反应详情

To the ice-cold 3 mL (39.2 mmol) of dimethylformamide (DMF) was added phosphorus oxychloride (0.67 mL, 7.18 mmol) drop wise and the resultant mixture was stirred for 30 minutes. A solution of 1 g (6.53 mmol) of 4-methyl-1H-pyrrole-2-carboxylic acid ethyl ester in 3 mL of DMF was added to the reaction. After 1 h, the reaction was warmed to room temperature for another 2.5 h. The reaction mixture was diluted with water (100 mL) and basified to pH=11 with 1N sodium hydroxide solution. The precipitate was removed by filtration, rinsing with water and dried to afford 0.8 g (68%) of 5-formyl-4-methyl-1H-pyrrole-2-carboxylic acid ethyl ester as a white solid.

1. customThe precipitate was removed by filtration
2. washrinsing with water
3. customdried