100 mg (0.200 mmol) of ethyl 2-((6-chloro-3-((3-(trifluoromethoxy)phenyl)-ethynyl)imidazo[1,2-a]pyridin-2-yl)methylsulfonyl)acetate were dissolved in 2 ml of ethanol before adding 0.060 ml (0.599 mmol) of a 32% sodium hydroxide aqueous solution. The mixture was stirred at r.t. for 16 h. The solution was poured into 10 ml of water, acidified to an acid pH with acetic acid, extracted with 2×5 ml of dichloromethane, the combined organic phases were dried on Na2SO4 which was then removed by filtration and the obtained filtrate was concentrated in vacuo. 76 mg (yield=80%) of 2-((6-chloro-3-((3-(trifluoromethoxy)phenyl)ethynyl)-imidazo[1,2-a]pyridin-2-yl)methylsulfonyl)acetic acid were obtained as a yellow solid. LC-MS: m/z=473 (MH+) UV purity at 254 nm=99%. 1H NMR (300 MHz, DMSO) δ 14.72-12.20 (m, 1H), 9.00 (d, J=1.2 Hz, 1H), 7.88-7.76 (m, 3H), 7.62-7.45 (m, 3H), 4.96 (s, 2H), 4.42 (s, 2H).
