Synthesis
3-Bromo-5-aminobenzoic acid (1.0 g, 4.62 mmol) was stirred in methanol (15mL) with ice cooling, and the yellow solution was treated with thionyl chloride (4.00 mL, 55.0 mmol) dropwise over 20 mm. The resulting mixture was allowed to warm to room temperature and left stirring overnight. The reaction mixture was quenched with aqueous saturated NaHCO3 solution at 0 C. The solvent was then removed under vacuum, and the residue was suspended in ethyl acetate (200 mL). The organic phase was washed with brine (100 mL), dried (Na2504) and concentrated to afford Methyl 3-amino-5-bromobenzoate as a yellow solid (1.08 g, 98%). NMR (400 MHz, Methanol-d) oe 7.10 (t, J 1.6 Hz, 1H), 6.83 (t, J 1.6 Hz, 1H), 6.57 (t, J= 1.6 Hz, 1H), 3.46 (s, 3H). 13C NMR (100 MHz, CDC13) oe: 52.3, 114.6, 121.6, 122.3, 122.9, 132.6, 147.7, 166.0. m/z (ESI, MH) 231.
References
[1] Tetrahedron, 2010, vol. 66, # 42, p. 8254 - 8260
[2] Patent: WO2004/50619, 2004, A1. Location in patent: Page 21
[3] Chirality, 2015, vol. 27, # 8, p. 487 - 491
[4] Journal of the American Chemical Society, 2013, vol. 135, # 46, p. 17408 - 17416
[5] Patent: WO2014/19685, 2014, A1. Location in patent: Page/Page column 13; 39; 40
