Acetic Acid → (R)-4-Bromostyrene oxide

Temperature

0 °C

To a magnetically stirred solution of (R,R)-(−)-N,N′-Bis(3,5-di-tert-butyl-salicylidene-1,2-cyclohexane-diaminocobalt(II) (4.88 g, 8.09 mmol) in toluene (50 mL) at room temperature in an open flask, was added acetic acid (4.6 mL, 80.0 mmol). The mixture was stirred for 1 h. The mixture was then concentrated to give a brown solid, which was placed under high vacuum overnight. The brown residue was taken up in THF (50 mL) and the resulting solution was added to 2-(4-bromophenyl)oxirane (199.62 g, 1.0 mol) in THF (150 mL). The reaction mixture was cooled to 0° C. and distilled water (10.0 mL, 556 mmol) was added dropwise over 5 minutes into the mixture. The resulting mixture was warmed to room temperature and stirred for 18 h. The reaction mixture was concentrated and then 5% EtOAc/Hexane (500 mL) was added to the residue. The insoluble material was filtered off. The filtrate was concentrated and the resulting brown oil was diluted with hexane (500 mL). The insoluble material was removed by filtration and the filtrate was concentrated to give a brown oil. The crude material was purified by vacuum distillation at 90° C. to give (2R)-2-(4-bromophenyl)oxirane as a clear oil (72.7 g, 365 mmol, 82%) which solidified upon cooling to a white solid.

1. concentrationThe mixture was then concentrated
2. customto give a brown solid, which
3. customwas placed under high vacuum overnight
4. additionwas added dropwise over 5 minutes into the mixture
5. temperatureThe resulting mixture was warmed to room temperature
6. stirringstirred for 18 h
7. concentrationThe reaction mixture was concentrated
8. addition5% EtOAc/Hexane (500 mL) was added to the residue
9. filtrationThe insoluble material was filtered off
10. concentrationThe filtrate was concentrated
11. additionthe resulting brown oil was diluted with hexane (500 mL)
12. customThe insoluble material was removed by filtration
13. concentrationthe filtrate was concentrated
14. customto give a brown oil
15. distillationThe crude material was purified by vacuum distillation at 90° C.

ORD record

ord-ad51808e760c443eb7dbd8a140d3808e

Source dataset

uspto-grants-2010_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07749998B2