反应详情

Phosphorus oxychloride (26.2 ml, 0.29 mol) was added dropwise to N,N-dimethylformamide (17 ml, 0.22 mol) under ice cooling; subsequently, a solution of 5-benzyloxy-4-tert-butylbenzofuran (40 g, 0.14 mol) in N,N-dimethylformamide (10 ml) was added dropwise. The mixture was stirred first at room temperature for 20 min, then under heating at 80° C. for 2 h. After cooling, the reaction mixture was poured into water and extracted with ethyl acetate. The extracted layer was washed with a saturated aqueous solution of sodium hydrogen carbonate and water, dried over anhydrous magnesium sulfate and concentrated. The concentrate was purified by silica gel chromatography (10% ethyl acetate in n-hexane) to afford 5-benzyloxy-4- tert-butyl-2-formylbenzofuran [16.2 g (yield, 36%)].

1. temperatureunder heating at 80° C. for 2 h
2. temperatureAfter cooling
3. extractionextracted with ethyl acetate
4. washThe extracted layer was washed with a saturated aqueous solution of sodium hydrogen carbonate and water
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated
7. customThe concentrate was purified by silica gel chromatography (10% ethyl acetate in n-hexane)