Synthesis
Step A: 2-Amino-3-methylbenzoic acid (10.0 g, 66 mmol) was dissolved in DMSO, followed by the addition of 48% aqueous hydrogen bromide solution (18.0 mL). The reaction mixture was stirred at room temperature overnight, and upon completion of the reaction, the reaction was quenched with saturated sodium bicarbonate solution. The resulting mixture was continued to be stirred overnight and the precipitate was subsequently collected by filtration and dried under vacuum to afford 2-amino-5-bromo-3-methylbenzoic acid (13.0 g, 85% yield) as a pink solid. The product was characterized by 1H NMR (500 MHz, DMSO): δ 7.69 (d, J = 1.0 Hz, 1H), 7.33 (d, J = 1.0 Hz, 1H), 2.10 (s, 3H); mass spectrum (ESI+) m/z 231 ([M + H]+).
References
[1] Patent: EP2842946, 2015, A1. Location in patent: Paragraph 0309; 0728; 0729
[2] Journal of Agricultural and Food Chemistry, 2012, vol. 60, # 44, p. 10942 - 10951
[3] Journal of Organic Chemistry, 2006, vol. 71, # 16, p. 5921 - 5929
[4] Patent: WO2011/8572, 2011, A2. Location in patent: Page/Page column 70
[5] Patent: WO2008/65508, 2008, A1. Location in patent: Page/Page column 29-30
