Synthesis
Step I: Sodium borohydride (5.20 g, 0.137 mol) was added batchwise to a solution of 4-bromo-2-thiophenecarboxaldehyde (25.0 g, 0.131 mol) in anhydrous tetrahydrofuran (400 mL). The reaction mixture was stirred at room temperature for 1.5 hours. Upon completion of the reaction, saturated ammonium chloride solution (100 mL) was slowly added to quench the reaction. Subsequently, the reaction mixture was extracted with ethyl acetate and the organic phases were combined and washed with saturated brine. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford (4-bromo-2-thienyl)methanol (25.02 g, 99% yield), and the product could be used for subsequent reactions without further purification. NMR hydrogen spectrum (400 MHz, CDCl3): δ = 1.93 (broad single peak, 1H), 4.79 (single peak, 2H), 6.93 (single peak, 1H), 7.18 (double peak, J = 1.5 Hz, 1H).
References
[1] Journal of the American Chemical Society, 2007, vol. 129, # 24, p. 7523 - 7530
[2] Bioorganic and Medicinal Chemistry Letters, 2012, vol. 22, # 4, p. 1788 - 1792
[3] Synthesis, 1983, # 1, p. 73 - 75
[4] Patent: WO2013/110643, 2013, A1. Location in patent: Paragraph 00212; 00213
[5] Bioorganic and Medicinal Chemistry, 2008, vol. 16, # 4, p. 1992 - 2010
