p-Toluenesulfonic acid → 5-Iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole

Participants

Reaction Steps

To a mixture of 5-iodo-1H-indazole (0.90 g, 3.69 mmol) and 3,4-dihydro-2H-pyran (1.57 g, 18.7 mmol) in dry dichloromethane (20 mL), was added p-TsOH (0.08 g, 0.41 mmol) at room temperature. The resulting mixture was stirred overnight. Upon completion, saturated aqueous NaHCO3 (30 mL) was added slowly into the reaction mixture. The organic layer was separated, dried over Na2SO4, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (0˜5% EtOAc in petroleum ether) affording the title compound (1.0 g). 1H NMR (400 MHz, DMSO-d6): δ 8.21 (s, 1H), 8.08 (s, 1H), 7.67 (dd, 1H), 7.61 (d, 1H), 5.85 (dd, 1H), 3.88-3.85 (m, 1H), 3.78-3.72 (m, 1H), 2.41-2.29 (m, 1H), 2.05-1.95 (m, 2H), 1.77-1.72 (m, 1H), 1.61-1.56 (m, 2H).

Provenance & Evidence