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 5.7 minutes, to give 25 mg (2S,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.

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 5.7 minutes