Dimethylformamide → 4-(3-dimethylaminopropyl)-3,5-dimethyl-1H-pyrrole-2-carbaldehyde

Participants

Reaction Steps

To the ice-cooled solution of N,N-dimethylformamide (6.0 mL, 76 mmol) in dichloromethane (30 mL) was added phosphorus oxychloride (7.0 mL, 76 mmol) dropwise. Upon addition of phosphorus oxychloride, the reaction mixture was stirred at room temperature for 15 minutes and a solution of [3-(2,4-dimethyl-1H-pyrrol-3-yl)-propyl]-dimethyl-amine (6.8 g, 38 mmol) in dichloromethane (20 mL) was added dropwise at 0° C. The final reaction mixture was refluxed at 60° C. for 4 hours and cooled with ice bath. Ice cube was added to the reaction mixture slowly followed by addition of 2 N sodium hydroxide to adjust pH to 12. The reaction mixture was stirred at room temperature for 30 minutes and extracted with ethyl acetate. The organic-layer was washed with brine, dried over anhydrous sodium sulfate and concentrated to give crude product which was purified on a silica gel column eluting with dichloromethane-methanol-ammonium hydroxide (9:1:0.01) to give 5 g (63%) of 4-(3-dimethylamino-propyl)-3,5-dimethyl-1H-pyrrole-2-carbaldehyde as a dark red oil.

Provenance & Evidence