[Synthesis]
General procedure for the synthesis of 6-bromo-2-methyl-1H-indole (CXXXIII): 3-bromoaniline (4 g, 0.041 mmol), copper(II) acetate monohydrate (14.0 g, 0.129 mmol), palladium(II) acetate (0.1 g, 0.000801 mmol), and acetone (100 mL) were combined in a dimethyl sulfoxide (50 mL) The solution was heated at 90 °C for 24 hours. After completion of the reaction, the reaction mixture was poured into cold water and extracted with ethyl acetate (2 x 250 mL). The organic layers were combined, washed sequentially with water and brine, and then dried over anhydrous sodium sulfate. The organic layer was concentrated under reduced pressure to give the crude product. The crude product was purified by silica gel column chromatography (100-200 mesh) to afford the target compound CXXXIII (1.3 mg, 27% yield) using hexane solution of 5% ethyl acetate as eluent. The product characterization data were as follows: 1H NMR (400 MHz, CDCl3): δ 7.83 (brs, 1H), 7.40 (s, 1H), 7.34 (d, J=8.3 Hz, 1H), 7.14 (dd, J=8.5,1.7 Hz, 1H), 6.17 (s, 1H), 2.41 (s, 3H); MS (ESI, positive mode) m/z 208/210 (MH+, 79/81Br). |