反应详情

温度

125 °C

To a round bottom flask was added diethyl 1-amino-1H-pyrrole-2,4-dicarboxylate (40 g, 177 mmol), diethoxypropionitrile (53 mL) and p-TSA (10 g, 0.052 mmol). The reaction was heated at 125° C. for 3 hours and the EtOH was removed. The reaction was cooled to room temperature before DBU (30 g, 340 mmol) was added. The reaction was then heated at 80° C. for 2 hours. The reaction was cooled to room temperature and diluted with CH2Cl2. The mixture was washed with 5% citric acid solution (2×), water and brine solution. The organic layer was concentrated and the residue was purified by flash silica gel column chromatography (10% MeOH in CHCl3) to yield 20 g (50%) of the title compound as a brown oil. LCMS (condition A): m/z=230.2 −ve. 1H NMR (400 MHz, CDCl3) δ ppm: 9.53 (1H, br s), 8.32 (1H, s), 7.75 (1H, s), 6.75 (1H, s), 4.25 (2H, q), 1.28 (3H, t).

1. customthe EtOH was removed
2. additionwas added
3. temperatureThe reaction was then heated at 80° C. for 2 hours
4. temperatureThe reaction was cooled to room temperature
5. washThe mixture was washed with 5% citric acid solution (2×), water and brine solution
6. concentrationThe organic layer was concentrated
7. customthe residue was purified by flash silica gel column chromatography (10% MeOH in CHCl3)