反应详情

温度

100 °C

To a solution of 0.8 g (4.4 mmol) of 5-formyl-4-methyl-1H-pyrrole-2-carboxylic acid ethyl ester in 35 mL of water and 15 mL of ethanol was added 0.5 g (8.9 mmol) of potassium hydroxide. The reaction mixture was heated to 100 ° C. for 1 hour, cooled to room temperature, and evaporated ethanol. The water layer was acidified to pH=3 using 2N hydrogen chloride solution. The precipitate was filtered and washed with water to afford 0.67 g (68%) of 5-formyl-4-methyl-1H-pyrrole-2-carboxylic acid as a tan solid. 1H NMR (360 MHz, DMSO-d6) δ 12.92 (br s, 1H, CO2H), 12.48 (br s, 1H, NH), 9.76 (s, 1H, CHO-5), 6.63 (s, 1H), 2.28 (s, 3H, CH3). MS m/z 152 [M−1].

1. temperaturecooled to room temperature
2. customevaporated ethanol
3. filtrationThe precipitate was filtered
4. washwashed with water