REACTIONS AND IDENTIFICATION 387 p-Nitrophenol is reduced similarly and the product does not give a yellow coloration with alkali. 4. Ferric chloride coloration. Add FeCl 3 solution to a few crystals (or to an aqueous solution) of p-nitrophenol: a violet-red coloration is produced. o-Nitrophenol does not give a coloration. 6. Acetylation. Heat i g. of p-nitrophenol with 5 ml. of an acetic acid-acetic anhydride mixture under reflux for 15 minutes. Pour into water: the solid acetate separates. Filter, wash with water and re-crystallise from ethanol: m.p. 77-5°. This treatment usually leaves 0-nitrophenol unchanged. The addition, however, of about 0-5 ml. of cone. H 2 SO 4 to the acetylating mixture gives the o-derivative, m.p. 40°. CRYSTALLINE DERIVATIVES FOR IDENTIFICATION. (A) Benzoyl Derivative. Since acetylation and benzoylation do not always proceed smoothly with nitrophenols, it is best to reduce them to the aminophenol as in (3) above. Add an excess of 20% aqueous sodium hydroxide to the reaction mixture after reduction, cool and
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This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.