3,4-dihydro-2H-pyran → 4-bromo-1-(tetrahydro-2H-pyran-2-yl)-1H-benzo[d]imidazole

Participants

Reaction Steps

A mixture of 4-bromo-1H-benzo[d]imidazole (1.5 g, 7 mmol), TsOH.H2O (0.1 g, 0.7 mmol), and 3,4-dihydro-2H-pyran (2.9 g, 35 mmol) in THF (10 mL) was heated at reflux overnight. The reaction mixture was concentrated in vacuo. To the residue was added water and the mixture was extracted with EtOAc. The combined extracts were dried (MgSO4), filtered, and concentrated in vacuo. The residue was purified by SiO2 chromatography using a petroleum ether/EtOAc gradient (10:1 to 3:1) to afford 4-bromo-1-(tetrahydro-2H-pyran-2-yl)-1H-benzo[d]imidazole as a gray solid (1.6 g, 75%). MS (ESI): m/z=281 [M+1]+.

Provenance & Evidence