Triethyl borate → 2,4,6-Trimethylbenzeneboronic acid

Magnesium (60.27 mmol) and tetrahydrofuran (30 mL) were put in a three-necked round bottom flask and stirred. To the solution, bromomesitylene (13.07 mmol) was added, and the reaction mixture was heated. After that, bromomesitylene (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. Then, the mixture was cooled to −78° C. (EtO)3B (111.66 mmol) was added dropwise over 15 minutes. After that, 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 and stirring for additional 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. The filtrate was concentrated to give a solid, which was recrystallized in benzene to give GA33 (26.10 mmol, yield: 58%).

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
9. stirringstirring for additional 2 hours
10. extractionThe reaction mixture was extracted with diethyl ether three times
11. washThe combined extracts was washed with brine
12. dry with materialdried over anhydrous sodium sulfate
13. filtrationAfter the drying, the extract was filtered
14. concentrationThe filtrate was concentrated
15. customto give a solid, which
16. customwas recrystallized in benzene
17. customto give GA33 (26.10 mmol, yield: 58%)

ORD record

ord-d6c2e301df734457969b65593e210ae7

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07517828B2