To a solution of the methylsulfoxide (32 mg, 0.41 mmol, 6.0 eq) in 1 mL of methylene chloride was added oxalyl chloride (2M, 0.135 mL, 0.27 mmol, 4.0 eq) at −78° C. After 15 minutes, the 4-(2-(cyclohexylmethylamino)benzo[d]oxazol-6-yloxy)pyridine-2-carboxamide (25 mg, 0.068 mmol, 1.0 eq) in 2 mL of methylene chloride was added to the reaction mixture. After being stirred at that temperature for 20 minutes, triethyl amine (83 mg, 0.83 mmol, 12 eq) was added to mixture. The reaction mixture was stirred at −78° C. for 2 hours, and then was quenched with aqueous ammonium chloride solution. The resulting mixture was extracted with ethyl acetate (2×20 mL). The combined organic layers were washed with water (5 mL), brine (5 mL), then dried over MgSO4, filtered, and evaporated under reduced pressure to give crude product, which was purified by reverse phase prep HPLC to give the title compound. MH+=349.0.
