1,3-Dibromo-5,5-dimethylhydantoin → 3'-Bromo-2,2,2-trifluoro-5'-(trifluoromethyl)acetophenone

To a solution of 5.00 g of 2,2,2-trifluoro-5′-(trifluoromethyl)acetophenone in 1 mL of acetic acid and 6 mL of concentrated sulfuric acid, 3.54 g of 1,3-dibromo-5,5-dimethylhydantoin was added and the resultant mixture was stirred at 35° C. for 3.5 hours. After the completion of the reaction, the reaction mixture was charged into 60 mL of ice water and the resultant mixture was extracted with chloroform (30 mL×2). The organic phase was washed with a saturated sodium hydrogen carbonate aqueous solution (50 mL×1) and then dehydrated and dried over saturated saline and anhydrous magnesium sulfate in this order, and the solvent was distilled off under reduced pressure. The resultant residue was dissolved in 20 mL of hexane and an insoluble substance was filtered off, followed by distilling off the solvent under reduced pressure to obtain 6.50 g of the objective substance as a yellow oily substance. This substance was used in the next process as it was without being further purified.

1. customAfter the completion of the reaction
2. extractionthe resultant mixture was extracted with chloroform (30 mL×2)
3. washThe organic phase was washed with a saturated sodium hydrogen carbonate aqueous solution (50 mL×1)
4. dry with materialdried over saturated saline and anhydrous magnesium sulfate in this order
5. distillationthe solvent was distilled off under reduced pressure
6. dissolutionThe resultant residue was dissolved in 20 mL of hexane
7. filtrationan insoluble substance was filtered off
8. distillationby distilling off the solvent under reduced pressure
9. customto obtain 6.50 g of the objective substance as a yellow oily substance

ORD record

ord-7ae79283344f43728c40686a71797fc8

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08318757B2