Chlorotrimethylsilane → 2-(4-Bromo-2-chlorophenyl)ethanamine

To a stirred suspension of lithium borohydride (0.29 g, 13 mmol) in tetrahydrofuran (20 mL) at ambient temperature was added chlorotrimethylsilane (3.4 mL, 27 mmol), dropwise over 2 minutes. After stirring at ambient temperature for 20 minutes, argon gas was bubbled through the mixture for 2 minutes to remove the remaining trimethylsilane that had formed. A solution of 4-bromo-2-chloro-1-(2-nitrovinyl)benzene (0.88 g, 3.4 mmol) in tetrahydrofuran (15 mL) was added dropwise over 4 minutes with stirring at ambient temperature. The resulting mixture was stirred and heated to reflux for 1 hour. The mixture was cooled in an ice bath and carefully quenched with methanol (20 mL). The solvent was evaporated, and the residue was partitioned between 20% potassium hydroxide (40 mL) and dichloromethane (20 mL). The organic layer was dried over sodium sulfate and concentrated to afford 2-(4-bromo-2-chlorophenyl)ethanamine as a light yellow oil (0.75 g, 95% yield).

1. customargon gas was bubbled through the mixture for 2 minutes
2. customto remove the remaining trimethylsilane that
3. customhad formed
4. stirringwith stirring at ambient temperature
5. stirringThe resulting mixture was stirred
6. temperatureheated
7. temperatureto reflux for 1 hour
8. temperatureThe mixture was cooled in an ice bath
9. customcarefully quenched with methanol (20 mL)
10. customThe solvent was evaporated
11. customthe residue was partitioned between 20% potassium hydroxide (40 mL) and dichloromethane (20 mL)
12. dry with materialThe organic layer was dried over sodium sulfate
13. concentrationconcentrated

ORD record

ord-c825e284809e47eea335f2a50cd059a7

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08569522B2