Synthesis
GENERAL STEPS: A solution of 7-methyl-4-phenyl-3,4-dihydrocoumarin (9.52 g, 40.0 mmol) in anhydrous tetrahydrofuran (50 mL) was added slowly and dropwise to a suspension of lithium aluminium hydride (3.04 g, 80 mmol) in anhydrous tetrahydrofuran (100 mL) cooled to 0 °C. The reaction mixture was stirred at room temperature and under inert atmosphere for 1 hour. Subsequently, 50 mL of a 1:1 mixture of tetrahydrofuran and water was added cautiously and acidified with 1 mol/L hydrochloric acid solution (150 mL) to quench the reaction. The reaction product was extracted with ethyl acetate and the organic phases were combined, washed sequentially with water and brine and dried over anhydrous magnesium sulfate. After removing the solvent under reduced pressure, 2-(3-hydroxy-1-phenylpropyl)-4-methylphenol (compound of formula II) was obtained in 97% yield (9.68 g). The product was recrystallized by diisopropyl ether to obtain a white powder. Melting point: 112-115 °C. 1H NMR (300 MHz, DMSO-d6): δ [ppm] = 2.08-2.17 (5H, m, CH3, CH2), 3.29-3.31 (2H, m, CH2), 4.38, 4.42 (2H, 2 xt, CH, OH), 6.63 (1H, d, J = 8.0 Hz, 1H- Ar), 6.76 (1H, dd, J = 8.3, 1.7 Hz, 1H-Ar), 7.00 (1H, d, J = 1.7 Hz, 1H-Ar), 7.08-7.13 (2H, m, 1H-Ph), 7.20-7.28 (3H, m, 4H-Ph), 9.04 (1H, s, OH). 13C NMR (300 MHz, DMSO-d6): δ [ppm] 20.5, 37.6, 39.1, 59.3, 115.0, 125.6, 127.0, 127.3, 127.9, 128.0, 130.9, 145.3, 152.4. ESI-MS: 243 [M + H]+.
References
[1] Patent: WO2006/66931, 2006, A1. Location in patent: Page/Page column 17
[2] Asian Journal of Chemistry, 2014, vol. 26, # 9, p. 2813 - 2814
[3] Tetrahedron Letters, 2008, vol. 49, # 23, p. 3790 - 3793
[4] Patent: US2006/79716, 2006, A1. Location in patent: Page/Page column 7
[5] Journal of Heterocyclic Chemistry, 2018, vol. 55, # 9, p. 2157 - 2167
