| 摘要 |
PURPOSE: Provided are a process for the preparation of 3,5-bis-(trifluoromethyl)benzoyl chlorides from the corresponding 3,5-dimethylbenzoic acids and novel 3,5-bis(trihalogenomethyl)- and 3,5-dimethylbenzoyl halides that arise as intermediates in the process. CONSTITUTION: 3,5-bis(trifluoromethyl)benzoyl chlorides optionally substituted with fluorine or chlorine are advantageously prepared by converting 3,5-dimethylbenzoic acids optionally substituted with fluorine or chlorine into the corresponding acid chlorides; completely free-radically chlorinating the chlorides in the side chains, giving 3,5-bis(trichloromethyl)benzoyl chlorides optionally substituted by fluorine or chlorine; fluorinating the latter with anhydrous hydrogen fluoride and/or antimony pentafluoride, giving 3,5-bis(trifluoromethyl)benzoyl fluorides optionally substituted with fluorine or chlorine; and then reacting the 3,5-bis(trifluoromethyl)benzoyl fluorides with silicon tetrachloride in the presence of a further Lewis acid. Some of the 3,5-bis(trihalogenomethyl) and 3,5-dimethylbenzoyl halides which arise as intermediates are novel compounds. |
