反应详情

To a solution of 15 g of diisopropylamine in 75 ml of dry tetrahydrofuran was dropwise added 100 ml of n-butyl lithium (15 w/w, n-hexane solution) at -5° to 0° C. After stirring at the same temperature for 30 minutes, 6.7 g of isobutyric acid was added dropwise to the mixture. After stirring was continued at the same temperature for 1 hour, a solution of 20 g of p-(3-bromopropoxy)phenyl benzyl ether in 60 ml of dry tetrahydrofuran was added dropwise to the solution. Thirty minutes after, the mixture was stirred at room temperature for 16 hours. The mixture was cooled and 250 ml of water was added thereto. After the aqueous layer was washed with ether, the aqueous layer was acidified with 6N hydrochloric acid and extracted twice with 70 ml of methylene chloride. The extract was washed with an aqueous saturated sodium chloride solution and then dried over anhydrous sodium sulfate. After drying, the solvent was removed by distillation under reduced pressure and the residue was recrystallized from ethyl acetate to give the desired product, 5-(p-benzyloxyphenoxy)-2,2-dimethylpentanoic acid.

1. customat -5° to 0° C
2. stirringAfter stirring
3. waitwas continued at the same temperature for 1 hour
4. stirringThirty minutes after, the mixture was stirred at room temperature for 16 hours
5. temperatureThe mixture was cooled
6. washAfter the aqueous layer was washed with ether
7. extractionextracted twice with 70 ml of methylene chloride
8. washThe extract was washed with an aqueous saturated sodium chloride solution
9. dry with materialdried over anhydrous sodium sulfate
10. customAfter drying
11. customthe solvent was removed by distillation under reduced pressure
12. customthe residue was recrystallized from ethyl acetate