Synthesis
General procedure for the synthesis of 2-bromoindene from 2-bromo-1-indanol: In a 25 mL round-bottomed flask, 250 mg (1.2 mmol) of 2-bromo-1-phenylethanol (1a), 50 mg (20 wt%) of H-β zeolite and 1.0 mL of chlorobenzene were added. The reaction flask was heated in an oil bath at 120 °C for 6 h. The reaction process was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the flask was cooled to room temperature and the reaction mixture was filtered through Wattman filter paper and the filter cake was washed with 10 mL of diethyl ether. The filtrate was concentrated under reduced pressure to remove the solvent. The resulting crude product was purified by column chromatography on silica gel (200-400 mesh) to afford 2-bromoindene (2a, 0.16 g) in 72% yield using hexane as eluent.
References
[1] Tetrahedron Letters, 2014, vol. 55, # 10, p. 1793 - 1795
[2] Patent: US2016/194422, 2016, A1. Location in patent: Paragraph 0129; 0138
[3] Journal of Organic Chemistry, 1982, vol. 47, # 4, p. 705 - 709
[4] Patent: EP2390249, 2011, A2. Location in patent: Page/Page column 20-21
[5] Journal of Medicinal Chemistry, 2006, vol. 49, # 7, p. 2222 - 2231
