Polynuclear hydrocarbons module7

Polynuclear hydrocarbons module7

• 1.
  1 | Pa g e 1. Preparation of anthraquinone 1) From anthracene: It is manufactured by the vapour phase air oxidation of crude anthracene. 2) Synthetic method: Friedel-Craft condensation of phthalic anhydride with benzene in the presence of AlCl3 forms an intermediate which on heating with H2SO4 cyclizes to give anthraquinone. Reactions of anthraquinone i) Distillation with zinc dust: It forms anthracene on distillation with ZnCl2/NaCl/Zn dust at 200-300oC. ii) Reduction: With tin and HCl in acetic acid it forms anthrone; with Zn/HCl in acetic acid the main product is dianthryl; with Zn and NH4OH it gives 9, 10-dihydroanthrol; and with zinc and NaOH the main product is anthraquinol which is tautomeric with oxanthrol.
• 2.
  2 | Pa g e iii) Nitration: Nitration of anthraquinone gives 1-or a-nitro-anthraquinone. iv) Sulphonation: Anthraquinone on sulphonation with oleum in presence of catalyst mercuric sulphate at 120oC gives mainly -anthraquinone-sulphonic acid, whereas in the absence of catalyst at 140oC the main product is -anthraquinonesulphonic acid.
• 3.
  3 | Pa g e Prepared by Dr. A. Syed Mohamed HoD and Senior Assistant Professor, Research Dept. of Chemistry Sadakathullah Appa College (Autonomous) Tirunelveli, Tamilnadu, India. [email protected] The author ackowledges Prof. H. Kassali Rahmathullah, Dr. T. Syed Ismail, Dr. M. Kamalutheen, Former Professor, Dept. of Chemistry, Sadakathullah Appa College for their valuable contribution.