Imidazole → HCID 13176303, compound

Participants

Reaction Steps

23 g of crude 5-bromo-5-(4-chlorophenoxy)-3,3-dimethylpent-1-en-4-one, dissolved in 30 ml of acetonitrile, were added dropwise to a solution of 28.6 g (0.42 mol) of imidazole in 250 ml of acetonitrile, in the course of 5 minutes. The mixture was then heated to the boil for a further 3 hours and the solution was concentrated under reduced pressure. The oily residue was taken up in 200 ml of ethyl acetate and the mixture was washed with three times 50 ml of water. After the organic phase had been dried over anhydrous sodium sulphate, it was concentrated by evaporation, the residue was taken up in 200 ml of acetone and a filtered solution of 20.2 g (0.07 mol) of naphthalene-1,5-disulphonic acid in 100 ml of acetone was added. The precipitated salt was filtered off under suction, 100 ml of water and 100 ml of dichloromethane were added to it, and the mixture was then rendered alkaline with 10% strength sodium carbonate solution. The organic phase was separated off and concentrated. The oily residue crystallized on trituration with ether/petroleum ether. 7.4 g (34.7% of theory) of 5-(4-chlorophenoxy)-3,3-dimethyl-5-(imidazol-1-yl)-pent-1-en-4-one of melting point 72° to 74° C. were obtained.

Provenance & Evidence