反应详情

温度

50 °C

3-Benzyl-7-bromo-5-methyl-benzofuran (3.93 g, 13.05 mmol) was mixed with 10 ml DMF. Phosphorus oxychloride (1.8 ml, 19.3 mmol) was added and the reaction mixture was heated to 50° C. for 16 hours. Additional phosphorus oxychloride (3.6 ml, 38.6 mmol) was added and the reaction mixture was heated to 90° C. for an hour, then to 100° C. for five hours. The mixture was cooled to room temperature, poured onto ice and aqueous sodium hydroxide was added until the mixture reached pH=3. The mixture was extracted with ethyl acetate, dried over magnesium sulfate, filtered, and absorbed onto 20 gm silica gel. The silica gel was layered over 100 gm silica gel in a fritted funnel and eluted with five portions of 400 ml hexanes (to give 0.33 g recovered starting material) and two portions of 400 ml of 10/90 ethyl acetate/hexane to give 3-benzyl-7-bromo-5-methyl-benzofuran-2-carbaldehyde (2.61 g, 61% yield). MS: (M+H)+ 330.

1. temperaturethe reaction mixture was heated to 90° C. for an hour
2. temperatureThe mixture was cooled to room temperature
3. additionwas added until the mixture
4. extractionThe mixture was extracted with ethyl acetate
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. customabsorbed onto 20 gm silica gel
8. customThe silica gel was layered over 100 gm silica gel in a fritted funnel
9. washeluted with five portions of 400 ml hexanes (to give 0.33 g recovered starting material) and two portions of 400 ml of 10/90 ethyl acetate/hexane