6188-25-6

107-20-0

1072-98-6

6188-25-6

General procedure for the synthesis of 6-chloroimidazo[1,2-A]pyridine from chloroacetaldehyde and 2-amino-5-chloropyridine: 2-amino-5-chloropyridine (4.50 g, 35.00 mmol) and 2-chloroacetaldehyde (10.30 g, 52.50 mmol, 8.45 mL) in a solvent mixture of ethanol (50.00 mL) and water (10 mL) were reacted at 80 °C The reaction was stirred for 16 hours. Upon completion of the reaction, the reaction solution was concentrated to dryness and the resulting residue was diluted with water (100 mL) and subsequently extracted with ethyl acetate (150 mL x 2). The organic phases were combined, washed sequentially with water (50 mL × 2) and saturated saline (20 mL), dried over anhydrous sodium sulfate, filtered and concentrated to afford 6-chloroimidazo[1,2-A]pyridine (5.10 g, 33.43 mmol) as a solid product. The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3): δH 8.18 (d, 1H), 7.65 (s, 1H), 7.59-7.50 (m, 2H), 7.12 (dd, 1H).