[Synthesis]
A. General procedure for the synthesis of methyl 3-amino-2-methylbenzoate: 10 g (66.2 mmol) of 3-amino-2-methylbenzoic acid and 20 g of p-toluenesulfonic acid monohydrate were dissolved in 400 mL of methanol and the reaction was carried out at reflux overnight. After completion of the reaction, the reaction solution was diluted with a mixture of ethyl acetate and 1 M potassium carbonate solution. After cooling, the organic and aqueous layers were separated. The organic layer was washed sequentially with 1M potassium carbonate solution and saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated to give 9.23 g of an orange oily product in 85% yield. The product was characterized as follows: 1H NMR (CDCl3): δ 2.34 (s, 3H), 3.73 (br.s, 2H), 3.88 (s, 3H), 6.81 (d, J = 7.96 Hz, 1H), 7.05 (t, J = 7.78 Hz, 1H), 7.19-7.30 (m, 1H). IR (CHCl3): 3406, 3027, 3012, 2.30 (m). 3027, 3012, 2978, 2953, 1718, 1621, 1467, 1435, 1315, 1301, 1265, 1196, 1159, 1108, 1066, 1045, 810 cm-1. MS (FD): m/e 165 (M+, 100). |