Benzyl Bromide → (R)-benzyl 4-(4-bromophenyl)-3-(tert-butoxycarbonylamino)butanoate

Beteiligte Stoffe

Reaktionsschritte

To a suspension of (R)-4-(4-bromophenyl)-3-(tert-butoxycarbonylamino)butanoic acid (5.02 g, 14.01 mmol) and NaHCO3 (3.53 g, 42.0 mmol) in DMF (20 mL) is added Benzyl bromide (5.10 mL, 42 mmol) at room temperature under nitrogen. After stirring for 46 hours, the reaction is diluted with H2O (200 mL), and then precipitated solid is collected and washed with H2O (500 mL) and then with heptane (200 ml) to give (R)-benzyl 4-(4-bromophenyl)-3-(tert-butoxycarbonylamino)butanoate (5.61 g, 89%). HPLC retention time=1.56 minutes (condition B); MS (ES+)=392.1 (m-tBu+2); 348.1 (m-Boc+2; 100%); 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.39 (s, 9 H) 2.48 (A of ABX, Jab=15.9 Hz, Jax=5.6 Hz, 1 H) 2.54 (B of ABX, Jab=15.9 Hz, Jbx=5.3 Hz, 1 H) 2.72-2.88 (m, 2 H) 4.11 (br s, 1 H) 5.02 (br s, 1 H) 5.10 (A of AB, J=12.1 Hz, 1 H) 5.16 (A of AB, J=12.1 Hz, 1 H) 7.00 (d, J=8.1 Hz, 2 H) 7.34-7.39 (m, 7 H).

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