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 25° C. 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 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. temperatureto warm to 25° C. overnight (20 h)
3. temperatureThe black slurry was cooled down to −78° C.
4. temperatureto warm to −40° C.
5. stirringstirred for an additional 30 min
6. waitAfter this period
7. customA precipitate formed
8. filtrationwas filtered off
9. additionThe mother liquor was diluted with EtOAc (150 mL)
10. washthe organic layer washed with saturated NaCl (50 mL)
11. dry with materialThe organic layer was dried over MgSO4
12. filtrationfiltered
13. concentrationconcentrated

ORD record

ord-c5b768dcbde0450c98d49badaf5ce697

Source dataset

uspto-grants-2009_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07547725B2