Triethylamine (75 mL, 0.54 mol) was slowly added to a solution of 2,4-dichloro-3-nitroquinoline (André et al, U.S. Pat. No. 4,988,815, Example 2, 114 g, 0.470 mol) in anhydrous 1-methyl-2-pyrrolidinone (NMP) (450 mL), and the resulting black solution was cooled to 0° C. A solution of 1,2-diamino-2-methylpropane (42 g, 0.54 mol) in anhydrous NMP (42 mL) was added dropwise over a period of three hours. After the addition was complete, the reaction was allowed to warm to ambient temperature, stirred for five hours, and poured slowly into warm water (4 L) with vigorous stirring. A yellow precipitate formed, and the suspension was stirred for one hour at ambient temperature. The precipitate was isolated by filtration and washed with cold water until the filtrate was colorless. The solid was dissolved in dichloromethane (4 L), and the resulting solution was washed sequentially with saturated aqueous sodium carbonate and brine, dried over magnesium sulfate and sodium sulfate, filtered through a layer of CELITE filter agent, and concentrated under reduced pressure to provide 130 g of N1-(2-chloro-3-nitroquinolin-4-yl)-2-methylpropane-1,2-diamine as a bright yellow powder.
