反应详情

A solution of 8-bromo-4-(trimethylsilyl)-3,4-dihydro-2H-chromene-4-carbonitrile (9.6 g, 29.45 mmol) in a mixture of conc. HCl/HOAc (50 mL/40 mL) was added SnCl2.H2O (26.57 g, 117.8 mmol) and the miture was refluxed for 48 hours. The reaction solution was concentrated and the residue was partitioned between water and EtOAc. The combined organic layers were washed with brine, dried over anhydrous Na2SO4 and concentrated to afford 8-bromo-3,4-dihydro-2H-chromene-4-carboxylic acid. 1H-NMR (300 MHz, CDCl3) δ ppm 7.15˜7.46 (m, 2H), 6.75˜6.92 (m, 1H), 4.24˜4.4 (m, 2H), 3.78˜3.84 (m, 1H), 2.1˜2.39 (m, 2H).

1. temperaturethe miture was refluxed for 48 hours
2. concentrationThe reaction solution was concentrated
3. customthe residue was partitioned between water and EtOAc
4. washThe combined organic layers were washed with brine
5. dry with materialdried over anhydrous Na2SO4
6. concentrationconcentrated