反应详情

温度

80 °C

58.4 g (0.22 mol) of 6-bromo-5,8-dimethyl-4-thiochromanone were dissolved in 380 ml of trimethyl orthoformate, admixed with 555 g (8.9 mol) of ethanediol and 0.2 g of p-toluenesulfonic acid monohydrate and stirred at 80° C. overnight. The mixture was subsequently allowed to cool, diluted with 500 ml of diethyl ether and washed with a 1:1 mixture of 1 M aqueous sodium hydroxide solution and sat. NaCl solution (2×500 ml) and subsequently with sat. NaCl solution (300 ml). The organic phase was dried over MgSO4 and concentrated using a rotary evaporator. The residue was taken up in 50 ml of heptaneldiethyl ether (9:1) and stored in a cold place. The crystals which had precipitated overnight were filtered off with suction, washed with cold heptane and dried.

1. temperatureto cool
2. washwashed with a 1:1 mixture of 1 M aqueous sodium hydroxide solution and sat. NaCl solution (2×500 ml) and subsequently with sat. NaCl solution (300 ml)
3. dry with materialThe organic phase was dried over MgSO4
4. concentrationconcentrated
5. customa rotary evaporator
6. customThe crystals which had precipitated overnight
7. filtrationwere filtered off with suction
8. washwashed with cold heptane
9. customdried