To a solution of 8-chloro-6-(trifluoromethyl)imidazo[1,2-a]pyridine-2-carboxylic acid (110 mg, 0.42 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 (152 mg, 1.25 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (96 mg, 0.5 mmol). The reaction mixture was stirred for 15 min after which time 3-chloro-1-ethyl-1H-pyrazole-4-sulfonamide (81 mg, 0.38 mmol, the product of Step D) was added and stirring was continued at room temperature overnight. Dichloromethane (100 mL) was then added and the mixture was extracted with 1 N hydrochloric acid (3×50 mL). The separated organic phases were combined, 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 and filtered to afford 85 mg of the title compound, a compound of the present invention, as a solid, m.p. 184-185° C. 1H NMR (CDCl3) δ 9.96 (br s, 1H), 8.47 (s, 1H), 8.29 (s, 1H), 8.16 (s, 1H), 7.54 (s, 1H), 4.17 (q, 2H), 1.54 (t, 3H).
