A mixture of ethyl N-tert-butoxycarbonyl-4-(3-nitrobenzyl)-piperidine-4-carboxylate (0.85 g, 2.17 mmol; Example 69, Step A) and 5% palladium on charcoal (0.06 g) in ethanol (100 mL) was hydrogenated at room temp. at 50 psi overnight. The resultant mixture was filtered through a plug of Celite, and the filtrate was concentrated under vacuum. The residue was dissolved in pyridine (5 mL), treated with methanesulfonyl chloride (0.24 mL, 3.2 mmol), and heated at 60° C. for 3 h. The product mixture was concentrated under vacuum, and the residue was subjected to column chromatography on silica gel eluting with 2% methanol in chloroform. Collection and concentration of appropriate fractions provided the title compound.
