Synthesis, Characterization and Antimicrobial Assessment of 3, 4, 5-Trimethoxy-3’, 4’-Dimethoxychalcone and 2, 4, 6-Trimethoxy-3’, 4’-Dimethoxychalcone

Background: Chalcones have been utilised in the synthesis of different heterocyclic molecules with antimicrobial activity. Aims: This study aims to synthesise, characterise and screen 3, 4, 5-trimethoxy-3’, 4’-dimethoxychalcone and 2, 4, 6-trimethoxy-3’, 4’-dimethoxychalcone for antimicrobial property. Methods: 3, 4, 5-trimethoxy-3’, 4’-dimethoxychalcone was synthesized from Claisen-Schmidt condensation reaction between 3, 4-dimethoxyacetophenone and 3, 4, 5-trimethoxybenzaldehyde in the presence of 50 % potassium hydroxide at room temperature and subsequently neutralised with 50 % acetic acid. Similarly, 2, 4, 6-trimethoxy-3’, 4’-dimethoxychalcone was produced through the reaction between 3, 4-dimethoxyacetophenone and 2, 4, 6-trimethoxybenzaldehyde in the presence of 50 % potassium hydroxide for 2 hrs at 70 oC and consequently neutralised by 50 % acetic acid. Purity was evaluated by melting point determination and thin layer chromatography (TLC). Characterization was done using UV and IR spectroscopy, 1HNMR, 13CNMR, Mass spectroscopy and Elemental Analysis. Result: The compounds were screened for antimicrobial activity. 3, 4, 5-trimethoxy-3’, 4’-dimethoxychalcone was obtained as yellow crystal (melting point 121-122 oC, percentage yield 46 %) through the condensation reaction between 3,4-dimethoxyacetophenone and 3, 4, 5-trimethoxybenzaldehyde. While 2, 4, 6-trimethoxy-3’, 4’-dimethoxychalcone a yellow crystal (melting point 150-151 oC, percentage yield 41%) was synthesised by reacting 3, 4-dimethoxyacetophenone and 2, 4, 6-trimethoxybenzaldehyde. Conclusion: Both synthesised chalcones do not have appreciable antimicrobial activity.