Cesium carbonate → t-butyl (1R)-2-hydroxy-1-(4-(2-methylpentyloxy)phenyl)ethylcarbamate

関与物質

反応条件

反応手順

[(R)-2-Hydroxy-1-(4-hydroxy-phenyl)-ethyl]-carbamic acid t-butyl ester (0.700 g 2.77 mmol), 2-methylpentyl bromide (0.548 g, 3.32 mmol) and Cs2CO3 (1.17 g, 3.59 mmol) were combined in DMF (15 ml). The reaction mixture was heated at 70° C. overnight. Saturated NH4Cl was added to quench the reaction. The aqueous layer was extracted with ethyl acetate (3×10 ml). The combined organic layers were washed with brine, then dried over MgSO4, filtered and concentrated to give a white crude solid. The crude product was purified via column chromatography on silica gel (0%-50% ethyl acetate in hexanes) to afford the title compound (0.705 g, 76% yield of 2 steps) as a white solid: 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.21 (d, 2H), 6.89 (d, J=8.6 Hz, 2H), 5.18 (d, J=7.1 Hz, 1H), 4.72 (br. s., 1 H), 3.81 (dd, J=9.0, 5.7 Hz, 3H), 3.72 (m, 1H), 3.49 (s, 2H), 2.54 (br. s., 1H), 1.95 (m, 1H), 1.35 (m, 11H), 1.02 (d, J=6.8 Hz, 3H), 0.93 (m, 3H); LCMS (ESI) m/e 338.2 [(M+H), calcd for C19H32NO4 338.5].

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