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

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.

1. stirringthe reaction mixture was stirred for 1 h at room temperature
2. temperatureThe mixture was heated
3. temperatureto reflux for 3 hours
4. temperatureThe reaction mixture was cooled to room temperature
5. washwashed with 50% K2CO3
6. dry with materialdried over anhydrous K2CO3
7. filtrationfiltered
8. customevaporated under reduced pressure
9. washeluted with CHCl3-acetone (2:1)

ORD record

ord-c73ea02fce4f428eab6f4f26e4a6bcfb

Source dataset

uspto-grants-2006_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07112582B2