反应详情

A mixture of 50.0 g (0.297 mol) of methyl 3,5-dihydroxybenzoate, 99.2 g (0.297 mol) of 1-bromooctadecane and 41 g (0.297 mol) of potassium carbonate in 100 ml of acetone and 50 ml of DMF was stirred at reflux under argon for 24 hours. The solvents were removed at reduced pressure and the residue was heated with methylene chloride and filtered hot. The filtrate was concentrated at reduced pressure to a solid which was recrystallized from methylene chloride-methanol to give the 3,5-dialkylated product. The filtrate was concentrated to dryness and the residue was recrystallized from methylene chloride-methanol to give more of the dialkylated product. The filtrate was concentrated to dryness and recrystallized from ether-hexane to give 40.2 g (32% yield, mp 95°-97°) of 3-hydroxy-5-(octadecyloxy)benzoic acid methyl ester.

1. temperatureat reflux under argon for 24 hours
2. customThe solvents were removed at reduced pressure
3. temperaturethe residue was heated with methylene chloride
4. filtrationfiltered hot
5. concentrationThe filtrate was concentrated at reduced pressure to a solid which
6. customwas recrystallized from methylene chloride-methanol
7. customto give the 3,5-dialkylated product
8. concentrationThe filtrate was concentrated to dryness
9. customthe residue was recrystallized from methylene chloride-methanol
10. customto give more of the dialkylated product
11. concentrationThe filtrate was concentrated to dryness
12. customrecrystallized from ether-hexane