反应详情

To a cooled (0° C.) solution of 6-hydroxy-benzofuran-3-carboxylic acid ethyl ester (5.85 g, 28.4 mmol) in THF (250 mL) was added DIBALH as a solution in THF (100 mL, 100 mmol) and the reaction mixture was allowed to warm (rt, 1 h). The reaction was cooled (−78° C.) and treated dropwise with Rochelles salt (120 mL). The resulting mixture was stirred (rt, o/n). The layers were separated and the aqueous layer was extracted with DCM (2×200 mL) and EtOAc (2×200 mL). The organic layers were combined, dried, filtered and concentrated in vacuo to provide the title compound as a white solid (4.72 g, 100%). 1H NMR (500 MHz, CD3OD): 7.53 (s, 1H), 7.45 (d, J=8.4, 1H), 6.85 (d, J=2.1, 1H), 6.76 (dd, J=8.4, 2.1, 1H), 4.70 (s, 2H).

1. temperatureThe reaction was cooled (−78° C.)
2. customThe layers were separated
3. extractionthe aqueous layer was extracted with DCM (2×200 mL) and EtOAc (2×200 mL)
4. customdried
5. filtrationfiltered
6. concentrationconcentrated in vacuo