(4S)-5,5-Diphenyl-4-(propan-2-yl)-1,3-oxazolidin-2-one → (S)-2-Amino-3-methyl-1,1-diphenylbutane

関与物質

反応手順

A solution of (S)-4-isopropyl-5,5-diphenyl-2-oxazolidinone (3) (2.9 g, 10.31 mmol) in MeOH/AcOH and a 10% Pd (435 mg, 4.09 mmol) on activated carbon was shaken for 68 h under 4–5 atm pressure of hydrogen at room temperature. The catalyst was filtered off over Hyflo Super Cell and organic solvents were evaporated under reduced pressure. The resulting residue was treated with HCl (2.0 M, 50 ml), stirred for 2 h at room temperature, made basic with NaOH pellets, and saturated with K2CO3 and NaCl. Organic compounds were then extracted into AcOEt (3×100 ml), dried over MgSO4/K2CO3 and concentrated under reduced pressure to obtain a crude product. Re-crystallisation from petroleum ether gave the title compound (4) (1.79 g, 72%) as a light-brown solid. m.p. 71–72° C. [α]D25=−4.19° (c, 0.1097 in CHCl3). δH 0.78 (3H, d, 3J=6.60 Hz, CH3), 0.91 (3H, d, 3J=7.20 Hz, CH3), 1.26 (2H, broad s, NH2), 1.62 (1H, ds, CHMe2), 3.45 (1H, dd, 3J=10.5 and 2.40 Hz, CH—NH2), 3.70 (1H, d, 3J=10.5 Hz, CH—Ph2), 7.00–7.40 (10H, m, Ar—H). δC 14.2 and 21.5 (CH3), 28.9 (CH—Me2), 58.1 and 58.9 (CH—NH2 and CH—Ph2), 126.5, 126.7, 128.2, 128.5, 128.8 and 129.0 (o-, m- and p-Ar), 143.5 (2×α-Ar). Anal. Calcld for C17H21N: C 85.30; H 8.84; N 5.85. Found: C 85.12; H 8.91; N 5.96. ir 3361 (NH2). m/e (CI—CH4) 240 (MH+, 8%), 72 (100%).

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