p-Toluenesulfonic acid → 2-(2,5-Diphenyl-pyrrol-1-ylimino)-3-(2,5-dipyridine-3-yl-pyrrol-1-ylimino)-butane

Participants

Reaction Steps

A suspension of 3-(2,5-Diphenyl-pyrrol-1-ylimino)-butan-2-one (1.0 g, 3.4 mmol) in toluene (12 ml) is treated with DMF (6 ml), 2,5-di-pyridin-3-yl-pyrrol-1-ylamine (850 mg, 3.6 mmol) and p-toluene sulfonic acid (30 mg). The resulting suspension is fitted with a Dean Stark trap and heated to reflux with azeotropic removal of water in an oil bath until no starting materials remain by TLC. The solution is cooled to rt and concentrated in vacuo. The residue is purified by flash chromatography to afford 2-(2,5-diphenyl-pyrrol-1-ylimino)-3-(2,5-dipyridine-3-yl-pyrrol-1-ylimino)-butane.

Provenance & Evidence