| 摘要 |
PURPOSE:Acetophenone is used as a starting substance, it is allowed to react with chlorine or bromine in the presence of a silver compound and an acid to give directly the titled compound which is used as a starting substance for preparing intermediates of perfume components and agricultural chemicals. CONSTITUTION:The reaction of acetophenone with chlorine or bromine is conducted in an inert organic solvent containing chlorine or bromine atoms in its molecule such as carbon tetrachloride, ethyl bromide or chlorobromomethane, in the presence of a silver compound and an acid below room temperature, preferably at -30-10 deg.C, especially -20 deg.C--5 deg.C to give the objective compound of the formula (X is Cl, Br). Examples of suitable silver compounds are silver perchlorate, silver sulfate and silver oxide and the amount is more than 0.01mol, preferably 0.05-0.70mol per mol of acetophenone. As the acid, are mentioned perchloric acid, sulfuric acid and trifluoroacetic acid. |
