Sodium periodate → 4-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole-5-carbaldehyde

Participants

Reaction Steps

A 1 L three-necked round bottom flask fitted with an overhead stirrer was dried and cooled under a stream of nitrogen then charged with 4-methoxy-5-styryl-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole (25 g, 0.074 mol, 1.0 equiv.) in dioxane (250 mL) and water (80 mL). To this solution was added sodium periodate (36.77 g, 0.17 mol, 2.3 equiv.) and osmium tetroxide (15 mL, 4% aq. soln.) at 0° C., and the reaction mixture was stirred at RT overnight. The reaction mixture was quenched with ice cold water (1 L) and extracted with EtOAc (2×750 mL). The organic layers were combined, washed with brine (500 mL), dried (Na2SO4), filtered and concentrated in vacuo. The crude material was purified by SiO2 chromatography eluting with an EtOAc/hexane gradient (40-50% EtOAc) to afford 4-methoxy-1-(tetrahydro-pyran-2-yl)-1H-benzoimidazole-5-carbaldehyde (15 g, 77%) as a pale yellow solid.

Provenance & Evidence