372 PRACTICAL ORGANIC CHEMISTRYsolution: iodine is liberated, the quinone simultaneously undergoingreduction.Anthraquinone does not liberate iodine from KI solution.3.Sodium hydroxide.Dissolve a few crystals of benzoquinone in10% aqueous NaOH solution and shake gently. The solution turnsrapidly brown and then almost black owing to atmospheric oxidation.Alizarin dissolves in aqueous NaOH solution giving a purple solu-tion. Calcium hydroxide will precipitate a blue salt from this solution.Anthraquinone is unaffected by NaOH solution.Oxidation, (a) Ammoniacal silver nitrate.To a few ml. of ammoniacalAgNO3(preparation, p. 525), add a few drops of cold aqueous benzo-quinone solution: a silver mirror or (more generally) a dark precipitateof metallic silver is formed in the cold.(b)Alkaline permanganate.Heat under reflux i g. of i,2-naph-thoquinone, 50 ml. of saturated aqueous KMnO4solution and2 g. of anhydrous Na2CO3for 30 minutes. Then proceed as foroxidation of benzyl chloride (p. 393). i,2-Naphthoquinone gives
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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.