4-Ethoxybenzaldehyde → alpha-(4Ethoxyphenyl)-N-cyclopentylnitrone

Participants

Reaction Steps

4-Ethoxybenzaldehyde (22.0 g, 0.1467 mol) and N-cyclopentylhydroxylamine (14.1 g, 0.1398 mol) were mixed into toluene (200 mL) with p-toluenesulfonic acid monohydrate (1.0 g, 5.26 mmol). The mixture was refluxed for 3 hrs under argon atmosphere with a Dean-Stark trap to remove generated water. The solution was rotary evaporated to give a residue which was purified by flash chromatography over silica gel with EtOAc as an eluant and then recrystallization from a mixed solvent of hexanes and EtOAc. The title compound was obtained as a solid (21.24 g 65.1% yield), m.p. 95.1° C. (Rf=0.18 on a silica gel plate using hexanes:EtOAc, 2:1, v/v, as an eluant).

Provenance & Evidence