反应详情

Add anhydrous hydrogen chloride gas (18.0 g) to anhydrous ethanol DB (210 g) by purging the solution. Add this hot solution (60° C.) to a solution of 2-[4-(4-chloro-butyryl)-phenyl]-2-methyl-propionic acid (31 g, 115.6 mmol) and reflux under a nitrogen atmosphere for 2.5 hours. Evaporate the solvent in vacuo, dissolve the residue in methylene chloride (150 mL) and wash with water (2×100 mL). Dry (MgSO4), filter through silica gel, washing the gel with methylene chloride (250 mL). Combine the organic washings and evaporate the solvent in vacuo to give the title compound as a colorless oil (33.3 g, 97%).

1. customby purging the solution
2. temperaturereflux under a nitrogen atmosphere for 2.5 hours
3. customEvaporate the solvent in vacuo
4. dissolutiondissolve the residue in methylene chloride (150 mL)
5. washwash with water (2×100 mL)
6. dry with materialDry (MgSO4)
7. filtrationfilter through silica gel
8. washwashing the gel with methylene chloride (250 mL)
9. customCombine the organic washings and evaporate the solvent in vacuo