1-Fluoro-2-nitrobenzene → tert-Butyl (1-(2-nitrophenyl)piperidin-4-yl)carbamate

A solution of 1-fluoro-2-nitro-benzene (0.50 mmol, 53 μL), N,N-diisopropylethylamine (0.50 mmol, 87 μL) and Piperidin-4-yl-carbamic acid tert-butyl ester (0.50 mmol, 0.10 g) in 1,4-dioxane (2 mL) was irradiated using microwave for 10 minutes at a temperature of 180° C. The solution was then cooled to room temperature and concentrated in vacuo and the resulting residue was purified using column chromatography on silica gel to provide [1-(2-Nitro-phenyl)-piperidin-4-yl]-carbamic acid tert-butyl ester (0.12 g, 77% yield). To the solution of this nitro compound in EtOAc (15 mL) was added Pd on carbon (5% Pd, 55 mg). The resulting reaction mixture was stirred under a hydrogen atmosphere at room temperature for about 15 hours. The reaction mixture was filtered through a pad of celite and the filtrate was concentrated in vacuo to provide Intermediate Compound 42A (97 mg, 86% yield).