反应详情

温度

90 °C

4-Bromo benzamide (28.0 g, 0.140 mol) was suspended in 1,1-dimethoxy-N,N-dimethylmethanamine (50 mL, 420 mmol) and the solution was stirred and heated to 90° C. for 2 hours. The solution was then cooled to ambient temperature and diethyl ether (150 mL) was added. The solution was cooled to 0° C. overnight and filtered to give (E)-4-bromo-N-((dimethylamino)methylene)benzamide as a colorless solid (25.6 g). This material was then dissolved in acetic acid (50 mL) and hydrazine (3.50 g, 110 mmol) was added slowly (exotherm) to the stirred solution, which solidified. The mixture was heated to 90° C. and a stir bar was added. The solid slowly dissolved over 8 hours and was then cooled to ambient temperature and the solution was diluted with water (35 mL). The resulting white solid was filtered and dried in vacuo to furnish the title compound as a colorless solid (19.8 g, 88%): 1H NMR (400 MHz, DMSO-d6) δ 13.91 (s, 1H), 8.51 (s, 1H), 8.01-7.93 (m, 2H), 7.73-7.67 (m, 2H; ESIMS m/z 224, 226 ([M+H]+).

1. temperatureThe solution was then cooled to ambient temperature
2. temperatureThe solution was cooled to 0° C. overnight
3. filtrationfiltered