반응 #52140

반응 방정식

4-bromo-2,6-dimethoxy-phenol

NaOH

dimethyl sulfate

→

18

수율 79.0%

3,4,5-trimethoxybromobenzene

수율 79.0%

용매

H2O

반응 조건

후처리

1. 1
   온도The mixture was refluxed for 3 h
2. 2
   온도The mixture was refluxed for another 3 h
3. 3
   온도Upon cooling overnight
4. 4
   여과was filtered off
5. 5
   workup.DISSOLUTIONdissolved in 1.2 l of ether
6. 6
   여과The ether solution was filtered
7. 7
   기타to remove insoluble impurity
8. 8
   세척washed sequentially with 5% NaOH solution (200 ml), water (2×200 mL), and brine (200 mL)
9. 9
   건조The ether phase was dried over Na2SO4
10. 10
    기타to give a off-white solid, which
11. 11
    기타was recrystallized in hexane (300 ml)

실험 절차

A mixture of 74 g (0.32 mol) of 4-bromo-2,6-dimethoxy-phenol 17 and 32 g (0.8 mol) of NaOH in 850 ml of H2O was cooled to 10° C. and 45 ml (0.48 mmol) of dimethyl sulfate was added. The mixture was refluxed for 3 h and an equal amount of dimethyl sulfate (total 0.96 mol) was then added. The mixture was refluxed for another 3 h. Upon cooling overnight, the gray product solidified and was filtered off and dissolved in 1.2 l of ether. The ether solution was filtered to remove insoluble impurity and washed sequentially with 5% NaOH solution (200 ml), water (2×200 mL), and brine (200 mL). The ether phase was dried over Na2SO4 to give a off-white solid, which was recrystallized in hexane (300 ml) to give 62.3 g (79%) of 18.

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