Synthesis 3-Acetyl Coumarin via Knoevenagel Condensation Under Microwave Irradiation
Reyhan Syifa, Hanhan Dianhar, Fera Kurniadewi, Zulhipri

Chemistry Study Program, Faculty of Mathematics and Natural Sciences
Universitas Negeri Jakarta, Jalan Rawamangun Muka, Kel. Rawamangun
East Jakarta 13220, Indonesia.

Abstract

Coumarin is a therapeutic agent that can be found naturally as secondary metabolite in plants, bacteria, fungi, essential oils and can be chemically synthesized. The Knoevenagel reaction is one of the most useful C=C bond formation processes involving the condesation between benzaldehyde and activated methylenes in the presence of an amine. The Knoevenagel reaction is commonly used to synthesize coumarin. This study aimed to synthesize 3-acetyl coumarin and determine the structure analysis. In this research, 3-acetylcoumarin was obtained from 2-hydroxy benzaldehydes and ethyl acetoacetate at molar ratio 1.2:1 in the presence of diethylamine as a catalyst via Knoevenagel reaction under microwave irradiation for 60 s. The purity of obtained 3-acetyl coumarin was investigated by Thin Layer Chromatography and melting point test then characterized by UV-vis and NMR spectroscopy for further structure analysis. It was found that the melting point of the obtained 3-acetyl coumarin around 120-122oC. In conclusion, this method can be used to synthesize 3-acetyl coumarin in shorter reaction time than conventional method.

Keywords: 2-hydroxy benzaldehyde, coumarin, knoevenagel condesation, microwave irradiation, synthesis

Topic: Chemistry