Ethanol → 6,7-Dihydro-5H-pyrrolo[1,2-a]imidazole-2-carboxaldehyde

Participants

Reaction Steps

28% Sodium methoxide (5.26 g) was added to the EtOH (250 mL) solution of 4,5-dihydro-3H-pyrrol-2-ylamine hydrochloride (3.27 g) at room temperature. After stirring for 5 min at room temperature, 2-bromo-3-propoxy-propenal (5.79 g) was added to the mixture at room temperature, then the reaction mixture was stirred for 1 h at room temperature. The reaction mixture was taken to dryness in vacuo. The residue was dissolved in CHCl3 (300 mL) and triethylamine (3.8 mL) was added. The mixture was heated to reflux for 3 hours. The reaction mixture was cooled to room temperature, washed with 50% K2CO3, dried over anhydrous K2CO3, filtered, and evaporated under reduced pressure. The residue was applied with silicagel column chromatography, eluted with CHCl3-acetone (2:1), and 6,7-Dihydro-5H-pyrrolo[1,2-a]imidazole-2-carbaldehyde (41%, 1.51 g) was obtained as a pale yellow solid.

Provenance & Evidence