反应详情

温度

100 °C

The mixture of 4-bromo-thiophene-2-carbaldehyde (10 g, 0.052 mol), malonic acid (6.5 g, 0.063 mol) and piperidine (0.5 ml) in pyridine (40 ml) was stirred for 14 hours at 100° C., which was cooled down to room temperature and poured into water, and resultant mixture was acidified with concentrated HCl. The generated precipitate was collected by filtration, which was suspended with EtOH (50 ml) and water (100 ml). The precipitate was collected by filtration and dried under the reduced pressure to give 3-(4-bromo-thiophen-2-yl)-acrylic acid (14 g). 1H NMR (400 MHz, DMSO-d6) ppm 7.79 (s, 1H), 7.67 (d, J=15.9 Hz, 1H), 7.56 (s, 1H), 6.26 (d, J=15.9 Hz, 1H).

1. temperaturewhich was cooled down to room temperature
2. filtrationThe generated precipitate was collected by filtration, which
3. filtrationThe precipitate was collected by filtration
4. customdried under the reduced pressure