Synthesis
General method: 3-Amino-4-bromobenzoic acid (1 eq.) was dissolved in methanol and cooled to 0°C. The mixture was then heated to 0°C and refluxed for 24 hours. Thionyl chloride (2.5 eq.) was added slowly and the reaction mixture was heated to reflux for 24 hours after completion of the addition. After completion of the reaction, the solvent was removed by evaporation and the residue was neutralized with saturated aqueous NaHCO3 solution. Subsequently, the mixture was extracted with ethyl acetate, the organic layers were combined and dried with anhydrous magnesium sulfate. Finally, the target product, methyl 3-amino-4-bromobenzoate, was purified by column chromatography (hexane/ethyl acetate as eluent).
References
[1] European Journal of Medicinal Chemistry, 2014, vol. 76, p. 343 - 351
[2] Journal of Medicinal Chemistry, 2016, vol. 59, # 6, p. 2423 - 2435
