5-Nitro-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-3-carbaldehyde (150 mg, 0.545 mmol) and 4-(2-methylmorpholino)benzene-1,2-diamine (113 mg, 0.545 mmol) were dissolved in THF (10 mL) and 2N HCl (1 drop) was added. The solution was heated at a gentle reflux for 30 min. Then, 1N sodium bisulfite (104 mg, 1 mmol; 2 mL of a 1N solution) was added and heated at reflux (70° C.) overnight. The solution was cooled to room temperature, and diluted with ethyl acetate (40 mL). The mixture was washed with water and brine, dried over Na2SO4, and concentrated. Purification by flash chromatography (5% CH3OH/CH2Cl2) afforded the title compound (140 mg). 1H NMR: (400 MHz, CDCl3): δ 9.56 (d, 1H, J=1.6 Hz), 8.28 (m, 1H), 7.74 (d, 1H, J=8.8 Hz), 7.64 (m, 1H), 7.36 (m, 1H), 7.03-6.96 (m, 1H), 5.75 (dd, 1H, J=2.8 and 6.4 Hz), 3.99 (m, 2H), 3.79 (m, 3H), 3.38 (m, 2H), 2.84 (m, 1H), 2.51 (m, 2H), 2.11 (m, 2H), 1.86 (m, 1H), 1.74 (m, 2H), 1.22 (d, 3H, J=6.4 Hz).
