A mixture of 4-{3-[1-(4-methoxyphenyl)cyclopropyl][1,2,4]triazolo[4,3-b][1,2,4]triazin-6-yl}benzoic acid (isomer-I from step 2, 14.0 mg, 0.0361 mmol), cyclopropylamine (3.76 μL, 0.0542 mmol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (16.0 mg, 0.0361 mmol) and N,N-diisopropylethylamine (25.2 μL, 0.145 mmol) in DMF (1.0 mL) was stirred at RT for 3 h. The mixture was diluted with methanol and purified by RP-HPLC (pH=10) to give the desired product. Analytical LCMS: (M+H)+=427.3.
