Imidazole → 3-(1H-Imidazol-1-yl)phenol

Participants

Reaction Steps

Imidazole (34 g, 0.5 mole), m-bromoanisole (51 ml, 0.4 mole), potassium carbonate (52 g), and cuprous chloride (2.4 g) in 300 ml N-methyl-2-pyrrolidone was heated at reflux for 4 hours. The cooled mixture was diluted with water and 100 ml concentrated ammonium hydroxide. The product was extracted into toluene-ethyl acetate (several times until TLC of aqueous layer showed only a trace amount of product). All the organic extracts were combined, filtered, extracted once with water and then three times with a total of 300 ml 48% hydrobromic acid. The hydrobromic acid extracts were combined and heated at reflux for 6 hours and then concentrated. The residue was redissolved in water and basified first with sodium hydroxide and at the end with sodium bicarbonate to get a final pH of 8. Some isopropyl ether was added to cause the product to crystallize. The solid was collected by filtration, washed with water, and dried at 80° C. in a vacuum oven to obtain 50.9 g (79.5% yield). A small portion of this solid was dissolved in absolute ethanol, filtered, concentrated, and recrystallized. The recrystallized material melted at 169°-170° C.

Provenance & Evidence