Triethyl borate → (Naphthalen-2-yl)boronic acid

Magnesium (60.27 mmol) and tetrahydrofuran (30 mL) were put in a three-necked round bottom flask and stirred. To the solution, 2-bromonaphthalene (13.07 mmol) was added, and the reaction mixture was heated. After that, 2-bromonaphthalene (32.02 mmol) dissolved in tetrahydrofuran (30 mL) was added dropwise to the solution. The reaction mixture was heated and refluxed for 4.5 hours. After that, the mixture was cooled to −78° C. (EtO)3B (111.66 mmol) was added dropwise over 15 minutes. Then, the mixture was warmed to room temperature and stirred for additional 5 hours. Then, the mixture was cooled to 0° C. The reaction was quenched by the addition of 1 M hydrochloric acid stirring for 2 hours. The reaction mixture was extracted with diethyl ether three times. The combined extracts was washed with brine and dried over anhydrous sodium sulfate. After the drying, the extract was filtered. Then the filtrate was concentrated. The obtained solid was recrystallized in benzene to give GA40 (9 mmol, yield: 77%).

1. temperaturethe reaction mixture was heated
2. additionwas added dropwise to the solution
3. temperatureThe reaction mixture was heated
4. temperaturerefluxed for 4.5 hours
5. additionwas added dropwise over 15 minutes
6. stirringstirred for additional 5 hours
7. temperatureThen, the mixture was cooled to 0° C
8. customThe reaction was quenched by the addition of 1 M hydrochloric acid stirring for 2 hours
9. extractionThe reaction mixture was extracted with diethyl ether three times
10. washThe combined extracts was washed with brine
11. dry with materialdried over anhydrous sodium sulfate
12. filtrationAfter the drying, the extract was filtered
13. concentrationThen the filtrate was concentrated
14. customThe obtained solid was recrystallized in benzene

ORD record

ord-f6184b7ef8b9462aaca192a3082b259b

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07517828B2