[Synthesis]
General procedure for the synthesis of 7-bromobenzodihydropyran-4-ol from 7-bromo-4-dihydrochromanone: sodium borohydride (545 mg, 14.4 mmol, 2.0 eq.) was added to a solution of 7-bromochroman-4-one (1.63 g, 7.2 mmol, 1.0 eq.) in methanol (10 mL), and the reaction mixture was stirred for 30 min at room temperature. Upon completion of the reaction, the solvent was removed by evaporation and the residue was purified by silica gel column chromatography (eluent: ethyl acetate/hexane = 1:2) to afford 7-bromobenzodihydropyran-4-ol (1.61 g, Yield: 98%) as a white solid.ESIMS (M+H-18): 211.0.1H NMR (400 MHz, CDCl3) δ: 7.17 (d, J = 8.0 Hz, 1H), 7.05-7.01 (m, 2H), 4.76-4.73 (m, 1H), 4.27-4.24 (m, 2H), 2.14-1.99 (m, 2H). |
[References]
[1] Patent: WO2015/89337, 2015, A1. Location in patent: Paragraph 0331 [2] Patent: US2013/18055, 2013, A1. Location in patent: Paragraph 0317-0318 [3] Patent: WO2017/58821, 2017, A1. Location in patent: Page/Page column 135; 136 |