Hydrogen Peroxide → 6-Chloro-5-fluoroisatoic acid anhydride

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Reaction Steps

7.8 g (0.039 mol) of 4-chloro-5-fluoro-isatin are suspended in 50 ml of 100 percent acetic acid, treated with 0.25 ml of concentrated sulphuric acid and then 4.4 ml (0.043 mol) of 30 percent hydrogen peroxide are added dropwise thereto. The mixture is subsequently heated to 70° for 2.5 hours, then cooled to 10° and filtered. The crude product is recrystallized from acetone/hexane, there being obtained 6-chloro-5-fluoro-isatoic acid anhydride of melting point 275°-278° (decomposition).

Provenance & Evidence