64-18-6

87034-76-2

7205-46-1

Using 6-chloro-N4-methylpyridine-3,4-diamine (3.0 g, 19.0 mmol) and trimethyl orthoformate (50 mL) as raw material, formic acid (1.0 mL) was added and the reaction was stirred for 3 hours at 100 °C. Upon completion of the reaction, the mixture was cooled to room temperature and the solvent was evaporated under reduced pressure. The residue was poured into sodium bicarbonate solution and extracted with ethyl acetate. The organic phases were combined, washed sequentially with water and saturated saline and dried over anhydrous sodium sulfate. The organic phase was concentrated under reduced pressure to give a brown solid crude product. Purification by column chromatography (eluent: 30% ethyl acetate/dichloromethane) afforded 6-chloro-1-methyl-1H-imidazo[4,5-c]pyridine as a light brown solid (2.7 g, 85% yield). The structure of the product was confirmed by 1H NMR (400 MHz, DMSO-d6): δ 8.75 (1H, d, J=0.89 Hz), 8.39 (1H, s), 7.84 (1H, d, J=0.90 Hz), 3.86 (3H, s). LC-MS analysis showed a retention time of Rt=1.97 min, and the molecular ion peak [M+H]+ of 168 .