Hydrazine → 1-Trifluoromethyl-3-(4'-fluorophenyl)-3-hydroxyurea

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Reaction Steps

p-Fluoronitrobenzene (14.1 grams; 0.1 mol) is dissolved in tetrahydrofuran (100 ml). Ten percent palladium on charcoal catalyst (0.1 gram) is added to the solution followed by hydrazine (6.0 ml; 0.1 mol), and the resulting mixture stirred at room temperature for about 48 hours with cooling as necessary. The reaction mixture, containing N-(4-fluorophenyl)hydroxylamine, is dried over anhydrous magnesium sulfate and filtered. To this solution is added trifluoromethyl isocyanate (11.1 grams; 0.1 mol) and the solution is stirred for about 15 minutes. The reaction mixture is concentrated by evaporation of solvent and the resulting precipitate is recovered by filtration to yield 1-trifluoromethyl-3-(4'-fluorophenyl)-3-hydroxyurea.

Provenance & Evidence