反应详情

A mixture of benzofuran-5-carbaldehyde (150 mg, 1.03 mmol), ethylene glycol (230 ul, 4 eq), trimethyl orthoformate (123 ul, 1.1 eq) and tetrabutylammonium tribromide (49 mg, 0.1 eq) was stirred at room temperature for one night. Some starting material could be detected by TLC. However, the reaction mixture was poured into saturated NaHCO3 solution and the product was extracted with ethyl acetate. Combined organic layers were dried over anhydrous sodium sulfate, filtrated and concentrated to give a crude product, which was purified by flash chromatography using cyclohexane/ethyl acetate 20:0.75 as solvents. The title compounds was obtained in 36% yield (70 mg).

1. extractionthe product was extracted with ethyl acetate
2. dry with materialCombined organic layers were dried over anhydrous sodium sulfate
3. filtrationfiltrated
4. concentrationconcentrated
5. customto give a crude product, which
6. customwas purified by flash chromatography