Synthesis
General procedure for the synthesis of 1-(5-bromofuran-2-yl)ethanone using 2-acetylfuran as starting material: under stirring conditions, N-bromosuccinimide (22 mmol) was added batchwise to a solution of 2-acetylfuran (20 mmol) in DMF (20 mL). The reaction mixture was stirred at room temperature overnight before it was poured into cold water to terminate the reaction. Subsequently, the product was extracted with ether (200 mL in three portions). Upon treatment, the target compound 1-(5-bromofuran-2-yl)ethanone was obtained in 61% yield and with a melting point of 92-93 °C (melting point of 94-95 °C after recrystallization from hexane/ethyl ether; for literature values see Gilman H., et al., J. Am. Chem. Soc., 53, 4192-4196 (1931)). The nuclear magnetic resonance hydrogen spectrum (1H NMR, CDCl3) data for the product were as follows: δ 2.45 (s, 3H), 6.49 (d, J = 3.9 Hz, 1H), 7.12 (d, J = 3.6 Hz, 1H). The nuclear magnetic resonance carbon spectrum (13C NMR) data are as follows: δ 185.4, 154.4, 128.2, 118.9, 114.3, 25.7.
References
[1] Journal of Natural Products, 2017, vol. 80, # 9, p. 2561 - 2565
[2] Journal of Medicinal Chemistry, 2004, vol. 47, # 14, p. 3658 - 3664
[3] Patent: US2005/282853, 2005, A1. Location in patent: Page/Page column 15; 19
[4] Bioorganic and Medicinal Chemistry Letters, 2016, vol. 26, # 7, p. 1784 - 1788
[5] Organic Letters, 2017, vol. 19, # 21, p. 5976 - 5979
