Hydrazine hydrate (1:1) → 5-Chloro-4-(difluoromethyl)-N-[1-(tetrahydro-2H-pyran-4-yl)-4-piperidinyl]-1,2-benzenediamine

A stirred suspension of N-[5-chloro-4-(difluoromethyl)-2-nitrophenyl]-1-(tetrahydro-2H-pyran-4-yl)-4-piperidinamine (D97, 330 mg, 0.84 mmol) in ethanol (20 ml) at room temperature under argon was treated with Raney Nickel (20 mg) followed by dropwise addition of hydrazine hydrate (0.25 ml, 8.0 mmol). The mixture was maintained at room temperature for 30 minutes, then heated at 45° C. for 1 hr. The mixture was filtered through a pad of Kieselguhr and the filtrate concentrated under vacuum to leave the title compound as a yellow solid (180 mg of ˜88% purity, 59% yield).