反応 #1262374

反応方程式

epibromohydrin

epibromohydrin

potassium carbonate

diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate

propylene

→

diethyl 2,3-dihydro-2-(hydroxymethyl)thieno[3,4-b][1,4]dioxine-5,7-dicarboxylate

収率 55.0%

溶媒

hexane

water

ethyl acetate

ethanol

反応条件

後処理

1. 1
   温度After heating
2. 2
   温度to reflux for 1 hour
3. 3
   温度the reaction heated
4. 4
   温度to reflux overnight
5. 5
   濃縮was concentrated by evaporation
6. 6
   workup.ADDITIONpoured into 500 ml water
7. 7
   抽出extracted with methylene chloride until the
8. 8
   洗浄organic wash no longer indicated product
9. 9
   洗浄The organic fractions were washed with saturated brine
10. 10
    乾燥then dried with magnesium sulfate
11. 11
    その他The solvent was removed under reduced pressure
12. 12
    その他to give a yellow solid
13. 13
    その他to give

実験手順

7.7 mL (0.0902 mol) of epibromohydrin and 1.92 g (0.0139 mol) of potassium carbonate were dissolved in 100 mL water and added to a refluxing mixture of 16.11 g (0.0694 mol) diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate in 350 mL ethanol. After heating to reflux for 1 hour, an additional 5.3 mL (0.0624 mol) epibromohydrin was added and the reaction heated to reflux overnight. Upon cooling to room temperature the reaction was concentrated by evaporation and then poured into 500 ml water. The mixture was acidified and then extracted with methylene chloride until the organic wash no longer indicated product was present. The organic fractions were washed with saturated brine then dried with magnesium sulfate. The solvent was removed under reduced pressure to give a yellow solid. Column chromatography was performed using 60% ethyl acetate in hexane to give a 70:30 mixture of the product and propylene isomer in 55% yield as a white solid. Structure and purity were confirmed by 1H/13C NMR and LC-MS.

出典