反应详情

2.5 M n-butyllithium (1.75 mL, 4.37 mmol) in hexane was slowly added to 6-[(R/S)-(2,2-dimethyl-1,3-dioxolan-4-yl)methyloxy]benzothiophene ((R/S)-25, 1.05 g, 3.97 mmol) obtained in step 1 dissolved in anhydrous tetrahydrofuran (150 mL) at −78° C. under nitrogen atmosphere. 15 Minutes later, the resulting mixture was agitated at room temperature for 1 hour. After cooling again to −78° C., triisopropyl borate ((i-PrO)3B; 1.10 mL, 4.77 mmol) was slowly added. After slowly heating to room temperature and agitating for 3 hours, water was added to quench the reaction. After extracting the organic compound with ethyl acetate and drying with sodium sulfate, column chromatography yielded the target compound 6-[(R/S)-(2,2-dimethyl-1,3-dioxolan-4-yl)methyloxy]benzothiophene-2-boronic acid ((R/S)-26, 880 mg, 72%).

1. customobtained in step 1
2. temperatureAfter cooling again to −78° C.
3. temperatureAfter slowly heating to room temperature
4. stirringagitating for 3 hours
5. customto quench
6. customthe reaction
7. extractionAfter extracting the organic compound with ethyl acetate
8. dry with materialdrying with sodium sulfate, column chromatography