Boron tribromide → Methyl 3-bromo-5-(butylamino)-4-hydroxybenzoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a −78° C. solution of the Methyl 3-bromo-5-(butylamino)-4-methoxybenzoate (520 mg) in methylene chloride (10 mL) was added BBr3 (8 ml of 1.0 M solution in methylene chloride) dropwise and the reaction mixture was stirred for 18 h. The mixture was concentrated under reduced pressure, and the residue was dissolved in methylene chloride and saturated sodium bicarbonate was added. The mixture was cooled to 0° C. and methanol was added dropwise. After stirring for 30 min, the mixture was stirred at room temperature for 1 h. The solvent was removed, and the residue dissolved in methylene chloride, washed with water, saturated sodium bicarbonate (15 mL), and brine, dried (magnesium sulfate), filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica, 1:20, ethyl acetate/hexanes) provided 440 mg of the title compound: 1H NMR (300 MHz, CDCl3) δ 7.52, 7.19, 3.88, 3.18, 1.65, 1.46, 0.97.

Herkunft & Nachweise