| 摘要 |
HOE 91/F 320 of the disclosure Process for the preparation of 2,4-dichlorofluorobenzene Process for the preparation of 2,4-dichlorofluorobenzene in high yield and purity without intermediate separation of the isomers formed, (1) by nitrating 1 mol of fluorobenzene to give nitrofluorobenzene using a mixture comprising 35 to 65 parts by weight of 50 to 90% strength sulfuric acid and 35 to 65 parts by weight of a nitrating acid comprising 35 to 55 parts by weight of 95 to 98% strength sulfuric acid and 45 to 65 parts by weight of 96 to 98% strength nitric acid, with the proviso that 0.8 to 2.0 equivalents of the nitrating agent NO2+ are used per mol of fluorobenzene, at 20 to 90.degree.C, (2) allowing 25 g to 150 g of chlorine, in the presence of a ring chlorinating catalyst, to act on each 100 g of the crude nitrofluorobenzene mixture obtained, at 20 to 100.degree.C, and (3) allowing about 18 g to about 203 g of chlorine or equivalent amounts of a chlorine releasing agent to act on each 100 g of the crude chlorofluoronitrobenzene mixture obtained, after removal of the ring chlorinating catalyst, at 110 to 220.degree.C, and isolating the 2,4-dichlorofluorobenzene.
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