The Synthesis of Flavons Compounds Using Imidazolium-Based Ionic Liquid Using The Microwave Irradiation Method And Its Application In Practicum Modules for Senior High School/Its Equivalents
Allysa Pratiwi Putri (a), Deana Wahyuningrum (a)

Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung
*deana[at]itb.ac.id

Abstract

This research used the reaction of the flavone compounds synthesis with ionic liquids as a mediator using the MAOS (Microwave-Assisted Organic Synthesis) method. The ionic liquids were used as a medium because they have a relatively high solubility in organic and inorganic compounds. Another advantage of ionic liquids is that they can be recycled and are environmentally friendly to support the concept of green chemistry. The ionic liquid medium used was [BMIM]Cl, [DMIM]Br, and [EMIM]Br. The ionic liquids were synthesized by reacting haloalkanes (n-chlorobutane, n-bromodecane, n-bromoethane) and 1-methylimidazole in a ratio of 1:1 with the aid of microwave radiation power. TLC, FT-IR and NMR characterized the formed ionic liquid. Then purified by esterification and followed by distillation. The ionic liquids synthesis takes place at a temperature varying from 50 oC to 80 oC for 21 to 80 minutes. The resulting ionic liquids are [BMIM]Cl, [DMIM]Br, and [EMIM]Br, with the yields obtained are 24%, 87%, and 48%, respectively. The TLC test for imidazolium ion liquid carried out in chloroform: methanol (9:1, v/v) eluent system gave a different Rf value than the precursors. Based on the FT-IR spectrum measurements, the imidazolium-based ionic liquids have typical vibrational peaks of the C-N group at wavenumbers of 1164 cm-1 to 1184 cm-1, and the vibration of the C=N group at a wavenumber of 1570 cm-1. The results of the 1H NMR spectra (500 MHz, CDCl3) of the imidazolium-based ionic liquids showed typical singlet proton signals of the aromatic groups (&#61540-= 7.5-10.5 ppm) and proton signals of the aliphatic groups (&#61540-= 1.3-4.2 ppm). The flavone compounds were synthesized by reacting a ditone compound (1-(2-hydroxyphenyl)-3-phenyl-1,3-propandione) in the medium of imidazolium-based ionic liquids using the MAOS method. The research results were used to develop a chemistry practicum module for high school/equivalent students to improve their comprehension of organic chemistry topics.

Keywords: Flavones, imidazolium-based ionic liquids, MAOS, method, 1-(2-hydroxyphenyl)3-phenyl-1,3-propandione, chemistry practicum module

Topic: CHEMISTRY AND MATERIAL SCIENCES