Sulfuric Acid → 4-(1,3-Dioxo-1,3-dihydroisoindol-2-yl)-2-pentafluorosulfanylbenzonitrile

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Reaction Conditions

Reaction Steps

0.46 ml (8.24 mmol) of semiconcentrated sulfuric acid was slowly added dropwise at 0° C. to a solution of 1 g (2.74 mmol) of 2-(4-amino-3-pentafluorosulfanylphenyl)isoindole-1,3-dione (prepared in example 5) in acetic acid. The mixture was stirred at 0° C. for 10 min; then a solution of 189.4 mg of sodium nitrite in 2 ml of water was slowly added dropwise with stirring, and the resulting solution was stirred at 0° C. for 30 min. This solution was finally added dropwise to a solution, cooled to 0° C., of 246 mg (2.74 mmol) of copper(I) cyanide and 536 mg (8.23 mmol) of potassium cyanide in 5 ml of water. The reaction mixture was stirred at 0° C. for 30 min and afterward at room temperature for another 3 h. After the end of the reaction, the mixture was added to water and the aqueous phase extracted twice with ethyl acetate. The organic phase was dried over magnesium sulfate and filtered, the filtrate was concentrated and the residue purified chromatographically on silica gel first with toluene and then with 20/l toluene/ethyl acetate. 4-(1,3-Dioxo-1,3-dihydroisoindol-2-yl)-2-pentafluorosulfanylbenzonitrile was obtained. 1H NMR (500 MHz; d6-dmso: δ [ppm]=8.4 (m, 2H); 8.1-7.95 (m, 5H).

Provenance & Evidence