A mixture of 410 mg (2.28 mmol) 6-methoxy-2-pyridinecarboxylic acid and 400 μL (3.02 mmol) 1-chloro-N,N,2-trimethylpropenylamine in 10 mL THF was stirred at RT. After 1.5 h, 600 mg (2.66 mmol) 3,3-dimethyl-piperazine-1-carboxylic acid tert-butyl ester and 1.00 mL (5.81 mmol) DIPEA was added and the reaction mixture was stirred at RT for 30 min. The reaction mixture was diluted with saturated NaHCO3 solution and extracted with EtOAc. The combined organic phases were dried over sodium sulfate, filtered and concentrated in vacuo. The crude material was purified by flash chromatography (PE/EtOAc=1/1).
