were due to the inductive effect of ethyl on TEA and the effect of pyridine resonance associated with its basicity. The FT-IR spectrophotometry and the 1HNMR spectrometry profile confirmed that the product of both conditions was 4-benzoyloxy3-methoxycinnamic acid. The purity of the outcome of both reaction conditions was then determined by the melting point test and thin-layer chromatography (TLC), which revealed that the product was pure.The synthesis of 4-hydroxy-3-methoxycinnamic acid with benzoyl chloride pyridine catalyst can be carried out with microwave irradiation. Meanwhile, the synthesis with benzoyl chloride triethylamine (TEA) catalyst with microwave irradiation can only be performed at 540 watts of power. The catalyst with the more significant percentage of results, thus, is TEA catalyst with a percentage of 71.8%±1.3.