反应详情

To a stirred solution of (S)-4-Amino-5-(3′-chloro-biphenyl-4-yl)-2-methyl-pentanoic acid ethyl ester hydrochloric acid salt (200 mg, 0.52 mmol) and dihydrofuran-2,5-dione (68 mg, 0.68 mmol) in 8 ml CH2Cl2 was added pyridine (0.17 ml, 2.1 mmol) and the solution was stirred for 2 hours. The reaction mixture was acidified to pH=3 with 1M HCl. Solvent was removed under reduced pressure and the residue was purified by preparatory HPLC (DAICEL CHIRALCEL OD-H 21×250 mm column, 18 ml/min, 90% heptane 10% EtOH+0.1% TFA), collected a peak at 3.9 minutes, to give 50 mg (2R,4S)-4-(3-carboxy-propionylamino)-5-(3′-chloro-biphenyl-4-yl)-2-methyl-pentanoic acid ethyl ester. MS m/z 446.3 (M+H), 444.3 (M−H). LC/MS (Condition A): 1.52 min. 1H NMR (400 MHz, DMSO-d6): 1.04-1.05 (d, J=7.07 Hz, 3H), 1.09-1.13 (t, J=7.07 Hz, 3H), 1.34-1.42 (m, 1H), 1.72-1.79 (m, 1H), 2.24-2.29 (m, 2H), 2.36-2.40 (m, 2H), 2.64-2.74 (m, 2H), 3.33 (s, 1H), 3.86-3.93 (m, 1H), 3.95-4.01 (q, J=7.33 Hz, 14.40 Hz, 2H), 7.25-7.27 (m, 2H), 7.39-7.41 (m, 1H), 7.46-7.50 (t, J=7.58 Hz, 1H), 7.61-7.64 (m, 3H), 7.70 (t, J=1.77 Hz, 1H), 7.75-7.77 (d, J=8.59 Hz, 1H), 12.08 (br s, 2H).

1. customSolvent was removed under reduced pressure
2. customthe residue was purified by preparatory HPLC (DAICEL CHIRALCEL OD-H 21×250 mm column, 18 ml/min, 90% heptane 10% EtOH+0.1% TFA)
3. customcollected a peak at 3.9 minutes