Module 5- Naphthalene derivatives - naphthaquinones- 1-naphthaquinone- 2-naphthaquinone- amphi naphthaquinone- preparation-Reactions

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3. Preparation of naphthaquinones
There are three isomeric naphthaquinones.
i) Oxidation of 4-amino-1-naphthol with acidified potassium dichromate gives -
naphthaquinone.
ii) Oxidation of naphthalene with CrO3 / CH3COOH also gives -naphthaquinone.
iii) Oxidation of 1-amino-2-naphthol with FeCl3/HCl gives -naphthaquinone.

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iv) Oxidation of 2, 6 - dihydroxy naphthalene with PbO2 gives amphi
naphthaquinone.
-Naphthaquinone is also prepared by the oxidation of 1,4-Dihydroxy
naphthalene and naphthalene as given below
Reactions of naphthaquinone
i) -Naphthaquinone is reduced by zinc and HCl to 1,4-dihydroxynaphthalene. On
oxidation it gives phthalic acid.
ii) It forms a monoxime which exhibits tautomerism.

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iii) On reaction with nitrous acid it is converted to 1,3-diketohydrindene.
Prepared by
Dr. A. Syed Mohamed
HoD and Senior Assistant Professor, Research Dept. of Chemistry
Sadakathullah Appa College (Autonomous)
Tirunelveli, Tamilnadu, India. asm2032@gmail.com
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.