Synthesis
2-Amino-4-chlorobenzoic acid (I; 20.00 g, 116.6 mmol) and acetonitrile (300 mL) were added to a 500 mL single-necked round-bottomed flask with rapid stirring to form a beige-colored suspension. At room temperature, N-bromosuccinimide (NBS; 20.75 g, 116.6 mmol) was added slowly in batches. After addition, the reaction mixture was continued to be stirred for 1 hour. Subsequently, the reaction mixture was placed in a 45 °C water bath and the solvent was removed by rotary evaporation. Water was added to the residue, stirred and the filter cake was washed by filtration. Finally, the product was dried under vacuum at 60 °C to afford 2-amino-5-bromo-4-chlorobenzoic acid (II; 28.62 g, 98% yield).
References
[1] Patent: CN106986809, 2017, A. Location in patent: Paragraph 0024; 0025; 0026; 0027; 0028; 0029; 0030
[2] Patent: CN106966914, 2017, A. Location in patent: Paragraph 0019; 0020; 0028; 0029; 0036; 0037
[3] Patent: US2015/119405, 2015, A1. Location in patent: Paragraph 0407; 0408; 0409
[4] Patent: WO2005/54238, 2005, A1. Location in patent: Page/Page column 70
[5] Organic and Biomolecular Chemistry, 2014, vol. 12, # 27, p. 5031 - 5037
