反应详情

温度

-65 °C

1-Fluoro-2,3-methylenedioxybenzene (5.0 g, 35.7 mmol) was dissolved in THF (70 mL) and the solution was cooled to −65° C. in a dry ice acetone bath. n-Butyl lithium (2.5 g, 15.7 mL, 39.3 mmol) was added to the solution via syringe with stirring. The reaction was allowed to warm to 35° C. over 1 hour, then cooled to −65° C. and treated with trimethylborate (4.1 g, 39.3 mmol) via syringe. The reaction was allowed to warm slowly to room temperature, quenched with 1N HCl (50 mL), stirred for 15 minutes, and then extracted with ether. The organic phase was then extracted with 1N sodium hydroxide and this aqueous extract was then acidified with 1N hydrochloric acid. The acidic aqueous solution was then extracted with two portions of ether and these combined ether extracts were dried and concentrated to an oily solid that was triturated with methylene chloride. The resulting solid was collected by filtration, washed with methylene chloride, and dried to give 1-fluoro-2,3-methylenedioxyphenylboronic acid (1.4 g, 7.6 mmol) as a tan solid: 1H NMR (DMSO-d6): δ 8.05 (br s, 2H), 7.08 (dd, 1H, J=7.8, 5.1 Hz), 6.76 (d, 1H, J=7.8 Hz), 6.08 (s, 2H).

1. temperatureto warm to 35° C. over 1 hour
2. temperaturecooled to −65° C.
3. temperatureto warm slowly to room temperature
4. customquenched with 1N HCl (50 mL)
5. stirringstirred for 15 minutes
6. extractionextracted with ether
7. extractionThe organic phase was then extracted with 1N sodium hydroxide
8. extractionthis aqueous extract
9. extractionThe acidic aqueous solution was then extracted with two portions of ether
10. dry with materialthese combined ether extracts were dried
11. concentrationconcentrated to an oily solid
12. customthat was triturated with methylene chloride
13. filtrationThe resulting solid was collected by filtration
14. washwashed with methylene chloride
15. customdried