1,3-Dibromo-5,5-dimethylhydantoin → 6-(Bromomethyl)-2,3-dihydro-4H-chromen-4-one

A solution of 6-Methyl-2,3-dihydro-4H-chromen-4-one (7.2 g, 44 mmol), 5,5-Dimethyl-1,3-dibromohydantoin (7.7 g, 27 mmol), and Azobisisobutyronitrile (1.5 g, 9 mmol) in monochlorobenzene (140 mL) was stirred at 80° C. for 3 hours. The reaction solution was poured into ice water (100 mL), and the mixture was warmed to room temperature and then separated into aqueous and organic layers. The aqueous layer was extracted with dichloromethane (50 mL×2). The combined organic layers were washed with brine. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was then distilled off under reduced pressure. The obtained concentrated residue was purified by silica gel column chromatography (n-hexane/ethyl acetate) to obtain the title compound (7.8 g, 73%).

1. customseparated into aqueous and organic layers
2. extractionThe aqueous layer was extracted with dichloromethane (50 mL×2)
3. washThe combined organic layers were washed with brine
4. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
5. distillationthe solvent was then distilled off under reduced pressure
6. customThe obtained concentrated residue was purified by silica gel column chromatography (n-hexane/ethyl acetate)

ORD record

ord-65d1db9a13fa4ef8a9985382ab4afcc9

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08063223B2