反应详情

15.0 g (59.0 mmol) diethyl-2,5-dihydroxyterephthalate, 20.0 ml (142 mmol) 1-bromohexane, 28.0 g (203 mmol) K2CO3 and 200 mg NaI in 100 ml acetone are heated under reflux for 66 hours. The initially yellow suspension becomes largely decolorized. The solvent is then distilled off and the residue is taken up in 400 ml ethyl acetate and 200 ml water. After removing the aqueous phase, the organic phase is washed three times with 80 ml 1 N NaOH and three times with 100 ml water and then dried over Na2SO4. After distilling off the ethyl acetate, the residue is taken up in petroleum ether. At -30° C., colourless crystals form which are recrystallized again from petroleum ether.

1. temperatureunder reflux for 66 hours
2. distillationThe solvent is then distilled off
3. customAfter removing the aqueous phase
4. washthe organic phase is washed three times with 80 ml 1 N NaOH and three times with 100 ml water
5. dry with materialdried over Na2SO4
6. distillationAfter distilling off the ethyl acetate
7. customAt -30° C., colourless crystals form which are recrystallized again from petroleum ether