IMidazo[1,2-a]pyridine-2-carboxylic acid, 8-(trifluoroMethyl)- synthesis

Yield:1018828-72-2 60%

Reaction Conditions:

Stage #1: 8-trifluoromethyl-imidazo[1,2-a]pyridine-2-carboxylic acid methyl esterwith water;sodium hydroxide in tetrahydrofuran at 20; for 2 h;
Stage #2: with hydrogenchloride in water;

Steps:

103.2

A mixture of 8-trifluoromethyl-imidazo[1,2-a]pyridine-2-carboxylic acid methyl ester (0.5 g, 2 mmol) and NaOH (2M, 4 mmol) was stirred at room temperature in THF/H₂O (3:1 v/v, 100 mL) for 2 hours. The reaction mixture was concentrated and the residue was acidified with 10% HCl and extracted with DCM (2×80 mL). The organic layer was washed with brine (50 mL), dried (MgSO₄), filtered and concentrated to afford 8-trifluoromethyl-imidazo[1,2-a]pyridine-2-carboxylic acid as a light yellow powder (60%) which was used without further purification. MS (ESI) m/z=231 (MH⁺).

References:

US2010/204265,2010,A1 Location in patent:Page/Page column 131