The Synthesis of Ethyl-1-Benzyl-5-Methyl-1H-1,2,3-Triazoles-4-Carboxylate Using Microwave Assisted Organic Synthesis Method and Determination of its Corrosion Inhibition Activity on Carbon Steel

Abstract

This study has successfully conducted the development method of synthesizing ethyl-1-benzyl-5-methyl-1H-1,2,3-triazoles-4-carboxylate utilizing Microwave Assisted Organic Synthesis (MAOS) method. Synthesis has been carried out in two stages. The first stage was the formation of benzyl azide (1) from the reaction between sodium azide and benzyl bromide using conventional method. In the second stage, product 1 was reacted with ethyl acetoacetate in the catalytic base of potassium carbonate using MAOS method to form ethyl-1-benzyl-5-methyl-1H-1,2,3-triazoles-4-carboxylate (2) with melting point of 75-77 °C and chemical yields of 37.5%. Measurement of compound 2 using mass spectroscopy TOF MS ES+ showed peak at 245.1244 corresponding to molecular formula C13H15N3O2. Structure elucidation has been confirmed through IR, 1H NMR, and 13C NMR spectroscopies. Corrosion inhibition test of compound 2 was conducted using Electrochemical Impedance Spectroscopy (EIS) on carbon steel in 1% (w/v) NaCl saturated with CO2. The largest corrosion inhibition efficiency of 2 was obtained at 45 °C and the concentration of 70 ppm, which is 91.54%. The ∆Gadsvalue of compound 2 at room temperature is 38.48 kJ/mole which corresponds to the semi-chemisorption or semi-physiosorption mechanism of compound 2 on the metal surface according to Langmuir adsorption isotherm.