Dimethyl Sulfate → 3-Bromo-6-chloro-2-fluoro-N-methylbenzenamine

Participants

Reaction Conditions

Reaction Steps

3-Bromo-6-chloro-2-fluoroaniline (1.2 g, 5.2 mmol) was dissolved in THF (12 mL) in a 100 mL round bottomed flask and treated with tetra-N-butyl ammonium bromide (0.015 g, 0.05 mmol) and powdered sodium hydroxide (0.83 g, 20.9 mmol) with stirring. After 5 minutes, the dark mixture was treated with dimethyl sulfate (1.3 g, 10.4 mmol) and the mixture heated at 60° C. for 2 hours. Analysis by TLC (hexanes: ethyl acetate/20:1) indicated some starting material remained. Added additional dimethyl sulfate (0.66 g, 5.2 mmol) and continued heating for 1.5 hour then stirred at room temperature overnight. The reaction was partitioned between diethyl ether and water and the layers separated and the aqueous phase extracted with ether. The combined ether layers were washed with water and dried (MgSO4). Filtration, concentration and purification by flash silica gel chromatography (hexanes) gave N-(3-bromo-6-chloro-2-fluorophenyl)-N-methylamine (0.81 g) as a colorless oil: 1H NMR (300 MHz, CDCl3): δ 6.93 (dd, 1H, J=8.4), 6.83 (dd, 1H), 4.00 (bs, 1H), 3.09 (d, 3H).

Provenance & Evidence