Dibromomethane → HCID 11407519, compound

Temperature

-70 °C

Under nitrogen gas, a solution of diisopropylamine (2.4 g, 21.6 mmol) in tetrahydrofuran (10 mL) was added to n-butyllithium (in 1.6 M hexane, 13.5 mL, 21.6 mmol) at 5° C. and the mixture was stirred for 30 minutes (liquor A). Separately, under nitrogen gas in another vessel, a solution was prepared from methyl (S)-2-tert-butyloxycarbonylamino-3-phenylpropanoate (2.0 g, 7.2 mmol), dibromomethane (2.5 g, 14.4 mmol) and tetrahydrofuran (10 mL) and cooled to −70° C. (liquor B). To this liquor B was added said liquor A over 30 minutes at −70° C., and the mixture was stirred for 30 minutes at the same temperature and then warmed to 20° C. This reaction mixture was poured in 25 mL of2N-HCl for hydrolysis and, then, extracted with 10 mL of ethyl acetate. The organic layer was washed with 20 mL of water, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to recover 2.670 g of black solid. This solid was recrystallized from ethyl acetate/hexane to provide brown crystals of tert-butyl (S)-(1-benzyl-3,3-dibromo-2-oxo-propyl)carbamate (630 mg, 92.2 area %, yield 19%).

1. additionTo this liquor B was added
2. customover 30 minutes
3. customat −70° C.
4. stirringthe mixture was stirred for 30 minutes at the same temperature
5. temperaturewarmed to 20° C
6. extractionextracted with 10 mL of ethyl acetate
7. washThe organic layer was washed with 20 mL of water
8. dry with materialdried over anhydrous magnesium sulfate
9. concentrationconcentrated under reduced pressure
10. customto recover 2.670 g of black solid
11. customThis solid was recrystallized from ethyl acetate/hexane

ORD record

ord-e5e0215e84224a7eae514a1d0f558c3c

Source dataset

uspto-grants-2003_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06573399B1