Isobutyl chloroformate (0.061 g, 0.448 mmol) was dropwise added into an ice cold solution of 4-diethylamino-2-butynoic acid (0.104 g, 0.672 mmol) and N-methylmorpholine (0.068 g, 0.672 mmol) in 10 mL of tetrahydrofuan under N2. After stirring for 30 min, a solution of 0.1 g (0.32 mmol) of 6-amino-4-[(3-chloro-4-fluorophenyl)-amino]-3-quinolinecarbonitrile in 1.5 mL of pyridine was added dropwise and the mixture was stirred at 0° C. for 1.5 hr. The reaction was quenched with ice water, poured into saturated sodium bicarbonate and brine, and extracted with ethyl acetate. The ethyl acetate layer was concentrated and purified by thin-layer chromatography eluted with 15% methanol in ethyl acetate. The product was collected, and dried in vacuo to give 0.046 g (32%) of light brown solid; ESMS m/z 450.2, (M+H+); mp 117-120° C.
