反应详情

A solution of 4-(biphenyl-4-yl)-3-(tert-butoxycarbonylamino)butanoic acid (250 mg, 0.703 mmol), tBuOH (0.135 ml, 1.407 mmol), EDCl (270 mg, 1.407 mmol) and 4-dimethylaminopyridine (86.0 mg, 0.704 mmol) in DCM (7 ml) is allowed to stir at room temperature under nitrogen for 62 hours. The reaction is quenched with water, and the organic layer is separated and concentrated. The residue is purified by flash column chromatography on silica gel to give tert-butyl 4-(biphenyl-4-yl)-3-(tert-butoxycarbonylamino)butanoate (110 mg); HPLC retention time=1.77 minutes (condition B); MS (ES+)=412.1 (m+1) 300.0 (m-tBux2+3; 100%); 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.41 (s, 9H) 1.47 (s, 9H) 2.36 (A of ABX, Jab=15.5 Hz, Jax=6.2 Hz, 1H) 2.44 (B of ABX, Jab=15.5 Hz, Jbx=5.6 Hz) 2.82-2.94 (m, 2H) 4.11-4.17 (m, 1H) 5.08-5.10 (m, 1H) 7.25-7.34 (m, 3H) 7.41-7.44 (m, 2H) 7.51-7.58 (m, 4H).

1. customThe reaction is quenched with water
2. customthe organic layer is separated
3. concentrationconcentrated
4. customThe residue is purified by flash column chromatography on silica gel