GENERAL METHOD: 4.0 g of 5-bromo-1H-indole-3-carboxylic acid was dissolved in 40 times the volume (400 mL) of methanol and a catalytic amount of concentrated sulfuric acid was slowly added. The reaction mixture was heated to reflux for 5 hours, followed by slow cooling to room temperature. Ice-cold water was added to the cooled mixture and the yellow solid was collected by filtration. The solid was recrystallized from ethanol to give methyl 5-bromo-indole-3-carboxylate (12b) as a yellow solid in 62% yield. The product characterization data were as follows: melting point: 210-212 °C; IR (KBr, cm-1): 3213, 3114, 2929, 1745; 1H NMR (400 MHz, CDCl3): δ 3.93 (3H, s, -OCH3), 7.28 (1H, d, J = 8.8 Hz, Ar-H), 7.35 (1H, m, Ar-H ), 7.91 (1H, d, J = 2.8 Hz, Ar-H), 8.32 (1H, s, Ar-H), 8.67 (1H, s, -NH); 13C NMR (400 MHz, CDCl3 + DMSO-d6): δ 49.93, 105.91, 112.88, 113.75, 122.40, 124.26, 126.65, 131.89, 134.33, 164.13; HRMS (m/z): calculated value C10H9NO2Br [M]+: 253.98112, measured value: 253.98102.
