To a solution of (S)-2-{2-[6-amino-7-chloro-3-(3,5-dimethylphenyl)-2-oxo-1,2-dihydro-quinolin-4-yloxy]-ethyl}-piperidine-1-carboxylic acid tert-butyl ester (700 mg in 13 mL dry methylene chloride) at 0° C. was added 0.33 mL pyridine followed by 158 mg triphosgene and the mixture allowed to stir at 0° C. for 1 hour. At this time 0.46 mL of cyclopropylamine was added via syringe and the reaction mixture warmed to room temperature. After 2 hours, the mixture was diluted with 200 mL ethyl acetate and washed with saturated ammonium chloride (100 mL) and brine (100 mL). The organic portion was dried over magnesium sulfate then concentrated in vacuo. The crude product was purified by crystallization from ethyl acetate to give the title compound (615 mg).
