67-56-1

745048-63-9

474330-54-6

General procedure for the synthesis of methyl 5-amino-2-bromo-4-methylbenzoate from methanol and 5-amino-2-bromo-4-methylbenzoic acid: 5-amino-2-bromo-4-methylbenzoic acid (39.90 g, 0.17 mol) was suspended in methanol (500 mL). The suspension was cooled to 0 to 5 °C and thionyl chloride (40 mL, 0.54 mol) was added slowly and dropwise. The reaction mixture was heated to reflux for 6 hours. Upon completion of the reaction, the solution was concentrated under reduced pressure and the residue was diluted with ice water (500 g). The pH was adjusted to 7.5 with saturated aqueous sodium bicarbonate and subsequently extracted with ethyl acetate (3 x 200 mL). The organic phases were combined, washed with saturated saline (3 x 200 mL), dried over anhydrous magnesium sulfate, filtered and concentrated to dryness under reduced pressure to afford methyl 5-amino-2-bromo-4-methylbenzoate as a white solid (40.35 g, 95% yield).