Synthesis
The general procedure for the synthesis of methyl 2-chloro-5-aminobenzoate from methanol and 5-amino-2-chlorobenzoic acid was as follows: to a stirred solution of 5-amino-2-chlorobenzoic acid (50 g, 291 mmol) in methanol (300 mL) was added chloromethane (45 mL, 605 mmol) dropwise at 0 °C. The reaction mixture was refluxed for 12 hours and then cooled to room temperature. Subsequently, the reaction mixture was concentrated under vacuum and the residue was dissolved in ethyl acetate (500 mL), washed with saturated aqueous sodium bicarbonate (3 x 100 mL), dried over anhydrous sodium sulfate and concentrated again under vacuum to give methyl 5-amino-2-chlorobenzoate as a light white solid (54 g, quantitative yield).LC/MS analysis: m/e Calculated value C8H8ClNO2 (M +H)+: 186.61, measured value: 185.9.
References
[1] Patent: WO2011/128251, 2011, A1. Location in patent: Page/Page column 180-181
[2] Patent: US2011/257151, 2011, A1. Location in patent: Page/Page column 67
[3] Patent: WO2007/60026, 2007, A1. Location in patent: Page/Page column 48-49
[4] Patent: EP1746099, 2007, A1. Location in patent: Page/Page column 18-19
[5] Journal of Medicinal Chemistry, 2009, vol. 52, # 8, p. 2465 - 2481
