To a solution of 8-chloro-6-(trifluoromethyl)imidazo[1,2-a]pyridine-2-carboxylic acid (63 mg, 0.24 mmol, prepared as described in Example 1 Step C) in a 1:1 mixture of t-butanol (5 mL) and dichloromethane (5 mL) was added 4-(dimethylamino)pyridine (88 mg, 0.71 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (117 mg, 0.60 mmol). The reaction mixture was stirred for 15 min, after which time 1-ethyl-3-methyl-1H-pyrazole-4-sulfonamide (41 mg, 0.22 mmol, the product of Step A) was added, and the reaction mixture was stirred at room temperature overnight. Dichloromethane (100 mL) was added and the mixture was washed with 1 N hydrochloric acid (3×50 mL). The organic phase was separated, dried over magnesium sulfate, and concentrated under reduced pressure to afford a solid. The solid was suspended in a mixture of diethyl ether and hexane, filtered, and dried to afford 25 mg of the title compound, a compound of the present invention, as a solid, m.p. 189-190° C. 1H NMR (CDCl3) δ 9.85 (br s, 1H), 8.47 (s, 1H), 8.29 (s, 1H), 8.10 (s, 1H), 7.53 (s, 1H), 4.14 (q, 2H), 2.51 (s, 3H), 1.51 (t, 3H).
