A mixture of 1-(1,1-dimethylethoxycarbonyl)-4-(butylamino)piperidine (VIII, EXAMPLE 86, 1.30 g), 2-chloro-3-nitropyridine (804 mg) and diisopropylethylamine (1.77 ml) in N-methyl-2-pyrrolidinone (15 ml) is stirred at 85° for 24 hrs, diluted with water (75 ml) and methylene chloride (150 ml), and the layers are separated. The aqueous phase is extracted with methylene chloride (2×25 ml) and the combined organic phase is washed with saline (25 ml), dried over sodium sulfate, and concentrated under reduced pressure at approximately 75°. The residue is chromatographed on silica gel (230-400 mesh, 100 g; eluting with ethyl acetate/hexane (5/95)) to give the title compound, NMR (CDCl3) 8.33, 8.05, 6.73, 4.20, 3.82, 3.30, 2.73, 1.84-1.71, 1.47, 1.40-1.20 and 0.86δ.
