反应详情

A solution of 4-chloro-N′-hydroxybenzimidamide (1.24 g, 7.27 mmol), (S)-2-(tert-butoxycarbonylamino)propanoic acid (1.38 g, 7.27 mmol, 1.0 equiv), and DCC (1.65 g, 8.00 mmol, 1.1 equiv) in 1,4-dioxane (73 mL) was heated at 100° C. for 18 hours. The reaction was then cooled to room temperature and concentrated in vacuo. Silica gel column chromatography (EtOAc/Heptane, 0 to 35%) provided (S)-tert-butyl 1-(3-(4-chlorophenyl)-1,2,4-oxadiazol-5-yl)ethylcarbamate (1.13 g, white solid) in 48% yield. 1H NMR (400 MHz, CDCl3) δ 8.03 (d, J=8.8 Hz, 2H), 7.47 (d, J=8.8 Hz, 2H), 5.18 (m, 1H), 1.64 (d, J=6.8 Hz, 3H), 1.47 (s, 9H).

1. concentrationconcentrated in vacuo