反应详情

To 4.5 g of 2-ethyl-2-methyl-5-{4-(methylsufonyl)phenyl}-3(2H)-furanone dissolved in 100 ml carbon tetrachloride, were added acetic acid (3 ml) and bromine (1 ml). The reaction solution was stirred for 1 hour at room temperature. Then the reaction was quenched by adding saturated aqueous sodium thiosulfate solution until the characteristic color of bromine disappeared. The reaction solution was extracted with dichloromethane (30 ml×3) and the organic layer was concentrated in vacuo. The resulting residue was purified by column chromatographic separation (hexane/ethylacetate=1:1) to give 4 g of 4-bromo-2-ethyl-2-methy-5-{4-(methylsulfonyl)phenyl}-3(2H)-furanone. NMR: δ0.91 (t, J=7.2 Hz, 3H), 1.52 (s, 3H), 1.95 (qd, J=7.2, 3.0 Hz, 2H), 3.11 (s, 3H), 8.11 (d, J=8.7 Hz, 2H), 8.41 (d, J=8.7 Hz, 2H). IR (cm−1): 2928, 1703, 1583, 1316, 1160, 552.

1. customThen the reaction was quenched
2. additionby adding saturated aqueous sodium thiosulfate solution until the characteristic color of bromine
3. extractionThe reaction solution was extracted with dichloromethane (30 ml×3)
4. concentrationthe organic layer was concentrated in vacuo
5. customThe resulting residue was purified by column chromatographic separation (hexane/ethylacetate=1:1)