3,4-dihydro-2H-pyran → 4-bromo-6-methoxy-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole

Participants

Reaction Steps

A round-bottom flask was charged with 4-bromo-6-methoxy-1H-indazole (1.00 g, 4.40 mmol), TsOH monohydrate (39 mg, 0.22 mmol), 3,4-dihydro-2H-pyran (1.48 g, 17.6 mmol), and THF (40 mL). The reaction mixture was degassed with nitrogen and refluxed for 18 h, and the solvent was then removed in vacuo. The residue was purified by SiO2 chromatography to afford 4-bromo-6-methoxy-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole (1.53 g, quantitative) as a yellow solid. MS (ESI) m/z: 311.2 [M+1]+.

Provenance & Evidence