Boron tribromide → HCID 117699342, compound

2-(4-trifluoromethylphenyl)-3-methoxy-5,7-dihydroxy-4H-chromen-4-one (10 g, 28.3 mmol) was dissolved into 150 mL dichloromethane in a 250 ml three-necked flask. Boron tribromide (21.2 g, 84.9 mmol) was slowly dropped into the solution at 0° C. After that, the solution was heated to room temperature and reacted for 4 hours, and quenched with 80 mL ice water for terminating the chemical reaction. The solution was extracted with 500 mL ethyl acetate for 3 times. The extracts were combined, washed with saturated sodium chloride aqueous solution once and dried with anhydrous sodium sulfate. After filtration, crude product was mixed with 20 mL ethyl acetate/petroleum (1:10) and stirred, and target yellow compound was obtained after filtering and drying. (7 g, yield 70%).

1. customreacted for 4 hours
2. customquenched with 80 mL ice water
3. customfor terminating
4. customthe chemical reaction
5. extractionThe solution was extracted with 500 mL ethyl acetate for 3 times
6. washwashed with saturated sodium chloride aqueous solution once
7. dry with materialdried with anhydrous sodium sulfate
8. filtrationAfter filtration, crude product
9. additionwas mixed with 20 mL ethyl acetate/petroleum (1:10)
10. customtarget yellow compound was obtained
11. filtrationafter filtering
12. customdrying

ORD record

ord-23f497682f2b4fdc81826e494baa7b01

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09221781B2