反应详情

A mixture of 5.0 g (0.03 mol) of 3,5-dihydroxybenzoic acid methyl ester, 9.9 g (0.03 mol) of 1-bromooctadecane and 4.1 g (0.03 mol) of potassium carbonate in 100 ml of acetone and 5 ml of DMF was stirred at reflux for 24 hours. The solvents were removed at reduced pressure and the residue was stirred with ethyl acetate and filtered to remove inorganic salts. The filtrate was concentrated to dryness and the residue was stirred with 500 ml of methylene chloride and filtered to remove the residual 3,5-dihydroxybenzoic acid methyl ester. The filtrate was concentrated and purified by chromatography on 300 g of silica gel using 5% ethyl acetate-toluene to give 4.07 g (33% yield, mp 93°-94°) of 3-hydroxy-5-(octadecyloxy) benzoic acid methyl ester.

1. temperatureat reflux for 24 hours
2. customThe solvents were removed at reduced pressure
3. stirringthe residue was stirred with ethyl acetate
4. filtrationfiltered
5. customto remove inorganic salts
6. concentrationThe filtrate was concentrated to dryness
7. stirringthe residue was stirred with 500 ml of methylene chloride
8. filtrationfiltered
9. customto remove the residual 3,5-dihydroxybenzoic acid methyl ester
10. concentrationThe filtrate was concentrated
11. custompurified by chromatography on 300 g of silica gel using 5% ethyl acetate-toluene