反应详情

To a stirred solution of tert-butyl 4-fluoro-3-(methylaminomethyl)benzoate (2.42 g, 10.1 mmole) in DMF (75 mL) was added N-(benzyloxycarbonyl)-D-alanine (2.45 g, 11 mmole) and HOBt.H2O (1.5 g, 11 mmole), followed by DCC (2.4 g, 11.6 mmole). The reaction was stirred for 16 h then was concentrated to dryness. Purification by flash chromatography on silica gel (30% EtOAc/hexanes) gave the title compound (3.29 g, 73%) as a clear oil: 1H NMR (300 MHz, CDCl3) mixture of amide rotamers δ 7.90-7.95 (m, 1H), 7.81 (dd, 1H), 7.31-7.32 (m, 5H), 7.08 (t, 1H), 5.72 & 5.83 (2 d, J=7.8 Hz, 1H), 5.11 (s, 2H), 4.89 (d, J=15.3 Hz, 1H), 4.72-4.77 (m, 1H), 4.47 (d, J=15.3 Hz, 1H), 2.92 & 3.05 (2s, 3H), 1.56 (s, 9H), 1.37 & 1.40(2 d, J=6.8 Hz, 3H).

1. concentrationthen was concentrated to dryness
2. customPurification by flash chromatography on silica gel (30% EtOAc/hexanes)