Step 4: 5-bromo-1H-pyrrolo[2,3-c]pyridine (62 mg, 0.23 mmol) was dissolved in acetic acid (2 mL) and iron powder (127 mg, 2.28 mmol) was added at room temperature. The reaction mixture was heated to 70 °C and stirred for 2 hours. After completion of the reaction, it was cooled to room temperature and the mixture was poured into ethyl acetate (30 mL) and filtered through a diatomaceous earth pad. The filtrate was washed sequentially with 5% sodium bicarbonate solution, water and saturated brine and dried over anhydrous sodium sulfate. The solvent was concentrated under reduced pressure to afford the target compound 2-(2-bromo-5-nitropyridin-4-yl)-N,N-dimethylethylamine (25 mg, 56% yield).1H NMR (CDCl3) δ: 9.42 (1H, broad peak), 8.60 (1H, single peak), 7.74 (1H, single peak), 7.47 (1H, double peak, J=2.8 Hz), 6.54 ( 1H, double peak, J=2.8Hz).
