| 摘要 |
Fluorinated benzils and a process for their preparation A process for the preparation of fluorinated benzils of the formula (1) (1) in which X1-X6, R1, R2, R3 and R4 are hydrogen, fluorine, chlorine or bromine atoms, or alkyl(C1-C10), phenyl or naphthyl groups which may be substituted, or are groups reducing the electron density, at least one of the substituents X1-X6 being a fluorine atom, by reacting 1 mol of a benzil of the formula (1), in which X1-X6 and R1 and R2 have the abovementioned meanings, with the proviso that at least one of the substituents X1-X6 is a chlorine atom, with about 0.8 to about 2.5 mol of potassium fluoride, rubidium fluoride, cesium fluoride or tetraalkyl (C1-C18)-ammonium fluoride per chlorine atom to be exchanged, at temperatures of from about 100.degree.C to about 280.degree.C, possibly in the presence of a phase transfer catalyst and a dipolar aprotic or nonpolar solvent, and the new benzils prepared by this process.
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