Imidazo[1,2-a]pyridine-3-carboxylic acid

Synthesis

To a three-necked flask, add 0.94 mL of 10 mmol 2-aminopyridine solution, 3.4 mL of 20 mmol DMF, and 10 mL of isopropanol. Stir until homogeneous, then heat in a water bath to 65 °C and react for 2 h. After the reaction is complete, evaporate the solvent to obtain the intermediate. Dissolve the intermediate in 10 mL of DMF, add 15 mmol of saturated sodium carbonate solution and 15 mmol of ethyl bromoacetate, stir until homogeneous, and then heat to 85 °C. After the reaction is complete, analyze by thin-layer chromatography, dry with anhydrous sodium sulfate, and then concentrate under reduced pressure.

The crude product was separated by silica gel column chromatography, using ethyl acetate/n-hexane (1:6) as the eluent to obtain pure IMIDAZO[1,2-A]PYRIDINE-3-CARBOXYLIC ACID ethyl ester. Imidazole[1,2-A]pyridine-3-carboxylic acid ethyl ester was added to an ethanolic solution of potassium hydroxide (10.1 g potassium hydroxide, 73 ml ethanol), heated to reflux, and reacted for 1 hour. TLC was used for detection. After the reaction was complete, the reaction solution was concentrated, 50 ml of water was added, and the pH was adjusted to 2 with concentrated hydrochloric acid. The mixture was extracted with ethyl acetate, and the organic phases were combined, washed with saturated brine, dried over sodium sulfate solid, and concentrated to obtain the compound IMIDAZO[1,2-A]PYRIDINE-3-CARBOXYLIC ACID.

Application

Imidazolo[1,2-a]pyridine-3-carboxylic acid is a grayish-white solid that can be widely used in industries such as sensing fluorescent probes, analytical detection, and pharmaceuticals. It has become a research hotspot for organic chemists and medicinal chemists.