反应详情

温度

70 °C

N′-Hydroxy-4-[(2-methoxyethyl)amino]-N-[3-(trifluoromethyl)phenyl]-1,2,5-oxadiazole-3-carboximidamide (1.4 g, 3.80 mmol) and 1,1′-carbonyldiimidazole (1.16 g, 7.16 mmol) were dissolved in ethyl acetate (20 mL). The reaction mixture was heated at 70° C. for 40 minutes. Additional 1,1′-carbonyldiimidazole (0.26 g, 1.16 mmol) was added. After stirring at 70° C. for another 50 minutes, the reaction was allowed to cool to room temperature. Ethyl acetate (20 mL) was added and the crude reaction was washed with 1 N HCl in water (2×20 mL). Brine was added to aid in the separation of the first wash. The organic layer was dried over sodium sulfate and concentrated in vacuo. Purification by flash chromatography on silica gel with an eluent of ethyl acetate in hexanes gave the desired product (1.3 g, 90%). LCMS calculated for C14H13F3N5O4 (M+H)+: m/z=372.0. 1H NMR (400 MHz, DMSO-d6): δ 8.07 (s, 1H), 7.92 (m, 2H), 7.79 (t, J=8.1 Hz, 1H), 6.42 (t, J=6.0 Hz, 1H), 3.47 (t, J=5.8 Hz, 2H), 3.38 (q, J=5.0 Hz, 2H), 3.24 (s, 3H).

1. temperatureto cool to room temperature
2. customthe crude reaction
3. washwas washed with 1 N HCl in water (2×20 mL)
4. additionBrine was added to aid in the separation of the first wash
5. dry with materialThe organic layer was dried over sodium sulfate
6. concentrationconcentrated in vacuo
7. customPurification by flash chromatography on silica gel with an eluent of ethyl acetate in hexanes