Dimethylformamide → 2-n-Butyl-4-chloro-1-(4-bromobenzyl)-5-formylimidazole

Participants

Reaction Conditions

Reaction Steps

1.61 g of 1-(4-bromo-benzyl)-2-butyl-1,5-dihydroimidazol-4-one and 10 ml of toluene are loaded into a round-bottom flask. The mixture is cooled down to 0–5° C., then added dropwise with 1.4 ml of phosphorous oxychloride. The temperature is slowly allowed to reach 90° C. and 1.2 ml of dimethylformamide are added dropwise. The mixture is heated at 115° C. for 2 h, then cooled to room temperature and added with 50 ml of toluene, 100 g of crushed ice and 10 g of celite. Stirring is continued for 30 minutes, then the pH is adjusted to 8 with 30% aqueous NaOH and the precipitate is filtered off using a Buchner funnel. The organic phase is concentrated under vacuum and chromatographed eluting with 1:1 v/v hexane-diethyl ether. 380 mg of product (IV) as a colourless oil is obtained.

Provenance & Evidence