反应详情

A mixture of 50.0 g of 3-hydroxy-4-methoxybenzoic acid in 500 ml of absolute methyl alcohol containing 2.5 ml of concentrated sulfuric acid, is heated at reflux temperature for 6 hours. The reaction is concentrated in vacuo, 250 ml of ice water is added and the residue is extracted with diethyl ether. The organic layers are washed with saturated sodium bicarbonate and saturated sodium chloride, dried and concentrated in vacuo. The residue is dissolved in diethyl ether, passed through a pad of silica gel and concentrated in vacuo. The solid is recrystallized from diethyl ether/hexane to give 33 g of the desired product as white crystals.

1. temperatureis heated
2. temperatureat reflux temperature for 6 hours
3. concentrationThe reaction is concentrated in vacuo, 250 ml of ice water
4. additionis added
5. extractionthe residue is extracted with diethyl ether
6. washThe organic layers are washed with saturated sodium bicarbonate and saturated sodium chloride
7. customdried
8. concentrationconcentrated in vacuo
9. dissolutionThe residue is dissolved in diethyl ether
10. concentrationconcentrated in vacuo
11. customThe solid is recrystallized from diethyl ether/hexane