Hydrochloric Acid → 1-[4-(1-Imidazolyl)-phenyl]-2-propanone

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Reaction Steps

A 5.0 liter 3-neck flask fitted with a condenser, addition funnel, and mechanical stirrer is charged with a mixture of 218.4 g (0.954 mole) of 1-[4-(2-nitro-1-propenyl)phenyl-1H-imidazole, 449 g (8.04 mole) of iron powder (325 mesh), 6.4 g of FeCl3 6H2O, 350 ml of methanol and 760 ml of water. The mixture is heated to reflux with stirring and 450 ml of concentrated hydrochloric acid is added dropwise over a period of 2.5 hours. Refluxing is continued for two to three hours. The reaction mixture is cooled to room temperature, 1.9 liter of CH2Cl2 was added, and the mixture stirred rapidly for one hour. This is filtered, the inorganic solid is washed three times with 500 ml portions of CH2Cl2, and the layers separated. The CH2Cl2 layer is dried over MgSO4, then filtered through a bed of silica gel (600 g, 70-230 mesh), which is washed with 5 liters of CH2Cl2 and then with 13 liters of 10% methanol in methylene chloride. Evaporation of the solvent gave 126.7 g of a brown oil which crystallized on standing. The product is purified via the sodium bisulfate addition product to give a product having a mp of 71.5°-72.5° C.

Provenance & Evidence