N-bromobutanimide → HCID 68428555, compound

Temperature

-15 °C

A slurry of copper bromide (I)-dimethyl sulfide complex (1.57 g, 7.66 mmol) in THF (20 mL) and dimethyl sulfide (10 mL) as co-solvent was cooled to −40° C. and ethyl magnesium bromide (5 mL, 15.3 mmol) was added dropwise for 10 min. The slurry was stirred for 40 min while warming to −15° C. The greenish slurry was cooled to −40° C. and (4R)-4-benzyl-3-[(2E)-5,5,5-trifluoropent-2-enoyl] 1,3-oxazolidin-2-one (2 g, 6.38 mmol) was added dropwise as a solution in THF (5 mL) at −40° C. The reaction was allowed to warm to 250C overnight (20 h). The black slurry was cooled down to −78° C. and N-bromosuccinimide (2.3 g 12.76 mmol) was added portionwise. It was allowed to warm to −40° C. and stirred for an additional 30 min. After this period, the black slurry became greenish to blue. A precipitate formed and was filtered off. The mother liquor was diluted with EtOAc (150 mL) and the organic layer was washed with saturated NaCl (50 mL). The organic layer was dried over MgSO4, filtered and concentrated to afford (4R)-4-benzyl-3-[(2R, 3S)-2-bromo-3-ethyl-5,5,5-trifluoropentanoyl]-1,3-oxazolidin-2-one as a green semi-solid (1.6 g, 59.5%). Mass Spectrum (−ESI): 421, 420 (M−H)−.

1. temperatureThe greenish slurry was cooled to −40° C.
2. temperatureThe black slurry was cooled down to −78° C.
3. temperatureto warm to −40° C.
4. stirringstirred for an additional 30 min
5. waitAfter this period
6. customA precipitate formed
7. filtrationwas filtered off
8. additionThe mother liquor was diluted with EtOAc (150 mL)
9. washthe organic layer was washed with saturated NaCl (50 mL)
10. dry with materialThe organic layer was dried over MgSO4
11. filtrationfiltered
12. concentrationconcentrated

ORD record

ord-f83c140ef6b740ca92f14661f0abd906

Source dataset

uspto-grants-2007_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07300951B2