Iodoethane → (R)-Ethyl 4-(4-bromophenyl)-3-((tert-butoxycarbonyl)amino)butanoate

Beteiligte Stoffe

Reaktionsschritte

To a suspension of (R)-4-(4-bromophenyl)-3-(tert-butoxycarbonylamino)butanoic acid (9.98 g, 27.9 mmol) and NaHCO3 (4.68 g, 55.7 mmol) in DMF (45 mL) is added Ethyl iodide (6.75 mL, 84 mmol) at room temperature under nitrogen. After stirring for 71 hours, the reaction is quenched with H2O (300 mL), and then precipitated solid is collected and washed with H2O (500 mL) to give (R)-ethyl 4-(4-bromophenyl)-3-(tert-butoxycarbonylamino)butanoate (10.25 g, 94%). HPLC retention time=1.48 minutes (condition B); MS (ES+)=329.9 (m-tBu+2); 286.0 (m-Boc+2; 100%); 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.27 (t, J=7.2 Hz, 3 H) 1.40 (s, 9 H), 2.43 (A of ABX, Jab=15.8 Hz, Jax=5.7 Hz, 1 H) 2.50 (B of ABX, Jab=15.8 Hz, Jbx=5.4 Hz, 1 H) 2.74-2.90 (m, 2 H) 4.11 (br s) 4.15 (q, J=7.1 Hz, 2 H) 5.04 (br d) 7.07 (d, J=8.3 Hz, 2 H) 7.40-7.43 (m, 2 H).

Herkunft & Nachweise