反应详情

A mixture of methyl (2S)-2-amino-3-(4-biphenylyl)-propanoate hydrochloride (415 mg, 1142 mmol),3,4-diisopropoxy-3-cyclobutene-1,2-dione (281 mg, 1.42 mmol), DIPEA (247 μl, 1.42 mmol) and MeOH (10 ml) was stirred at room temperature overnight. The solvent was removed in vacuo and the residue purified by column chromatography (SiO2; DCM/MeOH, 98:2) to give the title compound (358 mg). δH (DMSO-d6, 390K) 8.50 (1H, d, J 8.0 Hz), 7.63-7.56 (4H, m), 7.47-7.42 (2H, m), 7.36-7.32 (3H, m), 5.24-5.18 (1H, m), 4.80-4.75 (1H, m), 3.74 (3H, s), 3.31 (1H, dd, J 14.2, 5.2 Hz), 3.13 (1H, dd, J, 14.2, 9.4 Hz), 1.38 (3H, d, J 6.0 Hz), 1.37 (3H, d, J 6.1 Hz); m/z (ES+, 70 V) 394 (MH+).

1. customThe solvent was removed in vacuo
2. customthe residue purified by column chromatography (SiO2; DCM/MeOH, 98:2)