反应详情

温度

80 °C

Into a 250-mL round-bottom flask, was placed 5-formyl-2,4-dimethylbenzoic acid (compound 83.1, 2.00 g, 11.2 mmol) and methanol (50 mL). Concentrated sulfuric acid (2 mL) was carefully added drop-wise and the resulting solution was stirred for 2 h at 80° C., then cooled and the volatiles were removed under reduced pressure. The pH of the residue was adjusted to 9 with sodium bicarbonate (sat.), then the aqueous phase was extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with brine (2×20 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure to yield 2.0 g (crude) of the title compound as yellow oil. The crude product was used in next step without further purification.

1. customInto a 250-mL round-bottom flask, was placed
2. temperaturecooled
3. customthe volatiles were removed under reduced pressure
4. extractionthe aqueous phase was extracted with ethyl acetate (3×50 mL)
5. washThe combined organic layers were washed with brine (2×20 mL)
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure