Boron tribromide → HCID 53407597, compound

Temperature

-74 °C

2-Chloro-3-fluoro-6-methoxybenzaldehyde (46.0 g, 245 mmol) was added in a three neck flask equipped with a nitrogen inlet, a thermometer and an addition funnel. DCM (800 mL) was added and cooled to −70 to −78° C. using an acetone/dry ice bath. Boron tribromide (25.4 mL, 269 mmol) was diluted in 200 mL of dichloromethane and added to the reaction mixture slowly over a period of 1 h. The reaction mixture was allowed to warm to room temperature and stirred for 16 h. Then the reaction mixture was cooled to 0° C. in an ice bath and quenched by adding methanol (150 mL) over a period of 30 minutes and stirred at room temperature for 20 min. The solvents were removed, and the residue was diluted with dichloromethane and washed with aq. sodium bicarbonate solution followed by water. The organic layer was dried over sodium sulfate, filtered and concentrated to give crude product. It was purified by column chromatography on silica gel eluting with 2→3% methanol in dichloromethane, giving 34 g (80% yield) of the title compound. 1HNMR (300 MHz, CDCl3): δ=11.68 (s, 1H), 10.39 (s, 1H), 7.26-7.35 (m, 1H), 6.86-6.90 (m, 1H).

1. customequipped with a nitrogen inlet
2. additionadded to the reaction mixture slowly over a period of 1 h
3. temperatureto warm to room temperature
4. temperatureThen the reaction mixture was cooled to 0° C. in an ice bath
5. customquenched
6. additionby adding methanol (150 mL) over a period of 30 minutes
7. stirringstirred at room temperature for 20 min
8. customThe solvents were removed
9. additionthe residue was diluted with dichloromethane
10. washwashed with aq. sodium bicarbonate solution
11. dry with materialThe organic layer was dried over sodium sulfate
12. filtrationfiltered
13. concentrationconcentrated
14. customto give crude product
15. customIt was purified by column chromatography on silica gel eluting with 2→3% methanol in dichloromethane

ORD record

ord-e0dfbced29e84ec0ab81cdf0d86acac1

Source dataset

uspto-grants-2013_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08445510B2