To a solution of 6-[2-anilino-1-(anilinocarbonyl)-2-oxoethyl]nicotinic acid (35 mg, 0.093 mmol) in DMF (1 mL) at room temperature was added EDCI (22 mg, 0.11 mmol) and HOBT (14 mg, 0.10 mmol). The solution was stirred for 30 min and 1,2-phenylenediamine (34 mg, 0.31 mmol) was added in one portion. The reaction mixture was stirred at room temperature for 18 h and purified by reverse phase HPLC (5% to 80% MeCN in water) to give 2-(5-{[(2-aminophenyl)amino]carbonyl}pyridin-2-yl)-N,N′-diphenylmalonamide (16 mg, TFA salt, 21% from methyl 6-[2-anilino-1-(anilinocarbonyl)-2-oxoethyl]nicotinate) as a white solid: ESIMS calcd 466.2 (M++H), found 466.1 (M++H).
