Synthesis and application of indole esters derivatives containing acrylamide group as antifouling agents

Two new indole ester derivatives containing acrylamide group were synthesized by Michael addition reaction and Friedel-Crafts reaction based on 5-bromo-1 H -indole. The synthesized compounds were characterized by 1 H Nuclearmagnetic Resonance Spectroscopy ( 1 HNMR) and Fourier Transform Infrared spectroscopy (FTIR). In the step of the Friedel-Crafts reaction, the optimum process conditions were determined as that the catalyst was AlCl 3 , the reaction time was 3 days and the reaction temperature was 25 °C. The results of minimal inhibitory concentration (MIC) of synthesized compounds showed that the two synthesized compounds have better antibacterial activity than reference. Algal inhibiting experiment shows that indole derivatives have better algae inhibition performance. Anti-protein adsorption experiment of antifouling paints with indole derivative and chlorothalonil as antifouling agents proves that indole derivatives exhibit better protein resistance behaviors. The antifouling paints using indole derivatives as antifouling agents have excellent antifouling properties after 24 months marine field test.