Water → HCID 19900723, compound

Participants

Reaction Steps

A mixture of 1-benzyl-2-formyl-4,5-diphenyl-imidazole (6.8 g), propane-1,3-diol (7.6 g) and polymer-bound pyridinium 4-toluenesulphonate (1.0 g) in toluene (250 ml) was stirred at reflux under a Dean & Stark water trap for 8 hours. TLC analysis (using a 1:1 v/v mixture of ethyl acetate and hexane) showed about 20% unreacted aldehyde. A further quantity of polymer-bound pyridinium 4-toluenesulphonate (250 mg) and propane-1,3-diol (3.5 g) were added, and the mixture was heated at reflux for a further period of 6 hours. After cooling to room temperature the mixture was decanted from the catalyst and washed with water (3×100 ml). The organic solution was dried over magnesium sulphate and evaporated, to give 1-benzyl-2-(1,3-dioxan-2-yl)-4,5-diphenylimidazole (7.2 g), in the form of a pale pink solid.

Provenance & Evidence