Methyl iodide → 4,6-Dichloro-1-methyl-1H-pyrrolo[3,2-c]pyridine

A solution of 4,6-dichloro-1H-pyrrolo[3,2-c]pyridine (270 mg, 1.44 mmol) in tetrahydrofuran (4 mL) at 0° C. was treated with a 60% dispersion of sodium hydride in mineral oil (69.3 mg, 2.89 mmol) followed by iodomethane (225 mg, 1.59 mmol). After stirring at 0° C. for 0.5 h, the reaction mixture was allowed to warm to room temperature and was stirred at room temperature for 5 h. At this time, the resulting mixture was quenched with a saturated aqueous sodium bicarbonate solution. The reaction mixture was extracted with ethyl acetate. The combined organics were washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated in vacuo. Flash chromatography (30% ethyl acetate/hexanes) afforded 4,6-dichloro-1-methyl-1H-pyrrolo[3,2-c]pyridine (278 mg, 95.8%). LC-MS calcd. for C8H6Cl2N2 [(M+H)+] 201, obsd. 200.8.