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Ethyl 5-aminobenzofuran-2-carboxylate is used as an synthetic intermediate in the preparation of indolebutylpiperazines, a class of dual 5-HT1A receptor agonists and serotonin reuptake inhibitors. Ethyl 5-amino-1-benzofuran-2-carboxylate was also used as a potential radiolabelled analog for melanoma imaging and targeted radiotherapy.

General procedure for the synthesis of ethyl 5-aminobenzofuran-2-carboxylate from ethyl 5-nitrobenzofuran-2-carboxylate: 20.0 g of ethyl 5-nitrobenzofuran-2-carboxylate was placed in a reaction flask and 300 mL of ethanol was added as a solvent. Subsequently, 2 g of 5% Pd/C catalyst was added. The reaction system was replaced twice with hydrogen to ensure that the reaction environment was a hydrogen atmosphere. The hydrogenation reaction was carried out for 3 hours by adjusting the hydrogen pressure to 0.3-0.5 MPa and controlling the reaction temperature in the range of 10-30°C. The reaction was carried out by filtration. Upon completion of the reaction, the catalyst was removed by filtration. The filtrate was concentrated under reduced pressure and dried to give 17.1 g of ethyl 5-aminobenzofuran-2-carboxylate in 98% yield.

[1] Patent: WO2013/153492, 2013, A2. Location in patent: Page/Page column 23
[2] Patent: US2015/87835, 2015, A1. Location in patent: Paragraph 0125
[3] ChemCatChem, 2014, vol. 6, # 11, p. 3153 - 3159
[4] Patent: CN107674052, 2018, A. Location in patent: Paragraph 0035-0037
[5] Patent: CN107540646, 2018, A. Location in patent: Paragraph 0041; 0042; 0043