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

Participants

Reaction Steps

To a stirred suspension of lithium borohydride (0.39 g; 18.0 mmol) in 25 mL THF at ambient temperature was added chlorotrimethylsilane (3.9 g; 36.0 mmol), dropwise over 2 minutes. Gas was evolved and the mixture warmed slightly. After stirring for 20 minutes, gas evolution had ceased, and argon gas was bubbled through the mixture for 2 minutes to try to remove the remaining trimethylsilane that had formed. A solution of 2-bromo-4-chloro-1-(2-nitrovinyl)benzene (1.18 g; 4.5 mmol) in 20 mL tetrahydrofuran was then added dropwise with stirring at ambient temperature over 4 minutes. The resulting mixture was stirred and heated to reflux. After 2 hours, the heat was removed, and after cooling to ambient temperature, the mixture was cooled in an ice bath and carefully quenched with 25 mL methanol. The solvent was evaporated, and the residue was partitioned between 50 mL of 20% KOH and 25 mL of dichloromethane. The organic layer was dried over sodium sulfate and evaporated to give 0.92 g of 2-(2-bromo-4-chlorophenyl)ethanamine as a cloudy yellow oil. MS (apci, pos) m/z=234.

Provenance & Evidence