230 mg (1.08 mmol) 1-cyclopropyl-isoquinoline-3-carboxylic acid and 391 mg (1.08 mmol) 2,2-dimethyl-piperazine-1-carboxylic acid benzyl ester trifluoroacetate was stirred with 385 mg (1.20 mmol) TBTU and 640 μL (3.70 mmol) DIPEA in 3 mL DMF at RT for 1 h. The mixture was worked up by adding water, followed by extraction with EtOAc. Then the reaction mixture was washed with saturated aqueous NaHCO3 solution. The combined organic phases were dried over sodium sulfate, filtered and concentrated in vacuo. Yield: 600 mg (99%), purity: 80%; ESI-MS: m/z=444 (M+H)+; Rt(HPLC): 1.42 min (method 5)
